فهرست مطالب

اطلاعات جغرافیایی (سپهر) - پیاپی 106 (تابستان 1397)

نشریه اطلاعات جغرافیایی (سپهر)
پیاپی 106 (تابستان 1397)

  • تاریخ انتشار: 1397/06/18
  • تعداد عناوین: 16
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  • یاسین کاظمی، سعید حمزه *، سید کاظم علوی پناه، بهرام بهرام بیگی صفحات 5-20
    سنجش از دور حرارتی، با فراهم آوردن قابلیت محاسبه دمای سطح زمین با استفاده از تصاویر ماهواره ای، نقش مهمی در مطالعات محیط زیستی از جمله مطالعات اقلیمی، شناسایی گسل های پنهان و یا در مواردی پی جویی منابع زمین گرمایی ایفا می کند. در این مقاله با استفاده از اطلاعات بدست آمده از باند های حرارتی ماهواره لندست 8، دمای سطح زمین در لحظه تصویربرداری از منطقه ای دارای گسل های بیسمنتی محاسبه گردیده است. اطلاعات حرارتی حاصل از منطقه محاط بر گسل شهداد و قسمت جنوبی گسل نایبند، که در محدوده ی شرقی شهرستان کرمان قرار دارند، مورد تجزیه و تحلیل قرار گرفته اند. نتایج این تحقیق نشان داد که در نزدیکی زون مرکزی این دو گسل عمیق و بزرگ تجمع های حرارتی سطحی وجود دارد. طبق نتایج بدست آمده از پژوهش حاضر این تجمعات حرارتی با فاصله گرفتن از زون مرکزی گسل کاهش می یابد. بر اساس انطباق موقعیت گسل ها و پیکسل های دمای بالا، تجمع های خطی حرارتی می توانند کلیدی جهت شناسایی گسل های اصلی در مناطق با لیتولوژی و سن مشابه در نقشه های بدست آمده از دمای سطح زمین باشند. در مطالعه حاضر با توجه به موقعیت گسل ها و نقشه های دمایی، دو منطقه ی با حداکثر تمرکز نمودارهای هم دمای مشمول کران بالای طیف دمایی نقشه LST منطقه، استخراج و ارائه گردیده است. با توجه به شیب نمودارهای هم دما به سمت زون مرکزی گسل در مناطق مذکور، و با توجه به نزدیک بودن عمق گسل های بیسمنتی به مواد داغ تشکیل دهنده آستنوسفر زمین، مناطق معرفی شده می توانند به عنوان پتانسیل اولیه وجود منابع زمین گرمایی مورد بررسی تفصیلی واقع شوند.
    کلیدواژگان: سنجش ازدورحرارتی، LST، انرژی زمین گرمایی، ناهنجاری های حرارتی، گسل شهداد، گسل نایبند
  • بهنام تشیع *، محمد شریف صفحات 21-35
    در سال های اخیر، مطالعه رفتار اشیاء نقطه ای و تجزیه و تحلیل خطوط سیر آن ها در علوم مختلف، بویژه در علوم اطلاعات مکانی[1]، مورد توجه بسیاری از محققان قرار گرفته است. مطالعاتمذکوربه درک صحیح الگوهای رفتاری-حرکتی این اشیاء کمک شایانی می کنند. نحوه حرکت اشیاء تا حد زیادی متاثر از زمینه ای است که حرکت در آن صورت می پذیرد. به همین دلیل،تحلیل خطوط سیر اشیا صرفا با در نظر گرفتن ابعاد مکانی و مکانی-زمانی به درستی شرایط حین حرکت را منعکس نمی کند و منجر به نتایج غیرواقعی می شود.با این حال، روش های موجود اندازه گیری فاصله تنها قادر به اندازه گیری تشابه خطوط سیر در ابعاد مکانی و مکانی-زمانی هستند و معمولا بعد زمینه را نادیده می گیرند. بنابراین، در این تحقیق، روشی نوین توسعه داده شده است، تا بتوان از طیف وسیعی از اطلاعات زمینه ای کمی و کیفی داخلی و خارجی در کنار ابعاد مکانی-زمانی در فرآیند اندازه گیری تشابه خطوط سیر غیر هم اندازه استفاده کرد. در توسعه روش مذکور، از سیستم هایاستنتاج فازی برای مدلسازی تشابه خطوط سیر با استفاده از انواع داده های حرکتی و اطلاعات زمینه ای بهره گرفته شده است. برای افزایش کارایی روش پیشنهادی از ساختار سلسله مراتبی مبتنی بر مسئله و تولید و تنظیم همزمان توابع عضویت و مجموعه قواعد از طریق یادگیری استفاده شده است. عملکرد این سیستم با اعمال آن برروی مجموعه خطوط سیر واقعی افراد پیادهودوچرخه سوار به همراه اطلاعات زمینه ای آنها حین حرکت مورد ارزیابی قرار گرفته است. نتایج بیانگرکارآمدی روش پیشنهادی در اندازه گیری زمینه-آگاه خطوط سیر با اندازه های گوناگون و در ابعاد مختلف است.
    [1]3-Geospatial Information Science
    کلیدواژگان: خط سیر، اندازه گیری تشابه، زمینه، آگاهی، HFIS، بهینه سازی چندهدفه
  • علی کلانتری اسکویی *، مهدی صابر خوشه مهر صفحات 37-55
    اشتراک گذاری از موضوعات کلیدی در موفقیت زیرساخت اطلاعات مکانی (SDI) محسوب می شود. در سایه اشتراک گذاری از دوباره کاری ها در تولید و جمع آوری داده و اطلاعات مکانی توسط سازمان های مختلف جلوگیری شده، هزینه ها کاهش یافته و از قابلیت های داده و اطلاعات مکانی در راستای برنامه ریزی ها و تصمیم گیری ها به طور موثری استفاده به عمل می آید. اما شواهد موجود نشان می دهند که تحقق امر اشتراک گذاری داده و اطلاعات مکانی همواره با چالش های متعددی مواجه بوده است و بدون رفع این موانع دستیابی به اهداف توسعه SDI نیز میسر نخواهد شد. ازاین رو هدف اصلی تحقیق حاضر، ارائه راهکاری برای شناسائی و اولویت بندی چالش های اشتراک گذاری داده و اطلاعات مکانی می باشد. چارچوب روش تحقیق بر اساس پیمایش، مفهوم ریسک و استفاده از سامانه استنباط فازی بنا نهاده شده است. به منظور عینیت بخشیدن به این چارچوب، مطالعه ای موردی با مشارکت 19 سازمان در استان آذربایجان شرقی انجام شد. ابتدا از منابع مختلف 25 چالش محتمل در اشتراک گذاری شناسائی شد و سپس با کمک پرسشنامه دیدگاه کارشناسان در رابطه با احتمال وقوع و شدت اثر چالش ها مورد سنجش قرار گرفت. در مرحله بعد با توسعه سامانه استنباط فازی دیدگاه های کارشناسان پردازش شده و امتیاز فازی هر یک از چالش ها محاسبه شد. در ادامه چالش ها از نظر اهمیت بر اساس معیارهای از پیش تعریف شده سطح بندی شده و با اجرای آنالیز خوشه ای(کلاستر) چالش های مشابه در کلاسترهای یکسان قرار گرفتند. بر اساس یافته ها، میانگین هندسی کلی چالش ها 76/62 درصد محاسبه شد و نبود پورتال مکانی (ژئوپورتال)، فقدان یا مشکلات متادیتا (فراداده)، نبود هماهنگی لازم در بین سازمان های مختلف برای اشتراک گذاری داده و اطلاعات مکانی از مهم ترین چالش های اشتراک گذاری داده و اطلاعات مکانی شناخته شدند که همگی در کلاستر یکسانی قرار داشتند. همینطور از ارزیابی چالش ها در دو کلاس سازمانی و فنی چنین استنباط شد که چالش های سازمانی نسبت به چالش های فنی اهمیت بیشتری دارند.
    کلیدواژگان: استاندارد، پورتال مکانی، زیرساخت داده مکانی، متادیتا، موانع، هماهنگی
  • سعیده زمانی، مجید رحیم زادگان * صفحات 57-69
    تبخیر از دریاچه پشت سدها و دریاچه های آب شیرین از جمله روش های هدررفت منابع آب است. به همین دلیل اندازه گیری مقدار تبخیر از سطح پهنه های آب شیرین اهمیت بسیاری در مدیریت منابع آب دارد. روش های گوناگونی برای اندازه گیری تبخیر-تعرق ارائه شده که از جمله آن ها الگوریتم توازن انرژی در سطح (SEBAL) است که می تواند با استفاده از تصاویر ماهواره ای نقشه های پهنه بندی تبخیر-تعرق تولید نماید. تا به حال، الگوریتم SEBAL بیشتر در برآورد تبخیر-تعرق از سطح خشکی ها و پوشش های گیاهی پیاده سازی شده و تحقیقات کمی در زمینه کاربرد آن در سطح پهنه های آبی شیرین انجام شده است. هدف این تحقیق، بکارگیری الگوریتم SEBAL جهت پهنه بندی تبخیر از سطح دریاچه های پشت سدها است. به همین منظور سه تصویر Landsat TM از دریاچه سد امیرکبیر (کرج) و زمین های کشاورزی پایین دست آن مربوط به ماه های خرداد، تیر و مرداد سال 0931 تهیه گردید و تصحیحات رادیومتریک و هندسی بر روی آن انجام شد. برای انجام پیاده سازی های الگوریتم SEBAL، از داده های ایستگاه هواشناسی کرج استفاده شد. همچنین مقدار تبخیر اندازه گیری شده از روش تشت تبخیر توسط شرکت آب منطقه ای استان تهران در نزدیکی دریاچه سد امیرکبیر به عنوان داده های واقعیت زمینی استفاده گردید. RMSE نتایج به دست آمده از SEBAL برای سد امیرکبیر با داده های زمینی، 72/0 میلیمتر بود که مقدار قابل قبولی محسوب می شد . مقدار تبخیر روزانه نیز از کل سطح دریاچه در تاریخ های منتخب به ترتیب 730/8، 346/01 و 534/5 متر در روز به دست آمد. علاوه بر این، نتایج نشان دهنده افزایش تبخیر از سطح مخزن سد در مناطق کم عمق به سمت مناطق عمیق تر بود که این مورد می تواند نشان دهنده کارایی نامناسب روش های نقطه ای اندازه گیری تبخیر باشد. در مجموع، نتایج بیانگر کارایی الگوریتم SEBAL برای برآورد تبخیر از سطح دریاچه های سدها بود و می توان با توجه به شرایط مکانی و زمانی هر منطقه، از آن برای تعیین تبخیر پهنه های آبی شیرین استفاده نمود.
    کلیدواژگان: الگوریتم SEBAL، تبخیر، تعرق، تصاویرماهواره ای، دریاچه سد، پهنه بندی
  • اکبر مرادی *، محمدرضا ملک صفحات 71-85
    امروزه صنعت گردشگری و جذب گردشگر به عنوان یکی از منابع اقتصادی در کشورهایی باسابقه ی فرهنگی و تاریخی از جمله ایران، مورد توجه بسیار قرارگرفته است. گردشگران نیاز به اطلاعات ساختار یافته ای دارند که در هرلحظه و هر مکان در دسترسشان باشد. این اطلاعات به آن ها کمک می کند که موقعیت خود را نسبت به مکانی که به احتمال زیاد برای آن ها جدید و ناآشنا باشد، توجیه کنند. هم چنین آن ها سرویس های اطلاعات مکانی از قبیل مکان های مورد نظرشان و بهترین مسیری که به آن ها ختم می شود نیز می باشند. در سیستم های بافت آگاه با بررسی بافت های جاری کاربر رفتار خود را بر اساس این بافت ها منطبق می کنند. در این مقاله نحوه پیاده سازی یک سیستم بافت آگاه گردشگری برای شهر مراغه شرح داده شده است. سیستمی که علاوه بر موقعیت مکانی گردشگر، از یک سری بافت های دیگر مانند بافت جهت حرکت، بافت سرعت حرکت، مسیر و بافت زمان نیز برای استنباط شرایط گردشگران و تطبیق سیستم با این شرایط استفاده می کند. نتایج حاصل از ارزیابی سیستم نشان می دهد حدود 33/83 درصد از کارشناسان گردشگری و گردشگران از سیستم پیاده سازی شده راضی بودند و آن را برای استفاده سایر گردشگران پیشنهاد می دادند.
