فهرست مطالب

فصلنامه پژوهش های جغرافیای طبیعی
پیاپی 104 (تابستان 1397)

  • تاریخ انتشار: 1397/04/06
  • تعداد عناوین: 12
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  • نسرین عبدالخانیان، هیوا علمیزاده ، علی دادالهی سهراب، احمد سواری، محمد فیاض محمدی صفحات 207-219
    رودخانه‏ها تحت تاثیر پدیده فرسایش و رسوب‏گذاری دست‏خوش تغییرات گوناگونی می‏شوند؛ از آن جمله می‏توان اشاره کرد به: تغییر راستا؛ جابه‏جایی‏های عرضی و طولی؛ تغییر تراز بستر؛ تغییر دانه‏بندی؛ و دگرگونی ویژگی‏های هندسی مسیر. هدف از این مطالعه تعیین محدوده فرسایش و رسوب‏گذاری در ارتباط با سرعت جریان و پخش آلودگی در ساحل اروندرود با استفاده از مدل کوهیرنس و GIS است. در این تحقیق از مدل سه‏بعدی و هیدرودینامیکی کوهیرنس برای شبیه‏سازی سرعت جریان استفاده شده است که معادله پیوستگی، معادلات ناویراستوکس در سه بعد، و معادله‏های انتقال شوری و دما به روش جداسازی حل می‏شوند. شرایط مرزی اعمال‏شده شامل تغییرات دما، شوری، و دبی برای مرز باز رودخانه و تغییرات دما و شوری و اعمال مولفه‏های جزرومدی M2، S2، O1، و K1 برای مرز باز دریا در مدل به‏کار گرفته می‏شود. با توجه به مقاطع عرضی و خروجی سرعت جریان از مدل کوهیرنس، پهنه تحت پوشش بیشترین آلودگی منطبق با سرعت جریان آب کمتر و رسوب‏گذاری بیشتر است. همچنین، در مقطع دهانه رودخانه میانگین سرعت در وسط رودخانه بیشتر و در دو طرف ساحل رودخانه کمتر است؛ در نتیجه، در دو ساحل ایران و عراق رسوب‏گذاری بیشتر و فرسایش کمتری انجام گرفته است.
    کلیدواژگان: اروندرود، رسوب‏گذاری، کوهیرنس، مدل‏سازی، GIS
  • محمد شریفی پیچون صفحات 221-239
    کرایوپدیمنت و کرایوپلانیشن دو لندفرم مرتبط با قلمروهای مورفوژنتیک جنب‏یخچالی‏اند که تحت تاثیر فرایندهای یخبندان و ذوب یخ به‏وجود می‏آیند. در این پژوهش به نحوه شکل‏گیری و توسعه این عوارض در حوضه آبریز تنگ‏چنار (جنوب شهر مهریز) در ایران مرکزی پرداخته‏ شده است. کرایوپلانیشن‏ها به شکل تراس‏های پلکانی بر روی برخی دامنه‏های منطقه مورد‏ مطالعه با عرض 5 تا 100 متر و در ارتفاع بالای 2000 متر با شیب کمتر از 5 درجه قابل مشاهده‏اند. کرایوپدیمنت، از نظر مورفولوژی، نوعی پدیمنت اما با ژنتیک متفاوت و غیر جریانی است که بر اثر تخریب فیزیکی سنگ‏های دانه‏ای، گرانیت، و کنگلومرای حاشیه دره و توسعه جانبی دره ایجاد شده است. نتایج نشان می‏دهد که عوامل فرسایشی جنب‏یخچالی مانند تخریب سنگ‏ها به شکل فیزیکی و انتقال آن‏ها به شکل خزش یخی، پف‏کردگی سطح زمین بر اثر یخ، حرکات توده‏ای قشر سطحی ذوب‏شده، فرسایش ریلی، ایجاد و توسعه آبراهه‏های کوچک ناشی از ذوب یخ، و در نهایت فراسایی دامنه‏ها در به‏‏وجودآوردن این عارضه‏ها نقش داشته‏اند. بر مبنای نقشه هم‏دمای گذشته، این لندفرم‏ها در دوره پلیستوسن تحت قلمرو جنب‏یخچالی ایجاد شده‏اند و بر اساس نقشه هم‏دمای حداقل دوره سرد سال در حال حاضر این عارضه‏ها هنوز در حال توسعه‏اند.