    کلیدواژگان: بافت، سیستم اطلاعات مکانی بافت آگاه، گردشگری، مراغه
  • محسن بختیاری *، علی درویشی بلورانی، عطاءالله عبداللهی کاکرودی، کاظم رنگزن صفحات 87-99
    سنجش از دور عرصه ی نوینی را در پایش و مدلسازی متغیرها و پارامترهای محیطی، در سطوحی متفاوت گشوده است به طوری که می تواند به عنوان یک زمینه تحقیقاتی و عملیاتی مناسب برای پیش بینی و مقابله با اثرات مخرب بحران های زیست محیطی، قلمداد گردد. در این میان، قابلیت های سنجنده یMODIS به لحاظ ارائه محصولات متنوع جهت تخمین پارامترهای محیطی، بیشتر از هر ابزار دورکاوی دیگر، نمود یافته است. در تحقیق حاضر از محصولات سنجنده MODIS برای معرفی شاخص نرمال شده سلامت زیست محیطی، NHEI، همراه با روندیابی تغییرات زمانی و بررسی ارتباط آن با کانون های گرد و غبار غرب آسیا در دهه ی اخیر، استفاده شده است. این شاخص، به صورت توامان رفتارهای دمای سطحی و پوشش گیاهی را مدلسازی می کند. به علت همبستگی بالای نتایج حاصل از شاخص توسعه داده شده با کانون های گرد و غبار، از آن می توان به عنوان مبنایی برای مدلسازی و روندیابی رفتار کانون های گرد و غبار بهره برد. NHEI برای سال های 2002 تا 2013 توسعه یافت، سپس روند تغییرات آن به کمک فرآیند روندیابی خطی آشکارسازی شد و ارتباط آن با کانون های گرد و غبار ارزیابی گردید. از آنجایی که NHEI روند تغییرات عناصرکلیدی دما، پوشش گیاهی و رطوبت را به صورت توام نشان می دهد، نتایج روندیابی سلامت زیست محیطی حکایت از کاهش کلی شدت و گستره آن در محدوده ی مورد مطالعه دارد. در حالی که توزیع نواحی بحرانی به سوی پراکندگی بیشتر میل نموده است. این مطالعه بر قابلیت های NHEI در پایش و مدلسازی متغیرهای محیطی در ارتباط با طوفان های گرد و غبار، تاکید می ورزد به طوری که متوسط NHEI کانون های گرد و غبار به طور معنی داری کمتر از متوسط NHEI محدوده مطالعاتی بود، بنابراین نتایج این مطالعه می تواند افق جدیدی در حوزه ی برآورد پارامترهای محیطی به کمک طراحی شاخص های سنجش از دوری نوین را بگشاید.
    کلیدواژگان: محصولاتMODIS، شاخص نرمال شده سلامت زیست محیطی، روندیابی، کانون های گرد و غبار
  • حیدر لطفی *، حسین موسی زاده صفحات 101-117
    زلزله از پدیدهای طبیعی است که در طول تاریخ حیات بشر همواره انسان را به وحشت انداخته و باعث تخریب شهرها و روستاهای زیاد همراه با تلفات انسانی شدید شده است.زمین لرزه، لرزش و جنبش شدید و یا خفیف قشر کره زمین است که به نقصان درجه حرارت مواد مرکزی و ایجاد چین خوردگی و فشار منجرشده و یا در اثر انفجارهای آتشفشانی بوقوع می پیوندد. لذا مسئولان موظف هستند بکوشند با این پدیده و راه های موثر در کاهش تلفات و خسارات ناشی از آن آشنا گردند. هدف پژوهش حاضر شناسایی نقاط لرزه خیز کشور ایران با توجه به تغییرات دمایی و رخداد های لرزه ای ثبت شده می باشد. روش پژوهش،باتوجهبهماهیتمسئلهوموضوعموردبررسی،ازنوعتوصیفی-تحلیلیاست واز نوع مطالعات کاربردی با تاکید بر روش های کمی است. در این تحقیق از تصاویر سنجنده مودیس (محصول MOD11A1) ماهواره ترا برای سال های2000 تا 2018 استفاده شده است. این تصاویر قدرت تفکیک یک کیلومتر دارند و بنابراین هر پیکسل از این تصاویر مساحتی در حدود100 هکتار زمین را شامل می شود. همچنین به منظور پهنه بندی زمین لرزه ها از روش های درونیابی زمین آمار استفاده گردید، تمامی فرایندها و تجزیه تحلیل داده ها در محیطGIS انجام شده است. با توجه به نقشه نهایی بدست آمده و بررسی تغییرات دمایی و رخدادهای بوقوع پیوسته، قسمت های مربوط به نیمه جنوبی و جنوب غربی کشور (بوشهر، کرمانشاه، هرمزگان، خوزستان، ایلام) در معرض آسیب بسیار زیاد قراردارند. همچنین عرض های مربوط به نیمه مرکزی وجنوب شرقی کشور (کرمان، سیستان و بلوچستان، جنوب غربی خراسان جنوبی، شرق یزد) در معرض آسیب متوسط تا زیاد و همچنین نیمه شمالی کشور (گلستان، مازندران، گیلان، اردبیل) در پهنه آسیب کم قرار گرفته اند.
    کلیدواژگان: زلزله، آسیب پذیری، تغییرات دمایی، رخدادهای لرزه ای، تصاویرمودیسMOD11A1، GIS، ایران
  • زهرا بهاری سجهرودی *، رضا آقاطاهر، محسن جعفری صفحات 119-128
    زبری زمین متغیر مهمی است که در علوم نجوم و زمین استفاده می شود. تعریف منحصربه فردی برای آن وجود ندارد. آن را می توان متغیری جهت بیان تغییرپذیری سطح زمین در یک مقیاس معین تعریف نمود. محاسبه ی زبری از اهمیت زیادی برخوردار است و مبنای بسیاری از تصمیم گیری ها می باشد. بررسی کیفی قسمت های مختلف یک محدوده ای از زمین از نظر زبری و تغییرات ارتفاعی با در نظر گرفتن تمامی جوانب، نیازمند پردازش ها و مقایسه های متفاوتی می باشد، از طرف دیگر حجم این پردازش ها بسیار بالا و زمان بر است. در مقاله حاضر یک سامانه تصمیم گیری مکانی جهت تعیین خودکار نواحی مطلوب کاربر و بررسی همه جانبه ی منطقه مورد نظر با استفاده از داده های مدل ارتفاعی رقومی، طراحی و پیاده سازی گردید. شاخص های مورداستفاده جهت محاسبه ی زبری هر منطقه در این سامانه، عبارتند از: سیگما تی، سیگمازد و هندسه فرکتالی. در توسعه این سامانه از تلفیق شاخص های نامبرده با روش های مبتنی بر سامانه حامی تصمیم گیری مکانی استفاده گردید. این سامانهاطلاعات آماری مربوط به پچ های[1] متعدد در محدوده تعیین شده از مدل ارتفاعی رقومی مورد نظر را استخراج کرده و با رتبه بندی و کلاسه بندی پچ ها براساس معیارهای تعیین شده، به انتخاب پچ های مورد نظر کمک فراوانی می کند. این سامانه برای محدوده های متفاوتی از ایران تست و قابلیت های آن مورد ارزیابی قرار گرفت.
    [1]- در این مقاله پچ عبارت است از تکه هایی از زمین که مشخصات آماری مربوط به آنها استخراج می شودو می تواند ابعاد متفاوتی داشته باشد.
    کلیدواژگان: زبری، تحلیل های مکانی، سامانه حامی تصمیم گیری، رتبه بندی، کلاسه بندی
  • کامران کریمی، غلامرضا زهتابیان، مرزبان فرامرزی، حسن خسروی * صفحات 129-140
    دردهه های اخیر،تغییرات سریع کاربری اراضی به ویژه در مناطق دارای اکوسیستم حساس باپیامد تخریب منابع طبیعی همراه بوده است. متاسفانه بخش مهمی از این تغییرات، غیراصولی و خارج از برنامه بوده که اطلاع از این تغییرات برای برنامه ریزان اهمیت بسزایی دارد. دراین مطالعه تغییرات پوشش اراضی در دو دوره قبل و بعد از بهره برداری از شبکه های آبیاری سد کرخه به دشت عباس در استان ایلام مورد ارزیابی قرار گرفت. از تصاویر سنجنده های لندست TM، ETM+ و OLI به ترتیب برای سال های 1368، 1382 و 1392 و همچنین نقشه هایتوپوگرافی و پوشش منطقه استفاده گردید. تصاویر هر سه مقطع زمانی به پنج طبقه کاربری مرتع، اراضی کشاورزی، اراضی مسکونی، بستر رودخانه و اراضی بایر و تپه ماهور طبقه بندی شدند.همچنین به منظور تعیین دقیق تر تغییرات افزایشی کاهشی مساحت ها برای دو دوره بدست آمد. نتایج نشان داد که در طول دو دوره کاربری بایر و تپه ماهور بیشترین مساحت از منطقه را در بر گرفته است، به طوریکه دوره اول 1/12344 هکتار و دوره دوم 5/17370 هکتار بوده است. همچنین طی دو دوره طبقه مرتع با تخریب مواجه بوده با این تفاوت که در دوره دوم، 3/14% بیشتر از دوره اول بوده است. همچنین در دوره دومبه دلیل بهره برداری کشاورزان از سیستم های آبیاری تغییرات کاربری ها بیشتر به سمت تبدیل به کاربری کشاورزی بوده است، به طوری که طی 10 سال 8/3671 هکتار 550% به این اراضی افزوده شده است. بیشترین تبدیل کاربری به کاربری کشاورزی مربوط به کاربری اراضی بایر و تپه ماهور بوده است. این اراضی به علت اینکه در بین اراضی کشاورزی و در فاصله کمی نسبت به سیستم های آبیاری واقع گردیده اند، توسط ساکنان منطقه بیشتر دستخوش تغییر قرار گرفته اند. بامشخصنمودنحریمبرایاراضی کشاورزی می توان تا حدود زیادی از تغییرات کاربری اراضی در دشت مذکور جلوگیری نمود.
    کلیدواژگان: کاربری اراضی، آشکارسازی تغییرات، ضریب کاپا، سدکرخه، دشت عباس
  • امیرمهدی امامی زاده مهابادی *، کامران لاری، مجتبی ذوالجودی صفحات 141-152
    رسوب گذاری در کانال های دسترسی بنادر یک مشکل عمده برای مسئولان بندر و همچنین شناورهایی است که در این کانال ها تردد می نمایند.این پدیده علاوه بر تحمیل هزینه های سنگین به بندر، خطراتی را در این بخش حیاتی از بندر برای شناورها بوجود می آورد. در این تحقیق به بررسی و برآورد نرخ و حجم رسوب گذاری در کانال دسترسی بندر امام خمینی (ره) بر اساس اطلاعات میدانی پرداخته شده است. در پژوهش حاضر، تحلیل هایی در مورد وضعیت جغرافیایی از قبیل تراز بستر، تحلیل سری های زمانی موج و جزر و مد (به عنوان جریان) در منطقه توسط نرم افزار مایک 21 انجام و مدلسازی مناسبی ارائه شد.جهت بررسی حجم و نرخ رسوب گذاری از روش های هیدروگرافی، تئوری بایکر و مدلسازی توسط مایک21 استفاده گردید. الگوی هیدرودینامیک جریان و انتقال رسوب با استفاده از روش های مهندسی معتبر انجام شده است. همزمان مجموعه اطلاعات و داده های کتابخانه ای و نتایج داده های میدانی موجود، جمع آوری و تجزیه و تحلیل گردیده و نتایج بدست آمده از روش های مختلف (هیدروگرافی،بایکر و مایک21) کالیبره شدند. براساس نتایج حاصله و بررسی نقشه های هیدروگرافی مقدار واقعی رسوب گذاری در کانال/s/m 000078m3/0بدست آمد و باتوجه به اینکه روش هیدروگرافی معیاری برای کار و محاسبات به روش های دیگر در نظر گرفته شد، درصد خطای نتایج حاصل از محاسبات بایکر 12% و مدلسازی مایک حدود 20% محاسبه گردید. بر این اساس ضرائب بدون بعد 88/0= برای تئوری بایکر و 2/1= برای نتایج حاصل از محاسبات توسط مایک21 بدست آمد که نشان دهنده دقت خوبی بود. براساس نتایج حاصله می توان شیوه بهینه لایروبی و تغییرات مورفولیژیکی منطقه را بر اساس مدل های حاصله بدست آورد.
    کلیدواژگان: رسوبگذاری، بایکر، مایک 21، بندرامام خمینی(ره)، کانال دسترسی، هیدروگرافی
  • مریم ارجمند، علیرضا راشکی *، حسین سرگزی صفحات 153-168
    منطقه جازموریان واقع در جنوب شرقی ایران- بین دو استان کرمان و سیستان و بلوچستان ایران، هم اکنون به دلیل خشکسالی و سدسازی های متعدد، کاملا خشک و تبدیل به بیابان شده است. این منطقه یکی از مناطق کلیدی تولید گرد و غبار کشور است، اما تاکنون مطالعات محدودی در این منطقه بخصوص در زمینه گرد و غبار صورت گرفته است. به منظور بررسی گرد و غبار در این منطقه از داده های ماهواره ای شامل شاخص گرد و غبار AAI بدست آمده از سنجنده هایTOMS_N7 (1978-1993) ، EP (1996-2005)TOMS_ و OMI (2005-2014) و شاخص عمق نوری گرد و غبار AODحاصل سنجنده های MISR (2000- 2013) و MODIS (2000-2014) استفاده گردید. نمودار تغییرات زمانی شاخص ها در منطقه جازموریان و نقشه های پهنه بندی رخدادهای گرد و غبار برای جنوب شرق ایران تهیه شد. چند نقطه در جنوب شرق ایران به عنوان کانون تولید گرد و غبار؛ شامل: زابل، منطقه ای در پاکستان نزدیک به مرز ایران، سواحل مکران (خلیج گواتر) و منطقه جازموریان شناسایی گردید. با توجه به تغییرات سالانه شاخص ها می توان چندین سال یا دوره را به عنوان دوره های اوج طوفان گرد و غبار در منطقه شناسایی کرد، 1363 (شروع رخداد طوفان های گرد و غبار)، 1370، 1382-1383، 1387 و1391. به طور کلی روند صعودی در مقادیر شاخص ها را می توان در نتیجه ساخت سدهای متعدد بر سر راه رودهای تغذیه کننده جازموریان و در نتیجه خشک شدن تدریجی آن دانست و افزایش های ناگهانی در مقادیر می تواند در نتیجه وقوع خشکسالی ها باشد.عمده وقایع گرد و غبار در منطقه جازموریان در دو فصل بهار و تابستان اتفاق می افتد و به ترتیب در فصل زمستان و پاییز از شدت آن کاسته می شود. بنابراین فعالیت گرد و غبار در چهار ماه می، ژوئن، ژولای و آگوست شدید و در چهار ماه نوامبر، دسامبر، ژانویه و فوریه ضعیف تر از سایر ماه ها می باشد.
    کلیدواژگان: گرد و غبار، شاخص AAI و AOD، جازموریان، جنوب
  • علی اکبر رسولی، علی محمد خورشید دوست، مجتبی فخاری واحد * صفحات 169-178
    آذرخش یکی از جذاب ترین پدیده های آب و هوایی است که هنوز به طور کامل درک نشده استودر انواع ابر به زمین، ابر به ابر و درون ابر رخ می دهد. آذرخش نوع ابر به زمین از جمله مهمترین علل مرگ و میر ناشی از عوامل آب و هوایی استوعلاوه بر خسارات مالی، سالانه در حدود 2000 نفر بر اثر این پدیده جان خود را از دست می دهند. در این پژوهش با استفاده از داده های سنجنده LIS پراکنش، تراکم و چرخه روزانه رعد و برق ها بررسی شد و رابطه فراوانی رعد و برق ها با ارتفاع از تراز دریا مورد آزمون قرار گرفت. برای بررسی توزیع آماری داده ها از شاخص نزدیکترین همسایه و برای نشان دادن توزیع فضایی داده ها از تابع تراکم کرنل در نرم افزارGIS استفاده شد. رابطه رعد و برق ها با ارتفاع، به روش گرافیکی و رگرسیون چند جمله ای بررسی شد. نتایج این پژوهش نشان داد که بیشینه فراوانی رعد و برق ها در ماه های مارس تا آگوست رخ می دهد. همچنین بررسی تغییرات روزانه نشان داد که از ساعت 13تا 16به وقت محلی فعالیت های رعد و برقی به صورت معنی داری افزایش می یابد. نتایج شاخص های نزدیکترین همسایه و تابع تراکم کرنل نشان داد که پراکنش داده ها از الگوی خوشه ایپیروی می کندوپراکنش فضایی داده ها طوری است که در دامنه های جنوبی ناهمواری های جنوبی این منطقه فراوانی رعد و برق ها بیشتر است. رابطه فراوانی رعد و برق ها با ارتفاع نیز نشان داد که بیشینه فراوانی رعد و برق ها در دامنه های جنوبی و قبل از رسیدن به قله اصلی و در ارتفاع بین 700 تا 1200 متر قرار دارد.
    کلیدواژگان: رعد و برق، LIS، تابع تراکم کرنل، جنوب شرق ایران
  • مهدیه سلطانی گردفرامرزی *، غلامعلی مظفری، شهاب شفیعی صفحات 179-199
    در سال های اخیر تغییرات جهانی اقلیمی در بسیاری از مناطق کشور خصوصا فلات مرکزی ایران منجر به تشدید پدیده خشکسالی شده است. دشت یزد- اردکان در استان یزد نیز از این امر مستثنی نبوده و تکرار این پدیده منجر به بروز تغییراتی در کیفیت و کمیت منابع آب موجود دشت که عمدتا چاه های آب زیرزمینی هستند؛ گردیده است. هدف از انجام این پژوهش بررسی تاثیر خشکسالی های دودهه اخیر بر شوری آب استحصالی از چاه های آب زیرزمینی منطقه می باشد. برای این کار از داده های هواشناسی دشت یزد- اردکان در دو دوره زمانی، بارش بلند مدت 7 ایستگاه (1391- 1346)و بارش کوتاه مدت41 ایستگاه (1391 - 1375) استفاده شده است. نتایج این مطالعه در ارزیابی مدل های واریوگرامی خشکسالی ها بهترین مدل را،مدل کروی و گوسین در خشکسالی و شوری و همچنین با توجه به روش زمین آماری بهترین مدل برونیابی را، کریجینگ و کوکریجینگ تشخیص داده است. در تحلیل همبستگی باهر سه آماره پیرسون، منکندال و اسپرمن بین بارش (spi) وشوری بر مبنای نمره z روند منفی به همراه همبستگی معکوس مشاهده شده، که در هیچکدام سطح معنی دار مشاهده نمی شود. وجود همبستگی قوی بین این دو پارامتربا تاخیر یک سال از نتایج دیگر این پژوهش بوده است. به وسیله نرم افزار +GS و GIS انتخاب بهترین مدل واریوگرامی، نقشه های خشکسالی و شوری آب زیرزمینی و نقشه تغییرات شوری نیز ترسیم گردید. به طور کلی در اکثر ایستگاه ها با روند منفی بارش، روند مثبت شوری آب زیرزمینی مشاهده می شود و همچنین کیفیت آب زیرزمینی در مناطقی که بیشتر مورد هجمه خشکسالی قرارداشته است شدیدتر تغییر یافته و شوری آن نیز بیشتر شده است.
    کلیدواژگان: خشکسالی، آب زیرزمینی، شوری، زمین آمار، سیستم اطلاعات جغرافیایی (GIS)، دشت یزد، اردکان
  • محسن پورخسروانی *، سیده الهام موسوی صفحات 201-212
    توزیع جغرافیایی مخاطرات طبیعی که به کشته شدن تعداد زیادی از مردم و ویرانی جوامع انسانی می انجامد بر مکان گزینی نامناسب نواحی و رشد بی برنامه منطبق می باشد. رشد بی رویه شهرها و خزش مناطق شهری بر بستر طبیعی بدون توجه به خطرات طبیعی لزوم توجه به شناخت شرایط ژئومورفیک منطقه، مخاطرات محیطی و برنامه ریزی شهری در تعیین حریم امن و پایدار توسعه شهرها را می طلبد. در این تحقیق با مطالعه فرآیندهای ژئومورفولوژیک و مخاطرات محیطی در محدوده مورد مطالعهو با استفاده از مدل های SAW،Dematel وAHP سعی شده است که فرصت ها و محدودیت های موجود در جهات مختلف توسعه شهرهای دالکی- وحدتیه مشخص و در نهایت مناسب ترین محور برای توسعه آینده شهر تعیین شود. هر چند دو مدل Dematel و AHP هر دو به مقایسه زوجی هر عنصر نسبت به سایر پارامترها می پردازد، اما مدلAHP به دلیل مقایسه وزن طبقات هر معیار بر اساس ترجیح یک طبقه نسبت به تمام طبقات آن معیار، آن هم بدون تاثیرگذاری و یا تاثیرپذیری نتایج بهتری را ارائه می دهد. همچنین مدل SAW نیز با تعیین مستقیم اوازن نتایجی را پیشنهاد می نماید. از این رو با توجه به تضاد نتایج نهایی وزن دهی پارامترها؛ در این نوشتار به ادغام اوازن با استفاده از روش میانگین رتبه ها پرداخته شد. مطابق با این روش پارامتر مواد مادری با میانگین رتبه33/1 ارجح ترین پارامتر و شیب و سطوح اراضی با میانگین رتبه 76/3 دارای کمترین ارجحیت در وزن دهی عوامل می باشد. مطابق با این بررسی ها اراضی جنوب شرق، شمال، شمال شرق و دامنه های شرقی مناسب ترین جهات برای توسعه فیزیکی دو شهر دالکی و وحدتیه می باشد.
    کلیدواژگان: ژئومورفولوژی، توسعه فیزیکی، مخاطرات محیطی، ارزیابی چندمعیاره، دالکی، وحدتیه
  • علیرضا سلیمانی، احمد آفتاب *، علی مجنونی توتاخانه صفحات 213-227
    در کشور ایران مناطق مرزی به دلیل وجود طیف گسترده ای از تهدیدات بالقوه و بالفعل کانون های بحران در کشورهای همسایه، لزوم اقدامات و تدابیر موثر دفاعی و مقابله با این تهدیدات آشکار است تا از این طریق بتوان ضمن تامین امنیت، شرایط را جهت رشد و توسعه اقتصادی روستاهای فراهم ساخت. در این راستا هدف پژوهش حاضر، تحلیل ساختار فضایی سکونتگاه های روستایی در نواحی مرزی ایران و ترکیه با تاکید بر پدافند غیرعامل می باشد. نوع پژوهش کاربردی بوده و روش تحقیق آن توصیفی تحلیلی می باشد. در این ارتباط 8 معیار اصلی (منابع آب، مخاطرات طبیعی، شکل زمین، ملاحظات امنیتی، اقلیم، ملاحظات جمعیتی، دسترسی به امکانات ، جنس زمین) با 17 زیرمعیار در قالب مدلANP در رویکردی تلفیقی با سیستم اطلاعات جغرافیایی مورد تحلیل قرار گرفتند، نتایج حاصل از پژوهش، پهنه بندی محدوده مورد مطالعه بر اساس آسیب پذیری در قالب پنج طبقه خیلی کم تا خیلی زیاد می باشد. یافته های تحقیق نشان می دهد که از 1259 روستای واقع در محدوده مورد مطالعه 29 درصد از آنها با جمعیتی بالغ بر 150213 (3/26 درصد) در محدوده آسیب پذیری خیلی زیاد و زیاد قرار گرفته اند. این درحالی است که در محدوه آسیب پذیری خیلی کم از نظر قابلیت پدافندی 299 روستا با 31 درصد از جمعیت قرار دارد. نتایج نشان می دهد که ملاحظات امنیتی با امتیاز 349/0 بیشترین اهمیت و تاثیر را در تحلیل سکونتگاه های روستایی نواحی مرزی ایران و ترکیه از نظر پدافند غیرعامل دارد. در مرتبه های بعد ملاحظات جمعیتی با امتیاز 232/0 و مخاطرات محیطی با امتیاز 150/0 از نظر اهمیت قرار دارند. در این میان، جنس زمین و منابع آب به ترتیب با میزان اهمیت 019/0 و 026/0 کم اهمیت ترین می باشند.