    کلیدواژگان: جنب‏ یخچالی، ژلی‏فلوکسیون، فراسایی دامنه، کرایوپدیمنت، کرایوپلانیشن
  • مهتاب علیمرادی، محمدرضا اختصاصی ، مهدی تازه، حاجی کریمی صفحات 241-253
    ویژگی‏های زمین‏شناسی تاثیر بسیار زیادی در ویژگی‏های فیزیکی حوضه و شبکه آبراهه‏ها دارد. هدف از این پژوهش تعیین بعد فراکتال شبکه هیدروگرافی و بررسی ارتباط بعد فراکتال با الگوهای ژئومورفولوژی سازندهای زمین‏شناسی و میزان حساسیت آن‏ها در حوضه‏های مورد مطالعه است. پس از محاسبه بعد فراکتال و تعیین میزان حساسیت هر سازند، ارتباط بعد فراکتال با سازندها در حوضه ‏های مختلف بررسی شد. نتایج نشان داد بین عدد فراکتال و حساسیت سازندهای حوضه‏ها، که بیانگر میزان فرسایش و ناهمواری در حوضه است، ارتباط معناداری در سطح 5درصد و افزایشی وجود دارد؛ به‏نحوی‏که با افزایش حساسیت سنگ‏شناسی و، به‏تبع آن، تراکم زهکشی، عدد فراکتال افزایش می‏یابد. بیشترین مقدار بعد فراکتال در حوضه‏ های مطالعاتی مربوط به سازند کواترنری ریزدانه معادل 65/1 و کمترین مقدار عددی بعد فراکتال مربوط به سازند سروک معادل 06/1 است. همچنین، در سازندهایی با حساسیت بیشتر نسبت به سازند‏های مقاوم تغییرات بیشتری در تراکم شبکه هیدروگرافی رخ‏ داده است؛ درنتیجه، تغییر بعد فراکتال آن‏ها نیز بیشتر مشاهده می‏شود.
    کلیدواژگان: ایلام، بعد فراکتال، سازندهای زمین‏شناسی، شبکه هیدروگرافی
  • محمدرضا محبوب فر، محمدحسین رامشت ، حجت الله یزدان پناه، مهری اذانی صفحات 255-270
    وارونگی هوا پدیده اقلیمی است که سبب افزایش تراکم آلایندگی در شهرهای پرجمعیت و صنعتی می‏شود؛ به‏طوری‏که عبور از آستانه کیفیت هوا مشکلات عدیده‏ای برای شهروندان به دنبال دارد. توجه مدیران برای مقابله با این مشکل بیشتر معطوف به عوامل آلاینده چون ترافیک است. اما باید دید اگر این پدیده در فصول مختلف وجود دارد و عوامل آلاینده نیز تغییر چندانی در طول سال ندارد، چه عاملی سبب عبور مقدار شاخص کیفیت هوا از آستانه می‏شود و اگر استمرار اینورژن موجب چنین وضعیتی است، می‏توان راهکارهای اقلیمی برای کاهش استمرار این وضعیت پیشنهاد کرد. این پژوهش کاربردی با روش تحلیل فضایی مولفه‏های اقلیمی (فشار و دما) و آلاینده‏های هوا (O3, PM, Co, SO2, NO2) و با بهره‏گیری از روش همبستگی و تکنیک کریجینگ و با استفاده از تحلیلگر Surfer انجام گرفته است. نتایج حاصل از این پژوهش نشان داد که:* در حاکمیت اینورژن از طریق هسته‏های سلولی فشار و دما امکان تحریک سلول‏ها برای ایجاد آشفتگی وجود دارد.
    * در ماه آبان و آذر با کنترل ترافیک و در دی‏ماه با کنترل آلوده‏کننده‏های صنعتی می‏توان از عبور شاخص کیفیت از حد مجاز جلوگیری کرد.