    کلیدواژگان: تحلیل فصایی، سکونتگاه های روستایی، پدافند غیرعامل، امنیت، نواحی مرزی ایران و ترکیه
  • علیرضا دربان آستانه، سجاد فردوسی *، حمیدرضا شاه محمدی صفحات 229-239
    گردشگری دریایی یکی از جذاب ترین و پرطرفدارترین شاخه های گردشگری به شمار می آید که در دهه های اخیر رونق بسیاری یافته و بخش قابل توجهی از اقتصاد گردشگری را به خود اختصاص داده است. در این میان کشور ایران با وجود برخورداری از مرزهای ساحلی وسیع در شمال و جنوب تاکنون نتوانسته خدمات مطلوبی را در ارتباط با گردشگری دریایی به گردشگران ارائه نماید. از جمله اقداماتی که می توان در این زمینه انجام داد احداث سایت های گردشگری دریایی در مناطق ساحلی است. به منظور مکانیابی چنین سایت هایی در نظر گرفتن معیارهایی بدین شرح ضروری است: فاصله از دریا، دید نسبت به دریا، آفتاب گیری، کاربری اراضی، فاصله از مخاطرات طبیعی همچون گسل، سیلاب، فرسایش، فاصله از سکونتگاه ها، فاصله از رودخانه و دریاچه، فاصله از شبکه معابر، فاصله از مناطق حفاظت شده و درصد شیب. بر این اساس پژوهش حاضر به روش توصیفی- تحلیلی و با هدف شناسایی مطلوب ترین نقاط به منظور احداث سایت گردشگری دریایی تدوین گردیده است. اطلاعاتموردنیاز به روش کتابخانه ایجمع آوری گردیده است. جهت وزن دهی به معیارهای مورد بررسی از طریق نظرخواهی از 32 کارشناس و متخصص و از روش AHP استفاده شده است. پس از تعین وزن هر یک از معیارها، لایه های اطلاعاتی هر یک از معیارها در محیط GIS ایجاد گردیده و در نهایت با روی هم گذاری لایه های اطلاعاتی، مناسب ترین مکان ها جهت ایجاد سایت گردشگری دریایی معرفی گردیده است. بر این اساس چهار محدوده در شهرستان تنکابن به منظور جانمایی سایت گردشگری دریایی نسبت به سایر نقاط، مطلوب تشخیص داده شده است. بنابراین برنامه ریزی مناسب برای ایجاد سایت های گردشگری دریایی در مکان های پیشنهاد شده به ترتیب اولویت، توسعه پایدار گردشگری و متقابلا توسعه اقتصادی منطقه را به همراه خواهد داشت.
    کلیدواژگان: گردشگری دریایی، مکانیابی، دریای خزر، GIS، AHP
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  • Yasin Kazemi, Saeid Hamzeh *, Seyed Kazem Alavipanah, Bahram Bahrambeygi Pages 5-20
    Introduction
    Faults are fractures in the earth’s crust that has the ability to move. Faults are one of the most important geological structures, and since they have paths for emersion of heat from the lower parts of the earth’s crust to the surface, can be considered as one of the essential reasons of potential of geothermal energy. Geothermal energy is one of the major sources of renewable energy and compatible with the environment, which if properly utilized and bases on environmental parameters, can play an important role in the energy balance of the country and the goals of sustainable development. There are many methods that can be used to identify potential geothermal, one of which is remote sensing that is part of new technologies, and it is also cost-effective. Among the various methods of remote sensing for exploration of geothermal resources, thermal remote sensing has unique advantages. Thermal infrared remote sensing is an effective method to identify the Earth’s surface temperature anomalies whose combination with the analysis of geological and understanding of geothermal mechanism, can be an appropriate approach for exploration of geothermal areas.
    Materials And Methods
    Data used in this study included images of Landsat-8, geological map of the region and the layer of active faults as well. Images were taken on February 2015, and the reason for selecting this time of year for image processing is to reduce the impacts of solar radiation on the earth’s surface temperature and therefore less impact on the heat causes by faults. The study area of this research is the Shahdad county of Kerman city. Two faults of Shahdad and Nayband are in this region. In this research, the method of Single Chanel is used to retrieve the surface temperature. The software used in this study include ENVI5.3, ERDAS Imagine 2014, and ArcGIS 10.3. After the calculation of the Earth’s surface temperature by Landsat 8, the thermal behavior of the faults was analyzed.
    Results And Discussion
    In this part of the study, two transversal profiles with an approximate length of 12 km were taken for each one of the faults, from the surface temperature map of the region. By examining the graphs of the temperature profiles, it was found that temperature changes along the profile increase with the approach to the location of the fault’s surface outcrop. The heat accumulation along the Nayband fault corresponds to the closeness to the fault central zone, but this correspondence has been less for the Shahdad fault. Also, by creating a 6 kilometer buffer around the faults, it was observed that the average temperature of the pixels of this buffer is about two degrees higher than the average temperature of pixels of the entire region.
    Conclusion
    Investigating the possibility of instrumental use of the Landsat-8 satellite’s analyzing capability of thermal data to determine the position of the fault based on the thermal anomalies created around the central zone of the faults in the present research showed that LST calculation from the aforementioned data is considered as an appropriate method for extracting the linear anomalies and tracking the possible fault zones. Also, the temperature processing on the areas surrounding the Shahdad fault and the southern part of the Nayband fault and the presence of the thermal aggregates associated with the aforementioned faults are considered as the land index areas. These thermal aggregates in transections created on the faults indicate that the amount of LST increases clearly with approaching the location of the central zone of the above-mentioned faults on the earth’s surface. Linear thermal accumulations around the faults are the effects of the superficial and deep causes, so that sometimes the basement faults of the lava exit area have been the constituent of the surface lithology of an area at the time of the formation, which are younger and have less weathering and higher capacity for absorbing the sunlight, while approaching the central zone of the faults as the eruption openings of the volcanic rocks. On the other hand, due to the depth of the faults and their depth’s access to the hot material forming the asthenosphere part beneath the earth’s crust, the geothermal gradient in the central zones of these fault is higher than the surrounding areas. Considering the lack of introducing the volcanic rocks in the geologic map of the study area, it can be concluded that the linear thermal anomaly around the existing faults in the area is mainly associated with the deep heat sources and it is less likely to be associated with the absorption of the surface heat. Regarding the evident increase in temperature on the isothermal diagrams close to the central zone of the faults in the study area, two areas with the highest slope of increasing temperature along the central zone of the faults were identified and introduced as the possible geothermal potentials for more precise studies and future surveys. These two areas are located 45 kilometers southeast and about 15 kilometers northwest of the town of Shahdad.
    Keywords: Thermal remote sensing, LST, Geothermal resource, Thermal anomalies, Shahdad fault, Nayband fault
  • Behnam Tashayo *, Mohammad Sharif Pages 21-35
    Introduction
    With the developments in navigation, positioning, and tracking technologies, a large amount of moving point data (e.g., human, vehicle, animal) have been produced. Through moving an object in the course of time, a sequence of its position is recorded which is known as trajectory. Studying the behaviors of point objects and analyzing their trajectories have recently received great attentions among researchers in different fields of science, especially in geographic information science. Such studies contribute to better understanding of movement-behavior patterns of moving objects. Data mining, as one of the main approaches in geographic knowledge discovery, is normally used in moving databases to extract information from moving point objects’ trajectories. Analyzing the similarity of trajectories as one of the frequently used approaches in geographic data mining, is of great importance, which is normally performed by distance functions.
    The way an object moves is highly influenced from the condition and situation (known as context) where movement takes place. Therefore, merely analyzing trajectories from their spatiotemporal dimension may not clearly reflect the conditions and situations (contexts) during the move, and may lead to unrealistic results. Accordingly, most of the present distance functions are only able to measure the similarity of trajectories at spatial and spatiotemporal dimensions and neglect the underlying context during the move. Therefore, developing a new trajectory similarity measure approach, capable of handling a wide range of context information in conjunction with spatiotemporal dimension becomes crucial.
    Materials and Methods
    According to the complexity and variety in the moving objects’ datasets, especially in their context parameters, in this research, a fuzzy model is developed which is able to exploit a wide range of internal and external context information in similarity measure process of multi-length trajectories. Specifically, a fuzzy inference system (FIS) is used for measuring the similarity between trajectories based on qualitative and quantitative context information. To enhance the effectiveness of the system, a subjective hierarchical fuzzy inference system (HFIS) is designed and the membership functions and rules are generated and adjusted based on learning. The HFIS controls the rules by dividing a FIS into several simple sub-systems that are hierarchically connected to each other. The Multi-Objective Particle Swarm Optimization (MOPSO) algorithm is used for defining and adjusting the FIS.
    The performance of the system is assessed by applying it on real trajectories of pedestrians’ and cyclists’ datasets in the Central Park of Manhattan, New York, USA, while accounting contextual information. The movement parameters and context information were recorded in qualitative and quantitative formats. Two types of context information are used: 1) internal context (i.e., all of the properties that directly relate to the moving object, such as eagerness), and 2) external context (i.e., any factor that extrinsically influences the process of movement, such as slope). According to the nature of data, four models of spatial, spatiotemporal, spatiotemporal-internal context, and spatiotemporal-internal-external context are applied on the dataset to see the added value of each parameter.
    Results and Discussion
    The achievements of the implementations can be discussed from two main perspectives: 1) system performance, and 2) similarity results. From the system performance aspect, the control surface plots indicate the consistency of the rules in the developed fuzzy inference systems. In addition, the Pareto diagrams for both pedestrians’ and cyclists’ models cover the Pareto fronts in all four models in an appropriate manner.
    From the similarity results aspect that are shown in boxplots, the commonalities between both pedestrians’ and cyclists’ trajectories are very high at the spatial dimension in the first model, while by adding the temporal dimension as the second model, the similarity range at the spatiotemporal dimension increases. This issue is directly related to the traversed paths and the elapsed times of the moving objects. By importing the internal contexts (i.e., speed, direction, length, eagerness) as the third model, the similarity range again increases but the median decreases. However, the distribution in the pedestrians’ similarity values is much more than the cyclists’ values. The fourth model is composed of all the previous parameters plus the external contexts (i.e., path difficulty and slope). The same as previous trends, the similarity range increases but the median decreases. Although the number of trajectories that share common characteristics are low when taking into account all the spatial, temporal, internal contexts, and external contexts in the implementation, the results become much more realistic and close to reality for both datasets.
    In addition, to assess the influence of the internal and external contexts on the similarity output, a one-way analysis of variance (ANOVA) test, with a 95% confidence level, is applied on the results. Furthermore, a number of sensitivity analyses are applied on the datasets. The outcomes demonstrate meaningful influence of contexts on the similarity results of trajectories.
    Conclusion
    In this research a novel approach based on fuzzy systems is developed for multi-dimensional similarity measure of trajectories while accounting both internal and external context information. This approach enhances the previous similarity functions that only use spatial and temporal data. The developed models were applied on two real trajectory datasets, which were capable of handling both quantitative and qualitative information. The results indicate the effectiveness of the proposed context-aware similarity measure approach in revealing the commonalities between trajectories in multi dimensions.
    Keywords: Trajectory, Similarity measure, Context, awareness, HFIS, Multi, objective optimization
  • Ali Kalantari Oskouei *, Mahdi Saber Khoshemehr Pages 37-55
    Introduction
    Data sharing is one of the key issues in the success of Spatial Data Infrastructure (SDI). Data sharing can prevent the repeated production of spatial data by various organizations and institutions, and provide the reduction of the costs, prevention of the resource losses, helping the economic development and using the capabilities of spatial data in processes of decision-making. But, evidences suggest that the realization of the spatial data sharing has always faced numerous challenges and problems, and that the SDI development goals will not be achieved without solving them. Therefore, the main objective of this research is to provide a strategy for identifying and prioritizing the sharing of spatial data in the country.
    Materials and Methods
    The framework of the research is based on surveying, the concept of risk, and the use of a fuzzy inference system. In order to objectify this framework, a case study was conducted with the participation of 19 organizations in East Azarbaijan province. At first, various sources were reviewed and the 25 probabilistic sharing challenges were identified. Then, with the help of a questionnaire, experts’ viewpoints regarding the probability of the occurrence and severity of the impacts of the challenges were investigated. The questionnaire consists of two parts. The first part focuses on the demographic information of the experts such as affiliation, years of experience, and academic degree, which were used to determine the experts’ importance weight. The second section measures the probability and the impact intensity of each identified challenge. To measure the factors of probability and impact intensity, a five level verbal rating scale including, very high, high, medium, low and very low (as verbal terms) was used to maintain the balance between simplicity and comprehensiveness. In the next stage, a fuzzy inference system, with two inputs and one output, 25 fuzzy rules, Guassian membership functions and the field inference engine were developed to process the views of the experts and to calculate the fuzzy scores of each of the challenges using MatlabR software. Having determined the sharing challenges scores, a cluster analysis was carried out to divide them based on the score related to the groups (clusters), so that, the challenges inside a cluster are very similar (but not identical) to one another but very different from the challenges in other clusters. Since there is no need to specify the numbers of clusters in hierarchical methods in advance, the hierarchical method was used as a clustering technique to group the challenges. Then, the results were evaluated by a number of knowledgeable experts.
    Results and Discussion
    According to the findings, the most important challenges which had the highest scores and were also in the same cluster, include: lack of a Geoportal for searching, access and evaluation, lost problems or metadata, lack of coordination among different organizations for spatial data sharing, fear of disclosing of organizational spatial data and information, the lack of up-to-date spatial data and information, the tendency to parallel work (the lack of investigation of other organizations for spatial data and information needed by the organization) and the lack of specialist in spatial data and sharing the information. Moreover, 25 challenges of spatial data were categorized into five homogenous groups (clusters) by applying a hierarchical cluster analysis. Based on the results, the overall geometric mean value of the 25 challenges of the spatial data and information sharing was calculated as 62.76% that shows the existence of the important challenges in the realization and implementation of the spatial data sharing and SDI initiatives in organizations. Analyzing the results with regard to the two types of sharing challenges revealed that the organizational challenges with a geometric mean of 55/56% were more important than the technical challenges with a geometric mean of 44/44%. These results may mean that, in order to overcome the organizational challenges, more time and efforts have to be taken into consideration in the planning and development of SDI compared to the technical challenges.
    Conclusion
    It seems that there is no accurate and complete picture of the concept of the spatial data sharing in the majority of the organizations, and it is often interpreted as putting spatial data and information of the organization in the hands of others. However, a significant part of the sharing issue is associated with the metadata sharing that prevents the repeated works and spending unnecessary credits of the organizations, and make the available data to be accessible with spatial services in different formats after an agreement between data providers and consumers, and to be used in decision making processes. The information gap in this regard is very tangible in the organizations, nevertheless, it would be possible to change the views and behaviors of individuals and organizations by creating capacity, and eventually to be hopeful that the willingness of organizations to participate in data sharing improve. Finally, the following recommendations were suggested in order to improve the status of the data sharing: individual and organizational attitude changes towards the issue of data sharing, increasing technical knowledge and empowering organizations in spatial technologies and clarifying the benefits of spatial data sharing and its socioeconomic roles in society, specifying the leader organization and forcing organizations to create standard spatial databases and metadata.
    Keywords: Coordination, Geoportal, Metadata, Obstacles, Spatial Data Infrastructure, Standard
  • Saeideh Zamani, Majid Rahimzadegan * Pages 57-69
    Introduction
    Evaporation from the lakes behind the dams and freshwater lakes is one of the most important parameters in water resource losses. Therefore, zoning evaporation is very important in water resources management. There are various methods for measuring and estimating evapotranspiration (ET) that are used according to their accuracy and cost. These models include using evaporation pan and using meteorological models such as Bowen ratio and eddy correlation methods. Nowadays, modern methods such as utilizing satellite remote sensing images are developed to estimate evapotranspiration in different regions. Surface Energy Balance Algorithm for Land (SEBAL) is one of these algorithms which is highly regarded. SEBAL estimates ET as a residual in energy flux in the surface of land. This is done by calculating the difference in the soil heat flux and the sensible heat flux from the net radiation.
    Material and
    Methods
    Initially, SEBAL was extensively used for mapping evapotranspiration in lands and vegetation cover such as crop field, but it was rarely used to estimate evaporation from water bodies, especially freshwater bodies. The aim of this study was to use SEBAL algorithm to map evaporation from freshwater of dam lakes. In this regard, three Landsat Thematic Mapper images (TM) acquired in May 29th, July 9th, and August 1st, 2011 were provided from Amir Kabir (Karaj) dam and the downstream agricultural lands. The selected area is located between two provinces of Tehran and Karaj. Amir Kabir dam supplies a part of drinking and agriculture water for these two provinces. To implement SEBAL method, radiometric and geometric corrections were performed and image bands were converted to radiance and reflectance values according to their wavelengths.
    In order to prepare required parameters of SEBAL, meteorological data measured by Karaj meteorological station at the selected dates were provided. These data included elevation of meteorological station, daily solar radiation, dew point temperature, wind speed, and air temperature. Furthermore, the evaporation values recorded by Tehran Regional Water Authority located at the southwestern part of the dam using evaporation pan were used as ground truth data which measurements and were performed in related dates.
    All of the implementations of this research were accomplished using the ENVI 5.1, Excel 2007, Ref ET, and MATLAB R2012a software. The instantaneous ET at the time of satellite overpass was calculated calculate using SEBAL method and in order to calculate the daily ET, the calculation of the reference ET was necessary. To compute reference ET in this research, Ref ET software developed in Idaho University was utilized. One of the required data in the Ref ET software is hourly solar radiation. Because of the lack of hourly solar radiation data in the selected meteorological stations, angstrom method was used. Then, the ratio of instantaneous ET to reference ET was used to calculate the 24 hour ET.
    Results And Discussion
    In each stage of SEBAL method, its components, such as Normalized Difference Vegetation Index (NDVI), and Land Surface Temperature (LST) were checked to prevent the undesired errors. After performing implementations, the results showed that the absolute difference values of evaporation acquired from SEBAL method and ground truth data were 0.2, 0.2, and 0.3, in selected days, respectively, which leads to the Root Mean Square Value (RMSE) of 0.27 mm that is an acceptable value. Moreover, the total evaporation values from the entire dam surface for selected days were 8.037, 10.634, and 5.435 meters per day, respectively, which were significant values. The acquired map of evaporation from dam lake surface illustrated that the value of evaporation was increasing from coastal areas to deep regions. This was proved in the same researches. The values changed from 0.5 mm in the shoreline to 3.5 mm in deep water.
    One of the uncertainty sources of this research was the use of daily solar radiation due to the lack of meteorological data and computing hourly values by using Angstrom method. Another uncertainty source is utilizing empirical relations such as relation of estimating atmospheric transmissivity, and narrow band emissivity and broad band emissivity which is better to calibrate before use. Another shortage of SEBAL method which can lead to uncertainty is empirical process of selecting cold and hot pixels which are used to estimate air temperature and soil temperature, respectively.
    Conclusion
    Despite the mentioned shortages of SEBAL method, the results showed the applicability of SEBAL method to mapping and estimating evaporation from freshwater lakes and dam lakes as an accurate and inexpensive method. Furthermore, the evaporation from freshwater lake surface was calculated using SEBAL model which were significant values in selected days and proved the requirement for protective operations.
    Keywords: SEBAL algorithm, Evapotranspiration, Satellite images, Lake Dam, Mapping
  • Akbar Moradi *, Mohammad Reza Malek Pages 71-85
    Introduction
    The combination of spatial analysis, different methods of positioning and mobile and ubiquitous processing, positioning technology such as global positioning systems and a part of spatial analyses and GIS equipment have led to the emergence of a new trend as context-aware and mobile GIS. One of the context-aware services that has been welcomed by most people is location-based services. Location-based services provide services to users using the user’s position. Tourism is one of the areas that can be focused based on these applications. Tourists need structured information that is available to them at any moment and any place. This information helps them to justify their position to the place that may be new and unfamiliar to them. It helps them to find their desired locations and the best path which leads to that location. Context-aware systems match their behavior based on these contexts by examining the user’s current contexts.
    Materials and Methods
    To design and implement a context-aware tourism system, we initially should identify effective contexts, and specify and model the effect of each of these contexts. In this research, location context is used to provide services such as finding the right places like tourist spots, historical sites, gas stations, restaurants, hotels, hospitals, etc. which are close to user location, map graphic displaying , and to optimize the tour schedule. The user movement speed is another effective context in context-aware systems. Provision of information for users with different speeds is varied. Another effective context in providing services to tourists is the user movement direction. Direction can have different applications in providing information to tourists. For example, map details increase in the user movement direction or the map magnification changes according to the movement direction. For example, the size of the symbols of locations on the map can be changed according to the user’s direction. Time context is another important in providing information to tourists. This context may be dotted during a day or a period. One of the time application in the provision of information is the working time of different place.
    Results and Discussion
    Designing and implementation of a context-aware information system is usually complicated. It is well clear that mobility creates some challenges in these systems. Therefore, an operating system is needed to take the users and tourists’ demands into consideration in a dynamic environment. Context-aware applications aim to meet these needs and select various aspects of context such as the tourist or user’s current location, time, and other activities. In addition, increasing the amount of data makes it difficult to get access to this information through mobile equipment used by tourists. Accessing and finding the necessary information at the right time and with the right level of detail is very important for tourists.
    A questionnaire survey was designed to evaluate the system. A number of experts in tourism, municipality, and also citizens were asked to use the system for providing a comparison with non-context-aware systems. The results revealed that the proposed system was more efficient in terms of being easy to understand, having the necessary information, providing timely information for users, etc.
    Conclusion
    In this research, a context-aware system was designed and implemented to provide information to tourists in the city of Maragheh. The system provides related information to tourists based on contexts, such as location, movement speed, movement direction, the type of path and time context. The system introduced new contexts, that is, speed and direction. Some of the services in this system for tourists are creating tourism tours based on the type of attractions such as historic sites, sports sites, etc. In addition, the tourists can choose the type of path based on their preferences such as the shortest path, the most beautiful path, and the path of shopping centers. The implemented system was given to 20 users including 17 tourists, 2 municipality experts, and1 tourism expert for assessment. The results showed that an average of about 83.33% of users were satisfied with the implementation of the system and recommended it for using by other tourists.
    Keywords: Context, Context, aware System, Ubiquitous Geo, Information System (Ubi GIS), Tourism
  • Mohsen Bakhtiari *, Ali Darvishi Bolorani, Ataollah Abdollahi Kakroodi, Kazem Rangzan Pages 87-99
    Introduction
    Remote sensing has introduced new fields in monitoring and modeling environmental variables on different levels. One of the major advances of remote sensing is the use of quantitative algorithms to estimate the earth’s surface variables. Therefore, it can be regarded as a research and application framework in order to forecast and counteract devastating effects of environmental crisis. Meanwhile, capabilities of MODIS sensor in terms of its various products to estimate the environmental parameters have been explored more than any other remote sensing instruments. Optical remote sensing modeling techniques are robust and strong enough for modeling the relationship between land surface variables and the quantities measured by remote sensing data.
    Materials and Methods
    This research focuses on developing and introducing a new spectral index for modeling the Land Surface Temperature (LST) and vegetation, simultaneously. Land surface temperature is a key parameter in the balance physical processes of the Earth’s water and energy on different levels including from regional to local scales.
    On the other hand, studying the temporal and spatial variations of vegetation and temperature in different areas as an indicator showing the environmental conditions has the great importance for current and future behaviors of the surface. Therefore, combining these two parameters can lead to high synergies in the use of satellite data for studying the environmental status of the west Asia as the area is experiencing one of the most horrifying environmental degradations of the world. In order to evaluate the developed index, the spatial-temporal relationship of the Normalized Health Environmental Index (NHEI), in relation to the behavior of dust sources in the west Asia is investigated. The main steps of this study include the developing and introducing the remote sensing index that reflects the simultaneous behavior of environmental variables, trending the index based on its changes for the west Asia and finally applying that in studying dust sources of the studied region. The Normalized Health Environmental Index, (NHEI), is developed using MODIS products consisting of MYD11A2, MYD13A2 and MOD44W products. The developed index considers the spatiotemporal behavior of Land Surface Temperature (LST), and vegetation cover, simultaneously. This index is useful for monitoring the environmental health situation of lands by masking the surface water bodies. NEHI is a dimensionless parameter and the range of its values is between -1 to 1. The smaller values indicate that conditions in the region in terms of land surface temperature, vegetation, water and the environmental relevant phenomena are more critical.
    Results and Discussion
    NHEI was used to analyze the trend changes of the most important dust sources in the West Asia during last decade. Due to the high correlation between the results obtained from NHEI and the activities of the origins of dust storms, it can be adapted as a basis for modeling the behavior of these phenomena while such relationship has not been confirmed through applying the conventional indices such as NDVI. NHEI is developed and analyzed for 2002 to 2013. The trend of changes was detected by linear trending process and its relationship with dust sources has been evaluated. Since NHEI shows the changing trend of key elements of the environment, i.e. temperature, vegetation and humidity simultaneously, the results of trending reveal the general decrease of severity and extend of the index. While the distribution of dust storm hot spots in terms of the index values is showing more scattering for the whole of the west Asia. Although NHEI is not a pure physical parameter with certain and standard unit, however, because of reflecting the combined effects of NDVI and LST as well as its simplicity and strong correlation with environmental parameters, it can be used as a reliable reference index in the environment research at local and macro-scale. Then the values of NHEI within specific land covers were determined, so it has distinct values for different land covers.