    کلیدواژگان: آستانه، اصفهان، اینورژن، شاخص کیفیت هوا (AQI)
  • ابوالقاسم گورابی ، وحید محمدنژاد صفحات 271-291
    در این پژوهش به بررسی شواهد و آثار زمین‏ساخت فعال در اطراف کویر طبس پرداخته شده است. برای تحلیل‏های کمی لندفرم‏ها از تصاویر سنتینل و نقشه‏های زمین‏شناسی استفاده شده است. ژئومورفومتری رقومی شامل اندازه‏گیری میزان جابه‏جایی و بالاآمدگی رسوبات و کانال‏ها، تحلیل نیمرخ‏های عرضی و طولی چشم‏اندازها، و ارتباط آن‏ها با داده‏های لرزه‏ای اساس کار بوده است. نتایج پژوهش نشان‏دهنده فعالیت‏های شدید تکتونیکی طی کواترنری تا زمان حاضر در منطقه است. مقایسه الگوی تغییرشکل لندفرم‏های کواترنری پهنه پژوهش از قبیل مخروط‏افکنه‏ها، مسیل‏ها و زهکش‏ها، پرتگاه‏های گسلی، و چین‏ه ای فعال با شکل نیمرخ عمقی کانون‏های زمین‏لرزه‏ها بیانگر وجود سیستم گسلی معکوس مدفون در حد فاصل کوهستان شتری- پلایای طبس در منطقه هستند. فعالیت این سیستم‏ گسلی فعال، علاوه‏بر جابه‏جایی مسیل‏ها، چین‏خوردگی رسوبات کواترنر، رشد چین‏ها، ایجاد پرتگاه‏ها، تقطیع مخروط‏افکنه‏ها، و پیدایش دره‏های بسیار عمیق کانیونی، موجب مهاجرت تحمیلی مخروط‏افکنه‏ها از جبهه کوهستان به طرف پلایای طبس (از قدیم به جدید) شده است. تداوم چنین تغییرشکل‏هایی به میزان بالا را می توان عامل اصلی تشکیل حوزه تنشی و توسعه و گسترش شکستگی‏ها و در نتیجه علت اصلی ایجاد زمین‏لرزه‏هایی با بزرگای بالا دانست که احتمال وقوع آن‏ها در آینده دور از انتظار نیست.
    کلیدواژگان: ایران مرکزی، تکتونیک فعال، طبس، کواترنری، گسل
  • حسام احمدی بیرگانی صفحات 293-305
    روش منشایابی یا انگشت‏نگاری رسوب با استفاده از حل معادلات تابع هدف یا مدل ترکیبی، برخلاف مدل‏های رایج فرسایش و رسوب در دنیا، نتایج قابل قبول‏تری با عدم‏قطعیت پایین‏تری از میزان تولید رسوب ارائه می‏دهد. الحاقیات و پیوست‏های موجود به این تابع ضرایب تصحیحی هستند که شامل ضریب تصحیح ماده آلی، اندازه ذرات، و وزن تشخیصی ردیاب‏اند و از این ضرایب، بدون هیچ‏گونه توجیه و ضرورتی، در بیشتر پژوهش‏ها استفاده می‏شود. در تحقیق پیش ‏رو اهمیت وجودی این ضرایب تصحیح در خصوص منشایابی تپه‏های ماسه‏ای غرب دریاچه ارومیه در واحدهای ژئومورفولوژی/ سنگ‏شناسی بررسی شده است. نتایج این تحقیق نشان داد سهم منابع رسوب قبل از اعمال ضرایب تصحیح، پهنه هموار ماسه‏ای (Qmf) به میزان 76/47درصد و مخروط‏افکنه‏ها و پادگانه‏های آبرفتی (Qt) به میزان 24/52درصد است؛ درصورتی‏که بعد از اعمال ضرایب تصحیح مناطق منشا به مخروطه‏افکنه سنگریزه‏ای کوهرفتی (Qf) به میزان 50/67درصد و شیل نازک لایه همراه آهک دولومیتی ضخیم (Klshi) به میزان 50/32درصد تغییر یافته است. لذا، اگر از ضرایب تصحیح موجود در تابع هدف به‏درستی و با دلیل علمی استفاده نشود، نه‏تنها ممکن است سهم منابع احتمالی تولیدکننده رسوب بیشتر یا کمتر برآورد شود، بلکه منابع تولید رسوب تغییر ‏یابد و با منابع دیگر جای گزین شود.