    Conclusion
    This study emphasizes on NHEI capabilities in monitoring and modeling environmental variables associated with dust sources, therefore, the average of NHEI in dust sources individually and totally was significantly less and more critical than the value of NHEI in other areas of the study area. Generally, the results of this study can open a new horizon in the field of land surface variables modeling and investigation by developing new remote sensing indices especially in land degradation and dust storm investigations.
    Keywords: MODIS products, Normalized Criticality Environmental Index, Trending, Dust sources
  • Heydare Lotfi *, Hosseyn Musazadeh Pages 101-117
    Introduction
    In order to analyze the reduction of the impacts of natural hazards, particularly the earthquakes, four basic constituents such as conceptual understanding of development, vulnerability, recognition of the concept of risk, conceptual understanding of capacity building, and also, the recognition of risk management approaches are essential. Earthquakes and mass movements are a function of environmental factors, and identifying and segregation of seismic areas and hazard zonation is an important step in assessing environmental hazards. Therefore, Geographic Information Systems (GIS) and multi-criteria decision-making systems are the appropriate tools for zoning land in relation to seismic hazard. In this regard, the study of earthquakes and the areas with high seismic potential for all-round planning and management is imperative and inevitable. Therefore, the present research aims to study the vulnerable areas against natural hazards in Iran.
    Materials and Methods
    The present research is descriptive-analytical with regard to the nature of the problem and the study subject, and is a type of applied studies with an emphasis on quantitative methods. The purpose of the study is to investigate the vulnerable areas against natural hazards with an emphasis on earthquakes (Case study: Iran). In this research, the Modis Image (MOD11A1 product) of Terra satellite was used for the years 2000 to 2018. These images have a resolution of one kilometer. Therefore, each pixel of these images covers an area of about 100 hectares of land. To identify the sites with high seismic potential, criteria such as: altitude, earth temperature, the numbers of seismic events between the years of 2000 and 2018 were taken into consideration. In order to calculate the density and intensity of the earthquakes occurring, the data from the United States geological site (related to Iran) was used, and the final output was calculated by the interpolation methods of geo-statistical IDW model - a technique which predicts unknown points based on the correlation between the measured points and their spatial structure - and the arithmetic overlapping in the GIS environment. All processes and data analysis were used in the GIS environment and eventually the overlay of the final output was determined in the form of a map (vulnerability).
    Results and Discussion
    In order to measure the impact of effective factors on earthquakes, the analytical software mentioned in the research methodology section was used and also, to determine the indexes effective in determining low and high risk areas for identifying the seismicity and land evaluation for different types of activities and the amount of importance of each of these criteria relative to each other with regard to the present state and the collected information and the investigation and study of the books, previous plans and experts’ opinions have been implemented, which has ultimately entered into the GIS in the forms of information layers. In the next stage, the information layers are given weight proportional to the degree of importance and its effect on the selection of the appropriate field. In order to achieve these indices, a series of maps and databases were needed so these were prepared in the GIS environment. In this research, it is assumed that by analyzing long-term time series of satellite data, such modifications can be monitored. Therefore, in this research, the profile of temperature changes was analyzed using the MOD11A1 product of the Modis sensor during the years 2000 and 2018 in Iran. the results of the research show that the temperature variation pattern for each class is different, and in general, show the increase, stability, and then logical increment over the 18-year period, which can help researchers to identify temperature changes and consequently, to select the appropriate time period to take an image to investigate the changes in the coverage of the study area.
    Conclusion
    The study area, with regard to the mainly low topography, tectonic activity and high seismicity, diverse geological and climatic conditions, have the major natural conditions for the creation of a wide range of earthquakes, and these earthquakes bring a lot of financial losses to the region annually but unfortunately, all periodic studies have been carried out without accurate and efficient planning by the relevant authorities to date. Therefore, studying and zoning of susceptible seismic areas is necessary from an absolutely scientific view. Given the obtained finalized map and the study of temperature changes and occurring events, it can be concluded that parts of the south and southwest (Bushehr, Kermanshah, Hormozgan, Khuzestan, Ilam) are very vulnerable and exposed to severe damages. Also, the latitudes related to the central half and the southeast of the country (Kerman, Sistan and Baluchestan, southwest of southern Khorasan, east of Yazd) are exposed to moderate to high damages, and the northern part of the country (Golestan, Mazandaran, Gilan, Ardebil) are located in low damage zone because with regard to the thermal investigations within the framework of the seismic identification, they are located in the high to low thermal zones. Therefore. We find out that more than one third of Iran is faced with high, one third with moderate and one third with relatively low risk. One of the main causes of the earthquake is the high heat inside the Earth where is very hot and reaches to five to six thousand degrees Celsius. Wherever there is heat, there is movement as well, so the heat of the Earth’s center moves to the top layers and displace them.
    Keywords: Earthquake, Vulnerability, Temperature variations, Seismic events, MODIS MOD11A1 images, GIS, Iran
  • Zahra Bahari Sojahrood *, Reza Aghataher, Mohsen Jafari Pages 119-128
    Introduction
    Earth roughness represents a fluctuation of the earth’s surface, and it can be called the complexity of the earth (Wilson, 2012). Roughness calculation is of great importance and is the basis for lots of decision-making. There are various solutions for the roughness calculation.
    The first description of roughness was presented by Kupers, in which the roughness surface is assumed to be a set of points (Kupers, 1957). According to this definition, the deviation from the height criterion of the points is considered as the roughness index.
    The calculation of roughness in vast areas is possible only through satellite interpretation. The images used for this purpose should be of considerable power (Ghafouri, 1394). The main purpose of this paper is to automatically determine the parts of the area using the digital elevation model (DEM), which are desirable for the user in terms of roughness. To achieve this goal, a local decision-making support system is needed. In most of the mentioned methods, roughness is calculated as a variable in a region. But, the purpose of the paper is to calculate the roughness in different parts and to select the optimal area of the user. In previous methods, in order to achieve the goal, the roughness variable had to be calculated in each range and these ranges had to be compared one by one. This process is time-consuming and sometimes the desirable accuracy is not obtained. Therefore, there is a need for a method that reduces the time and increases the accuracy. For other purposes of this paper, we can refer to the calculation of roughness on a surface.
    In this research, a new method was developed for determining the areas with the user’s desirable quality of roughness using a DEM and based on the fractal method and spatial decision-making support system and a system with robust tools was designed and implemented for estimating the roughness and it was tested by the digital elevation model of Iran. The results indicate that this method is very accurate.
    Materials and Methods
    Ground roughness is an important variable used in the sciences of the earth and astronomy. There is no unique definition for it. It can be defined as a variable to express the variability of the Earth’s surface on a certain scale.
    In this research, to determine the favorable areas of the user in terms of roughness, a number of methods including sigma T, sigma Z, fractal geometry and a developed method of fractal geometry were used to calculate the roughness. Various spatial analyses were also used in the system. Finally, the spatial decision-making support system was developed for ranking and selecting the patches.
    Results and Discussion
    The system was implemented in the ‘Visual Studio’ environment using the ‘C #’ language and the ‘arcengine’ library. This system consists of several parts. First part, is the determination of the area whose roughness is to be determined. The second part, is the extraction of the patches of that area, the third part, which is done after the extraction of spatial complications and descriptive information of each patch, is similar to a filter which is based on roughness calculation methods. The four parts is, the ranking of these patches, and the fifth part, is their classification.
    The system is designed in such a way that the digital elevation model of any areas with any accuracy can be used. In this research, a 90 meter digital elevation model of Iran and the raster layer of its slope (produced in ArcGIS environment) were used. To display, Google maps were used.
    This method has a high precision due to its pixel-to-pixel scanning capability of the area and it seems to be more accurate than the existing ones.
    In most roughness determination methods, there is a method that calculates the roughness in the determined area. But, in this paper, using a spatial decision-making system and using the division of the region into smaller regions, the desired qualitative areas of the user are determined in terms of roughness, therefore, this method is able to decide automatically with regard to the user’s needs.
    Quality is different for various applications in terms of roughness. Sometimes high roughness and sometimes low roughness is favorable. However, other methods only calculate an amount of roughness of a region and we have to extract the values for each part of the earth and apply the analysis to it, and then compare them to determine their desirability. Several methods of calculating the roughness can also be used in the system simultaneously.
    Conclusion
    Earth roughness is a term used to describe the irregularities of an area. In most cases, determining the roughness of the earth is very complicated. There are many methods for calculating the roughness. The proposed method in this project is an innovative idea which is based on spatial analysis, spatial decision-making support system and roughness calculation methods and is calculated using the Digital Elevation Model. The results show that this method is a powerful tool for calculating roughness.
    In order to improve and continue this work, the correlation of variables is suggested in the calculation and evaluation of the obtained results. In this paper, the values are also calculated at the surface of each patch and in rows regardless of the direction. Various models can be used to consider the order of cells in each patch and compare the results.
    Keywords: Roughness, Decision support system, Ranking, Classification, Spatial analysis
  • Kamran Karimi, Gholamreza Zehtabian, Marzban Faramarzi, Hassan Khosravi * Pages 129-140
    Introduction
    Land use changes is a widespread and accelerating process, mainly driven by natural phenomena and anthropogenic activities, which in turn drive changes that would impact natural ecosystem. Because of the human population growth and its impacts, land-use patterns are changing very fast. Most of the population in Iran depends on agriculture, so the land use changes are mostly linked to agricultural developments. In recent decades, rapid land use changes have been associated with the degradation of natural resources, especially in sensitive ecosystems. On the other hand, like many other developing countries in the world, significant land-cover changes have been occurred in Iran within two last centuries. These changes were primarily due to human activities in connection with the population increase, which forced people to clear forest for cultivation and other activities. This study tries to present the effect of irrigation systems on land use changes since over three decades.
    Methodology
    Abbas plain with a surface area of 34104 ha, is located in Ilam province near the Iran’s western border. The average of annual precipitation and temperature are 207mm and 26.1o respectively. Karkheh dam, one of the largest soil dams in the world and the largest soil dam in Iran and the Middle East, located 15 km east of Abbas plain. The Karkheh Dam is designed to irrigate 320,000 hectares of downstream land including Abbas plain. The water transfer project to the Abbas plain was launched in May 2005. In the present study area, changes in land cover were evaluated in the pre and after- exploitation period of irrigation networks of Karkheh dam to the Abbas plain in Ilam province, Iran. To obtain more accurate results, Landsat sensors imagery of TM, ETM and OLI were used for the years of 1989, 2003 and 2013, as well as topographic maps, Google Earth images and area coverage. To classify the land use changes, supervised classification method with maximum likelihood algorithm was applied in the ENVI4.8 software. Images of all three periods were classified into five classes: rangelands, agricultural land, residential land, river bed and barren lands and hill moor. In order to determine more precisely changes, areas were obtained for two other periods.
    Results
    The classification accuracy results showed that the Kappa line was more than 87% for every three years and the overall accuracy obtained were 90.43%, 92.28% and 94.76% respectively for these years. The results also showed that barren lands and hill moor class has covered the largest area of this study place during the two periods (pre and after- exploitation), so that, it was 12344.1 hectares in the first period and 17370.5 hectares in the second one. In both study periods, the rangeland class has been destroyed, but in the second period 13.8% was destroyed more than the first one. Due to the exploitation of irrigation systems by farmers in the second period, more changes in land use have been converted to agricultural use, so that, 3671.8 hectares (55%) have been added to these lands during 10 years. The growth of residential areas was 0.27% of the study area after channelling, which was estimated 1.6 times higher than the first one. The area increase average in this class is 10.2 hectares per year. The most frequent conversion to farm use was barren lands and hill moor class. These lands have undergone a change by residents of the region due to their location between agricultural lands and a short distance from irrigation systems. A large number of land use changes can be prevented by defining the scope for agricultural land.
    Conclusion and
    Discussion
    In the present study area, irrigation has been in practice since over 25 years ago. Significant land-use changes have occurred in the study area in response to the Karkheh Dam from time to time affecting agricultural productivity leading to land-use changes. Unfortunately, some parts of these changes are out of schedule and unskillful and, that is significant for planners to know about these. All in all, for providing management activities and environmental programmes, accurate data on land use changes are essential. Satellite images and maximum likelihood algorithm provide the baseline data essential for proper understanding on the land-use patterns in the past and its impacts. It is also proper to understand the past land use changes ratio, and the physical and socio-economic factors behind.
    Keywords: Land use, Change detection, Kappa coefficient, Karkheh Dam, Abbas Plain
  • Amir Mahdi Emamizadeh Mahabadi *, Kamran Lari, Mojtaba Zoljoodi Pages 141-152
    Sedimentation in ports’ access channels is a major problem for the port authorities as well as the vessels navigating in these channels. This phenomenon creates dangers for the ships in this vital part of the port in addition to imposing heavy costs on the port. In this research, we evaluated and estimated the sedimentation rate and volume in Imam Khomeini port’s access channel based on field information as the research goal. In this research method, analyses on the geographic status such as bed level, analysis of wave time series and tide (as current) were carried out in the region by Mike 21 software, and appropriate modeling was presented. To investigate the rate and volume of sedimentation, the methods of hydrography, Bijker’s theory and modeling by Mike 21 were used. In the present study, hydrodynamic model of current and sediment transport will be carried out using valid engineering methods. At the same time, all information and library data and the results of existing field data are collected and analyzed, and the results obtained from different methods (Hydrography, Bijker and Mike 21) are calibrated. In line with the objectives of the study, the following cases can be summarized as:- Collecting required data and statistics such as wind, wave, current, sediment characteristics of the region or grading, and sounding data.
    - Investigating the variety of dredging methods and equipment available in the world.
    - Examining different types of discharge methods, and diverse applications of the extracted sediment.
    - Computations and modeling.
    - Summing up and conclusion and analyzing the results.
    The hydrographic boat moves on specific paths according to a predetermined schedule in order to estimate the depth or carry out the sounding. The boat is equipped with a dual or multi-frequency GPS device and a sonar device. The boat receives its horizontal position from the GPS. The sonar sends an audio wave to the bed during the movement, and gives the depth for each point by calculating the wave’s round-trip time and the sound velocity profile, and on the other hand, the GPS provides the horizontal position of that point.
    Today, various software are capable of simultaneous recording of this information, which is used in hydrographic vessel. Based on the obtained results and investigating the hydrographic maps, the actual amount of sedimentation in the channel (0/000078m^3/s/m) was obtained. Given that, the criterion hydrographic method was taken into consideration for the work and calculations in other ways, the error percentage of the results obtained from Bijker’s and modeling of Mike’s calculations were 12% and 20% respectively. Accordingly, the dimensionless coefficients of á=0.88 and =1/2 were obtained for Bijker’s theory and the results of the calculations by Mike21 respectively, which indicates good accuracy. Based on the results, the optimal method of dredging and the morphological changes of the region can be achieved based on the obtained models. Considering the sediment granularity diameter D_50=6ìm, it can be concluded that the most suitable method for dredging with regard to available facilities in the port is the use of self-propelled hopper suction dredger. However, if the dredging unit is equipped with new equipment such as bed leveler device, more optimal methods can be obtained. By this method, the total volume of sediment was 244466.280 cubic meters for an area of 57213810.4 square meters. Of course, this was the volume of solid materials, and according to the experts of the Ports Organization, this amount is 20% of the total volume of the total sediment (solids and water). It can be concluded by a simple calculation that the sedimentation rate in a one year period is about 13.7 cm per square meter per year, which shows a good approximation compared with the field measurements conducted by the Ports and Maritime Organization with a value of 13.5 cm per year. Bijker (1971) presented a method for calculating sediment transport in a combined state of wave and current. This method was expanded to calculate the sediment transport of the coastline. Bijker modified the Fryjling-Kalinske formula for the bed sedimentation along with the Einstein method to evaluate sediment transport applied in coastal environment. For this reason, the Bijker formula is very popular among the European engineers. Among the world’s leading mathematical models in analyzing the phenomena governing the sea environment, Mike21’s mathematical model is one of the most well-known ones. This advanced software has been founded, completed and developed by the Hydraulic Institute of Denmark over time and in collaboration with the Water Quality Institute of this country. This software is a comprehensive system for modeling two-dimensional free flows in which fluid flow layering cannot be ignored.
    Keywords: Sedimentation, Bijker, Mike 21, Imam Khomeini Port, Access channel, Hydrography
  • Maryam Arjmand, Alireza Rashki *, Hossein Sargazi Pages 153-168
    Introduction
    Dust cycles are an integral part of the Earth system, which emits about 2000 tons of dust every year (Shao et al., 2011) and plays an important role in the global climate changes (Park & Jong, 2008). The frequency of dust events in the arid and semi-arid regions is much higher, meanwhile, dried lakes have the largest ration in dust emission (Goudie and Middleton, 2006). Hamoun e Jazmurian is a dried lake located in an homonymous topographic-low basin in southeast Iran and a main source for high dust emissions under favorable weather conditions, but so far limited studies have been carried out in this area, especially on dust. Remote sensing provides useful information about spatiotemporal variability of dust storms over the arid environment of the world. So the present study examines the spatiotemporal variability of dust activity over the region by identifying the dust events from the satellite data.
    Materials and Methods
    In this work, spatial and temporal variability of dust aerosol were analyzed over the arid environment of Jazmurian region and surroundings located on southeast of Iran by means of monthly mean data, including Absorption Aerosol Index (AAI), values products of TOMS-Nimbus7 (N7) (1979-1984), TOMS-Earth Probe (EP)(1990-2005) and OMI (2005-2014) as well as Deep Blue AOD of MODIS-Terra (2000-2007) and MODIS-Aqua(2002-2014) and Aerosol Optical Depth (AOD555nm) of MISR (2000-2013).
    Results and Discussion
    The results indicated that several hot points of dust including Sistan/Hamoun, Rootak, a region in Pakistan near the border with Iran, Makran coast, Gwadar Bay ion the southeast corner of Iran and the Jazmurian region. Overall, the annual trend of both AAI and AOD values obtained from all sensors, are increasing during the periods expect MODIS retrievals which has negative partial amounts, the time periods of 2002-2004, 2008-2009 and 2011-2012 are the peak of dust storms over the Jazmurian region because of human activities and severe droughts. Seasonal variations of AAI and AOD values showed the major dust activities occur during spring and summer and it is minimum in autumn over Jazmurian region. high activity of dust storms are in four months of May, June, July and August and low in the four months of November, December, January and February
    Conclusion
    Hamoun e Jazmourian is one of the active dust emission regions in south east of Iran. The amount of dust and affected areas have increased in recent years. Severe droughts in recent years and numerous dam construction are one of the main factors of dust emission increase in this region.
    Keywords: Dust_AAI_AOD_Hamoun e Jazmurian_Satellite data
  • Ali Akbar Rasuli, Ali Mohammad Khorshiddoust, Mojtaba Fakhari Vahed * Pages 169-178
    Introduction
    Lightning is one of the most fascinating climatic phenomena, which has not yet been fully understood. This phenomenon usually occurs during thunderstorms and at the times of electrical field failure in a variety of cloud-to-ground, cloud-to-cloud, and in-cloud or intra-cloud. The cloud-to-ground lightning which strikes the ground is one of the most important causes of mortality due to weather conditions. Lightning can also cause many financial losses such as damaging power lines and causing fire. Therefore, spatial distribution of lightning is essential in terms of energy and safety management. Furthermore, our community, which increasingly relies on information networks, helps to identify the areas prone to lightning in order to protect the information systems. Lightning activities vary widely on the spatial and temporal scales, and depend on local convectional activities to some extent. The knowledge of lightening activities was usually based on surface measurements over time, prior to the arrival of the satellites. But, the activity of these storms is not measured in places where there are no synoptic stations. Therefore, it is necessary to predict the exact location and the severity of convective storms based on the development and monitoring of the route for timely notification. This is because all measurements related to thunderstorms in Iran are recorded with a three hour interval in various codes and only at synoptic stations.
    Materials And Methods
    This study was carried out using lightning data recorded in space by LIS sensor in a period from January 1998 to December 2013 (16 years). Lightning imaging sensor (LIS) is installed on the TRMM satellite. The LIS sensor is an optical detector that measures light-induced and light-intensity variations in clouds in the range of 777 nm/s and is capable of observing thunderstorms with a scale of 3 to 6 km on a 600x600-km while the effective LIS efficiency is 90% at night and 70% at local noon time.
    At the first stage of data analysis, it should be determined that the data are randomly distributed or have a certain spatial trend. Some of geographic processing functions were applied to data in the GIS software to compute the statistical values and to determine the locations having significant lightning levels. These calculations are done based on the Euclidean distance between the points (thunder and lightning) and the spatial concept of that weighting method based on the inverse distance. Other indices also compute the spatial distribution of the data. The nearest neighbor index (NNI) and the Kernel density function are among these indices. The NNI is expressed as a proportion of the observed distance to the expected distance, assuming the random distribution of the images. To generalize the geographic location of a phenomenon (lightning occurrence) to the whole area, the Kernel density interpolation estimator has been used throughout the region. In fact, the Kernel density function in the GIS software calculates the density of the features in their neighborhood and can be used for linear and point features (lightning).
    Results And Discussion
    The results of this research showed that the maximum frequency of lightning occurs in the southeast of Iran in the months of March to August (warm period of the year). Its highest frequency is in August and its lowest frequency is in December. In the study of daily changes it was also found that from the early afternoon until late afternoon (from 1300 to 1600 hours local time), the lightning activities significantly increase, which seems to be related to local convectional activities which are along with the surface heat created by daily radiation of the sun. The nearest neighbor index results showed that the data distribution follows the cluster pattern. In other words, some regions have more favorable conditions for lightning. The results of the Kernel density index indicated that these areas are in the southern slopes of the region and its maximum is located before the main peak. The maximum frequency of lightning lies between 26° and 27° N, and is on the same orbital direction. Given the maximum lightning occurrence time which is during the warm period of the year, it seems that the southern currents created by the monsoons of the Southeast Asia along with local topography, is the exacerbating factor for the lightning activities in the southeast of Iran, and in particular, the region with a maximum lightning activities.
    Conclusion
    The use of satellite data to illustrate the distribution of some climatic phenomena can be very useful, since the frequency of some phenomena (especially lightning) is not recorded on ground stations. On the other hand, the distribution and density of ground stations are not appropriate, because the density of synoptic stations is particularly in low mountainous regions and the shape of the land in these areas is complex, and the distribution of thunderstorms is affected by this form of land. As it was observed in the results, one of the most important factors of the frequency distribution of lightning is the roughness, and these results indicate that remote sensing technology can be used to calculate the distribution of the phenomena of interest with high precision.
    Keywords: Lightning, LIS, Kernel Density Functions, Southeast of Iran
  • Mahdieh Soltani Gerdfaramarzy *, Gholamali Mozafari, Shahab Shafie Pages 179-199
    Introduction
    Droughts are one of the most common climatic changes that occur in many arid and semi-arid regions of the world with high intensities every few years. In many years, the occurrence of droughts is also unknown for a while, therefore, the identification of drought itself, is considered as a valuable finding for managing the water resources in areas such as Iran, most of which are formed by arid and semi-arid regions. Precipitation is the most important determinant variable in drought conditions among climatic variables. Rainfall is the most important variable whose variations are directly reflected in soil moisture and surface runoff, variations in underground water reservoirs and others. The purpose of this research is to investigate the best method of drought interpolation in the Yazd-Ardakan plain, to identify areas at risk of this phenomenon and to identify its spatial distribution, and also to investigate the relationship between drought and the salinity of groundwater and the spatial distribution of saline water in the Great Plain of Yazd – Ardakan.
    Materials and Methods
    In this research, regarding the lack of long-term statistical period of some stations and considering the distribution of stations in this basin, the annual precipitation data of meteorological stations of Yazd - Ardakan plain during 2 long term period of 7 meteorological stations (1346-1391), and short term precipitation and salinity period of 41 meteorological stations and 47 underground water wells (1375 to 1391) have been used all together. The standardized drought index for the determining drought condition and descriptive statistics methods in SPSS software has been used to describe the state of groundwater salinity using Excel software. The Pearson, Man-Kendhal, and Spearman correlation analyses were also used to determine the relationship between drought and the state of salinity of groundwater. Finally, the Geographic Information System (GIS) was also used to map the zoning of groundwater salinity.
    Results and Discussion
    The results of the assessment showed that in the correlation analysis with all 3 Pearson, Man-Kendhal, and Spearman statistics, a negative trend along with inverse correlation is observed between the precipitation (SPI) and salinity based on the Z grade,, in none of which the significant level is observed. The existence of a strong correlation between these two parameters with a one year delay was among the other results of this research. Using GS and GIS, the best variogram model was selected and the maps of drought, groundwater salinity and salinity variations were also drawn. Generally, in most stations with negative precipitation trend, a positive trend of underground water salinity is observed, and groundwater quality has also changed more strongly in areas with more drought outbreak and its salinity has also increased.