    کلیدواژگان: تپه‏ های ماسه‏ ای، دریاچه ارومیه، ضرایب تصحیح، منشایابی رسوب
  • لیلا گلی مختاری ، فرشته بیرامعلی صفحات 307-322
    در دهه‏های اخیر، علاقه‏مندی به رخدادهای زمینی در کشورها گسترش یافته و این امر به توسعه سه مفهوم در جهان علم منجر شده است: مفاهیم ژئودایورسیتی؛ ژئوتوریسم؛ حفاظت. ژئودایورسیتی مقایسه تنوع پدیده‏های زمین‏شناسی، هیدرولوژی، ژئومورفولوژی و خاک‏شناسی، توزیع و فراوانی این پدیده‏ها، و ارتباط آن‏ها با یکدیگر در چشم‏انداز است. اشتهارد، به عنوان یک منطقه نیمه‏کویری در جنوب استان البرز، از ظرفیت بالقوه قابل ملاحظه‏ای در زمینه تنوع زمینی برخوردار است. در این پژوهش، نخست، برحسب ویژگی‏های مختلف ژئومورفولوژی، سه واحد انتخاب و مرزبندی شد. بر اساس مشاهدات میدانی، محاسبات کمی و کیفی پدیده‏ها، و تهیه و تحلیل نقشه‏های مورد نیاز مطالعاتی انجام گرفت. بر اساس مطالعات، واحد G1 دارای بیشترین تعداد عناصر غیرزنده، G2 دارای بیشترین تنوع فرم‏شناسی، و G3 دارای بیشترین ارزش ژئودایورسیتی در منطقه است. با توجه به اینکه حفاظت در منطقه مورد مطالعه در ارتباط با پدیده‏های مورد بررسی انجام نگرفته و بخشی از این منابع زمینی در حال تخریب است، به‏نظر می‏رسد توجه به ارزش‏های مربوط به تنوع زمینی در این منطقه گامی در جهت جلب توجهات بیشتر در زمینه حفاظت از منطقه باشد.
    کلیدواژگان: اشتهارد، حفاظت، ژئوتوریسم، ژئودایورسیتی، لندفرم
  • آرش زندکریمی، داود مختاری صفحات 323-338
    برآورد دقیق خصوصیات کمی و کیفی پدیده‏های طبیعی مستلزم صرف زمان و هزینه زیاد ‏است. در این راستا، درون‏یابی روشی کارآمد شناخته‏شده است که، با ارائه و تعمیم مقادیر نقطه‏ای به سطح، صرفه‏جویی در وقت و هزینه را فراهم کرده است. الگوریتم‏های مختلف درون‏یابی مدل‏سازی مقادیر را مقدور می‏سازد که گام مهمی در مدیریت منابع محسوب می‏شود. با توجه به اینکه صحت داده‏های ورودی در تحلیل‏ها و تصمیم‏گیری‏ها از اهمیت خاصی برخوردار است، در تحقیق حاضر به ارزیابی دقت حاصله استفاده از 10 الگوریتم مختلف درون‏یابی در تخمین مقادیر بارش پرداخته شده است. در این تحقیق از Cross - Validation به منظور مقایسه الگوریتم‏های مختلف استفاده شده است. همچنین، مدل‏ها با استفاده از ریشه متوسط مربع خطا (RMSE) ، میانگین خطای مطلق (MAE) ، معیار اریب خطا (MBE) ، و ضریب تبیین (R2) مقایسه آماری شده‏اند. نتایج به‏دست‏آمده از ارزیابی دقت نشان می‏دهد که روش Ordinary Kriging با مدل تابع Circular با 0. 05- MBE=، 53. 37MAE=، 77. 31RMSE=، و 0. 70 R2 = نسبت به سایر مدل‏ها از اعتبار بیشتری برخوردار است و مناسب‏‏ترین روش درون‏یابی پراکنش مقادیر بارش در استان کردستان ‏است. با توجه به ماهیت مقایسه ای این تحقیق، نتایج آن برای شناسایی روش‏های بهینه درون‏یابی پراکنش بارش در مناطق کوهستانی از اهمیت بسیاری زیادی برخوردار ‏است.
    کلیدواژگان: ارزیابی دقت، استان کردستان، تخمین مقادیر بارش، درون‏یابی
  • مریم رحمتی، مجتبی یمانی ، راضیه لک، سیاوش شایان، منوچهر فرج زاده صفحات 339-352
    پهنه مورد مطالعه در این پژوهش بخش ایرانی قاعده دلتای اروندرود واقع در شمال‏غربی خلیج فارس به طول تقریبیKm 23 است. هدف از این مطالعه بررسی عوامل موثر بر هیدرودینامیک ساحلی طی شصت سال گذشته به روش DSAS است. از این رو، داده‏های دبی و رسوب رودخانه اروند، باد، موج، جریان دریایی، و نوسانات جزرومد همراه عکس هوایی، نقشه توپوگرافی، و تصویر ماهواره‏ای چندزمانه ابزار و داده‏های اصلی این پژوهش را تشکیل داده‏اند. با استفاده از تکنیک سیستم تحلیل دیجیتالی نوار ساحلی (DSAS) ، میزان جابه‏جایی‏های خط ساحلی (1955-2016) در نرم‏افزار Arc GIS استخراج شده است. نتایج نشان می‏دهد بیشترین میزان جابه‏جایی به صورت پیشروی خط ساحلی به‏ویژه در دهانه رودخانه اروندرود بین سال‏های 19551973 رخ داده است. بررسی روند تغییرات دبی آب و رسوب ایستگاه‏های هیدرومتری حاکی از ارتباط مستقیم میزان پیشروی و پسروی‏های صورت‏گرفته با افزایش و کاهش نرخ تراکم رسوب وارده به مصب اروند بین سال‏های 19682011 بوده است. همچنین، مشخص شد که عامل اصلی تغییر شکل تحدب مورفولوژی خط ساحلی به سمت غرب در مقیاس محلی نقل و انتقال جریان رسوب توسط جریان‏های دریایی و در مقیاس منطقه‏ای از جریان‏های متاثر از نیروی کوریولیس تاثیر پذیرفته‏اند.