    Conclusion
    The occurrence of droughts, on the one hand, increasing water demand in the area, on the other hand, exacerbate the shortage and need for water. Therefore, the monitoring of future droughts and wet years should be considered very important in terms of management strategies of the region. Passing such crises require the efficient management of water resources under present conditions, especially during drought periods. Usually, during such a period, the region’s water shortage, are provided from the groundwater resources and through increasing the water extraction from wells, to meet basic needs such as drinking. Therefore, in such cases, the quality issue of the extracted water from these wells becomes more important. The available statistics show that the water quality in the Yazd-Ardakan plain (electrical conductivity) is a function of annual precipitation (as the most important feature of droughts in the region), and with the annual precipitation increasing and decreasing, the groundwater quality also undergoes changes. In general, the results of the analysis of the studied parameters indicated that the climate of Yazd-Ardakan plain was associated with a rainfall reduction trend, which is one of the important factors of drought, so that, its consequences have also affected the level and quality of water resources. It has been observed in this research, that droughts have had a considerable effect on the salinity of groundwater in most of the areas. Therefore, it is generally stated that the groundwater quality has changed more strongly in areas with more drought outbreaks and its salinity has increased.
    Keywords: Drought, Subterranean Waters, Salinity, Geostatistical, Geographic Information Systems (GIS), Yazd, Ardakan Plain
  • Mohsen Pour Khosravani *, S. Elham Mousavi Pages 201-212
    Introduction
    Natural conditions and physical limitations determine the suitability of an area for the development of the city. Therefore, ignoring the effects of these factors and conditions such as the position of the floodplain, steep, existence of bedrock ... on the development can cause serious and complex problems (sarvar, et al., 2014, 96). Urban development is the harmonious and balanced expansion of the surface assigned to the residential buildings in a city, with the surfaces required by other applications at a standard level (ghrekhloo et al, 2011). In many sources, the physical expansion of cities is defined as a dynamic and continuous process in which the physical limits of the city and its physical spaces increase in vertical and horizontal directions in terms of quantity and quality (Pour Ahmad et al, 2014). High population growth and migration caused unplanned constructions and unrestrained expansion of cities and has created a lot of changes in their spatial constructions. The lack of knowledge and awareness of these limitations and the lack of preserving their limits led to the development of the city towards these obstacles and ultimately, urban areas will face serious problems. Therefore, the balanced development of cities requires planning principles. Accordingly, this research tries to determine the optimal areas for the physical development of the Dalaky and Vahdatiyeh towns, while considering the variables affecting the location of these two towns with the help of the Geographic information system (GIS) and mathematical methods of MCDM.
    Research
    Methodology
    The research method in this study is descriptive-analytical, based on practical type. In this research, the required information was collected using field and library methods and then, the subject under study was investigated using Excel, AutoCad, ARC GiS and GOOGLE Earth software and SAW, Dematel and AHP methods in two stages. At the first stage, geomorphological maps were prepared as the base maps using 1: 100000 geological and 1: 50000 topographic maps -K753 series, pages 6148 IV and 6248 I, digital elevation model (DEM) and satellite imagery. Then, at the second stage, the AHP method was used to weight the sub-criteria and the SAW, DEMATEL and AHP methods were used to weight the main criteria of the research and ultimately the final map was prepared. In general, AHP helps decision-makers to choose the best option by comparing criteria and sub criteria. In this way, decision-makers compare criteria and sub-criteria in pairs, and there is no need to consider all criteria at one stage.
    Results And Discussion
    The variables and indices in this study are 5 criteria: slope, mother materials, geoform, land surfaces and climatic elements; and 6 sub-criteria: distance from human elements, distance from runoff, distance from the tectonic structure, temperature, precipitation, wind speed; and 10 indices: distance to urban settlements, distance from the road, distance from groves, distance from agricultural lands, distance from the alluvial fans, distance from the river, distance to Galli, distance from alluvial terraces and distance to reverse and strike-slip faults. After evaluating these indices, AHP, Dematel and SAW techniques were used to analyze them.
    Conclusion
    Urban physical development is one of the main issues of urban growth, and if the physical development is not a desirable location in cities, there will be many negative impacts both from natural and human aspects on the cities. Unauthorized growth of urban areas and the development of these areas in the natural environment regardless of natural hazards, recognizing regional geomorphic conditions, environmental hazards, and urban planning are necessary to determine the safe and sustainable environment for the expansion of cities. In this research, the geomorphological and environmental hazards in the study area have been investigated using the Saw, Dematel and AHP models; the opportunities and constraints have been expanded in different directions of the Dalaki and Vahdatiyeh cities, and finally the best direction for the expansion of these cities in the future was determined.
    Although both the DEMATEL and AHP model compare each parameter to other parameters, but, because the AHP model compares the weight of the classes of each criterion based on the preference of one class to all classes of that criterion, it provides better results. The results show that the SAW method also suggests some results by direct determination of the weights. Therefore, with regard to the contradiction of the final results of parameter weighting, the weights have been integrated in this research using the average rating method. Accordingly, the mother material parameter with an average rating of 1.33 is the most preferred parameter, and the slope and land surface parameters with an average rating of 3.67, have the least preference in weighting factors. According to these surveys, the lands of the south-east, north, north-east and the eastern slopes are the most suitable directions for the physical development of two towns of Dalaki and Vahdatyeh.
    Keywords: Geomorphology, Physical development, Environmental hazards, MCDM, Dalaki– Vahdatiyeh
  • Alireza Soleimani, Ahmad Aftab *, Ali Majnoony Tootakhaneh Pages 213-227
    Introduction
    Many of the problems that occur in the national security area should be sought at the border. Because undoubtedly, there is no element more important than the element of security and providing peace and calm in the society, for the progress, development and unilateral evolution, as well as the flourishing of talents, and social development. Creativity and valuable activity are not possible without security. The negative effects of border areas’ insecurity in the villages are more than cities. Because, rural areas are more vulnerable due to the developmental gap between villages and cities. Due to the vulnerability of the border villages, it is necessary to ensure the security of the villages through passive defense measures.
    West Azerbaijan Province with 980 km of common land border with Iraq, Turkey and the Republic of Azerbaijan and possessing ethnic cultural diversities has not been an exception to this rule. The conditions of the eight years of the imposed war, the crises of the neighboring countries of Iraq, Azerbaijan and ethnic conflicts in Turkey have caused insecurity in the geographical boundaries of the West Azerbaijani province. In this regard, the present research investigates the spatial structure and assessment of the vulnerability of rural settlements in the border regions of Iran and Turkey with an emphasis on passive defense approach.
    Materials and Methods
    The study area includes parts of West Azerbaijan province which is bordered by Turkey and includes the cities of Maku, Chaldoran, Khoy, Salmas and Urmia, and 1259 villages with a population of 568843. The main method of this research is descriptive-analytical. In order to carry out the spatial analysis of the rural settlements in the border regions of Iran and Turkey with regard to the passive defense approach, the eight major criteria (water resources, natural hazards, landforms, security considerations, climate, demographic considerations, access to facilities, land quality) were selected with 17 sub-criteria based on internal and external sources investigation. Then, using the network analysis process, the amount of importance coefficients of the criteria have been determined. In the next stage, the information layers were produced by the GIS in proportion to the indicators, and were integrated with regard to the capabilities of the GIS, and the extent of the vulnerability of settlements was extracted through the overlapping of the information layers.
    Results and Discussion
    Based on the results, security considerations with a score of 0.349 have the highest effect and significance. Meanwhile, the index of the distance from the border has the highest role with the rate of 0.1021. Demographic considerations with a score of 0.232, and environmental hazards with a score of 0.150 stand next with respect to the importance. In the cluster of demographic considerations, population density with a score of 0.0231, and in the cluster of environmental hazards, the distance from the flood-prone areas with a score of 0.0078 have had the highest effect. Among the main criteria examined, the quality of land and water resources are the least important with the importance rate of 0.019 and 0.026, respectively. Based on the results obtained, 17.9% of the study area was found to be a highly vulnerable zone. 123 villages with 8.3% of the population of the study area are located in this zone. The zone with the high vulnerability covers 17.5% of the area. 243 villages with 18% of the population are located in this zone.
    Conclusion
    The overall results of this research showed that by adopting a passive defense approach, the natural and human threats of border rural areas could be reduced. In this regard, in this research, in order to analyze the spatial structure of rural settlements in the border regions of Iran and Turkey with a passive defense approach, eight major criteria were identified.
    Security considerations with a score of 0.349 have the highest significance and impact on analyzing the rural settlements of the border areas of Iran and Turkey in terms of passive defense. Meanwhile, the index of the distance from the border with the rate of 0.1021 has the highest role with respect to the passive defense approach. In the next stage, demographic considerations with a score of 0.232 and environmental hazards with a score of 0.150 stand in terms of importance. Given these findings, the following solutions are proposed:• Identifying and eliminating the damages caused by the proximity of villages to the border point and the observation of the transboundary threats.
    • Creating job diversification among the border villages to reduce rural dependency on land.
    • Promoting the role and functions of border cities, including mid-range cities, in comprehensive rural development.
    • Encouraging people to stay in villages through investing in rural infrastructure.
    • Enhancement of the presence of military and law enforcement forces at the border level.
    Keywords: Spatial analysis, Rural settlements, Passive defense, Security, Border areas of Iran, Turkey
  • Alireaza Darbane Astaneh, Sajad Ferdowsi *, Hamid Reza Shahmohammadi Pages 229-239
    Introduction
    Marine tourism is one of the most attractive and most popular tourist branches that has flourished much in recent decades and has attracted a significant part of tourism economy. In the meantime, despite having extensive coastal borders in the north and south, Iran has not yet been able to provide tourists with desirable services in relation to marine tourism. The constructing of marine tourism sites in coastal areas is one of the measures that can be taken in this regard. In order to locate such sites, it is needed to take the following criteria into consideration: distance from the sea, view of the sea, exposing to the sun, land use, distance from natural hazards such as faults, floods, erosion, distance from the residential areas, distance from the rivers and lakes, distance from road networks, distance from protected areas and percentage of slope. In this regard, the present paper aims to determine the most appropriate places for the construction of marine tourism sites in the city of Tonekabon, considering the importance of quantitative and qualitative identification and assessment of the characteristics of the areas. It is hoped that managers and planners can provide the ground for developing marine tourism on the southern margin of the Caspian Sea in accordance with the available capacities, by assessing and analyzing this process in the coastal areas of this Sea. The present research seeks to answer the following question: Where are the most suitable places to build a marine tourism site in the city of Tonekabon?
    Materials and Methods
    The present research with descriptive-analytical method aims to identify the most desirable locations for the construction of marine tourism sites. The required information was collected by a library method. In order to weight the criteria under study, the opinions of 32 experts were surveyed and the AHP method was used. After determining the weight of each criterion, the information layers of each of the criteria were prepared in the GIS environment and finally, with overlaying of the information layers, the most suitable locations for the marine tourism sites were introduced.
    Results and Discussion
    According to the experts, the criteria of exposing to the sun, slope percentage, sea view, land use, severity of erosion in the area, and the criteria of distance from the sea, distance from the road networks, distance from the faults, distance from the protected areas, distance from the rivers, distance from the residential areas and distance from the areas subject to flood, were scored based on the distance (Table-1). Then, the information layers were created based on each of the criteria in the GIS environment and rated according to the weight of each criterion. Accordingly, four areas in the city of Tonekabon have been identified as more desirable compared to other points in order to locate the marine tourism sites.
    Conclusion
    The correct location of the various land uses by using tools, techniques, and scientific models and in accordance with the principles and rules of planning can be efficient in solving land use problems. Therefore, proper planning for the creation of marine tourism sites in the proposed places, in order of priority, will provide sustainable tourism development and mutually the economic development of the region. Accordingly, based on the analyses and the results of the research, the following suggestions are presented for the construction of a marine tourism site in general:- Accurate and complete identification of facilities and services available in neighboring settlements with the proposed location.
    - A detailed study of the proposed location for the construction of a marine tourism site
    - Investigation and feasibility of the deployment of activities related to the marine tourism in the proposed location.
    - Studying and identifying the facilities needed by tourists visiting the sea within the desired range.
    - Advertising and introducing the capabilities of marine tourism at national and regional levels.
    - Encouraging investors and local people to invest in the construction of tourism sites.
    - Allocating sufficient funds and credits to build the primary infrastructure.
    - Strengthening and improving roads and communication paths to the proposed location
    - Familiarizing people and authorities with the benefits of marine tourism and trying to attract their participation
    - Improving and enhancing the safety and security conditions within areas of interest.
    Keywords: Marine Tourism, Location, Caspian Sea, GIS, AHP