    کلیدواژگان: : خلیج فارس، دلتای اروندرود، سیستم تحلیل دیجیتالی نوار ساحلی (DSAS)، هیدرودینامیک ساحلی
  • حمزه احمدی، زهرا علی بخشی ، محمود احمدی ، عباسعلی داداشی رودباری صفحات 353-372
    هدف از این پژوهش پایش دمای هوا با رهیافتی آماری بر اساس برون‏داد پایگاه داده بازواکاوی‏شده (ECMWF) نسخه ERA Interim برای دوره زمانی 19792015 با تفکیک مکانی 125/0×125/0 درجه قوسی و هم‏سنجی آن با پایگاه ملی اسفزاری و پیمونگاه‏های همدید کشور است. از سنجه‏های RMSE و R2 برای اعتبارسنجی نتایج و از بعد فرکتالی برای دگردیسی زمانی استفاده شد. نتایج اعتبارسنجی پایگاه ECMWF نشان‏دهنده توانایی و دقت زیاد آن در برآورد دمای هوا بوده است. هم‏سنجی پایگاه ECMWF با پایگاه ملی اسفزاری و پیمونگاه‏های همدید از نتایج مطلوبی برخوردار است؛ این نتایج در شش‏ماهه دوم یا نیمه گرم سال، به سبب تباین کمتر دمایی، از نتایج بسیار مطلوب‏تری برخوردار است. بعد فرکتالی دما در دوره گرم سال (دارای دگرگونی کوتاه‏مدت) افزایش‏ یافته و در دوره سرد سال (دارای دگرگونی بلندمدت) کاهش یافته است. توزیع فضایی دمای هوا نشان داد در ایجاد الگوی دمای هوا در بام ایران عامل عرض جغرافیایی بیشترین نقش را ایفا می‏کند. کانون گرم‏ترین نواحی در مناطق کویر لوت، جنوب‏شرق، و نوار جنوب کشور است. مناطق خنک و سرد نیز منطبق بر نواحی مرتفع و پیکر‏بندی ناهمواری‏های بام ایران است.
    کلیدواژگان: ایران، بعد فرکتالی، پایگاه داده بازواکاوی‏شده، دمای هوا، _ ECMWF ERA Interim
  • مهران حیدری بنی، حجت الله یزدان پناه ، عبدالمحمد محنت کش صفحات 373-389
    برای مطالعه اثرات اقلیم و تغییرات آن بر تولید محصولات کشاورزی، از تلفیق مدل‏های گردش عمومی جو و مدل‏های آب و هوا-محصول استفاده می‏شود. در این پژوهش ضرایب مدل APSIM برای شبیه‏سازی عملکرد و مراحل فنولوژی کلزا واسنجی شد و به منظور بررسی اثرات تغییر اقلیم از فراسنج‏های اقلیمی ریز‏مقیاس‏شده مدل دینامیکی NOAA-GFDL استفاده شد. نتایج نشان‏دهنده آن است که با سناریوی RCP8. 5 مدت زمان مراحل فنولوژیکی سبزکردن، گل‏دهی، غلاف‏‏بندی، و رسیدن و با سناریوی RCP4. 5 مراحل گل‏دهی و غلاف‏بندی کاهش خواهد داشت و بیشترین میزان کاهش در دوره گل‏دهی با سناریوی RCP8. 5 دیده می‏شود. با این سناریو دوره رزت 10 روز و با سناریوی RCP4. 5 این دوره 9 روز طولانی‏‏تر خواهد شد. پیش‏بینی می‏شود میانگین عملکرد کلزا با هر دو سناریوی مورد مطالعه تا 6/18درصد افزایش یابد. چشم‏انداز افزایش عملکرد کلزا در استان چهارمحال و بختیاری بیانگر آن است که این منطقه تا افق 2030 از استعداد مطلوبی در کشت و توسعه این محصول برخوردار خواهد بود.
    کلیدواژگان: آپسیم، تغییر اقلیم، چهارمحال و بختیاری، عملکرد، فنولوژی، کلزا
  • سعید صالحیان، عبدالرضا رحمانی فضلی صفحات 391-406
    حوضه آبریز‏ زاینده‏رود در منطقه مرکزی ایران از مناطقی است که دارای مسئله ناپایداری منابع آب است. در این پژوهش‏ با روش‏های تحلیل تغییرات کاربری ارضی، بررسی تغییرات بهره‏برداری از آب‏های زیرزمینی، و توزیع پرسش‏نامه‏ پیامدهای محیطی ناپایداری منابع آب در حوضه زاینده‏رود بررسی شده است. بر این اساس، تغییرات کاربری زمین بین سال‏های 1380 و 1392 و تحول چاه‏ها و سفره آب‏ زیرزمینی بین سال‏های 1385 و 1390 مطالعه شده است و، با توجه به ‏شدت بیشتر خشک‏سالی در پایین‏دست، ‏در سکونتگاه‏های روستایی محدوده پایین‏دست حوضه، پرسش‏نامه توزیع شده است. بر اساس فرمول کوکران، تعداد پرسش‏نامه‏‏‏ها از تعداد 33153 خانوار روستایی 380 نفر برآورد شده که، در طی تحقیق و بر اساس محدودیت‏ها و حذف پرسش‏نامه‏‏های نادرست، تعداد نمونه‏ها به 323 مورد رسیده و در تعداد 25 روستا توزیع شده است. نتایج پژوهش نشان می‏دهد ناپایداری منابع آب در حوضه آبریز‏ زاینده‏رود آثار محیطی نامناسبی دارد و پایداری حوضه را با خطر جدی روبه‏رو کرده است. تغییرات Land use حوضه نشان از دست‏اندازی گسترده فعالیت‏های انسانی در حوضه داشته و، از طرفی، با خشکی رودخانه، فشار بر سفره‏های آب زیرزمینی تشدید شده است. میانگین شاخص‏های پرسش‏نامه‏ پیامدهای خشک‏سالی نیز عدد 22/4 به‏دست آمده که نشان از وضعیت نامناسب شاخص‏های زیست‏محیطی در بخش پایین‏دست حوضه دارد.
    کلیدواژگان: پیامدهای محیطی، تغییرات کاربری زمین، رودخانه زاینده‏رود، منابع آب زیرزمینی، ناپایداری منابع آب
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  • Nasrin Abdolkhanian, Hiva Alamizadeh, Ali Dadolahi Sohrab, Ahmad Savari, Mohammad Fayaz Mohammadi Pages 207-219
    Introduction
    Rivers affected by erosion and sedimentation, which are subject to various changes, including changing the direction of transverse and longitudinal movements, the shortcuts, changing river bed elevation change, change, change size and geometrical properties route pointed. Erosion and sedimentation studies provide the opportunity to identify the behavior of river morphology, the effects of different measures to reorganize its behavioral performance evaluated on quantitative and qualitative data And thereby allows detection of unstable and applying measures to protect and advance engineering measures It was already possible. Arvand River is one of the most important navigable rivers in Iran, and it’s the most traffic place for oil floating which don’t have any system for delivery waste materials and discharging these waste materials in water making oil pollution. Arvand River vast river in southwestern Iran in the Iran-Iraq border and the connections of the dejle, forat and Karun emerged. This study range to which the mouth of the Arvand River in the northern part of the Persian Gulf to the middle of Abadan, about 48 km from the river encompass.
    Materials and methods
    In this research for simulating the way of diffusion of oil pollution in Arvand Rood the Arc GIS and surfer software and three dimensional hydrodynamic model (COHERENS) are using, has been employed to solve the equations of continuity and Navier-Stokes in three dimension as well as equations of salinity and temperature. Also for displaying data Ferret software is using. First the model is verfing by using field information and then the result are showing as different senarios for diffusion oil pollution. Including modeling, taking into account different rates for Arvand, spill pollution at different times of the tidal cycle, leaks in different areas and with different loss amounts to is the possible crisis management. In this study, three-dimensional hydrodynamic model of coherence, is used to simulate the flow velocity the Navier-Stokes equations in three dimensions and equations are solved transfer salinity and water temperature separation method. Boundary conditions applied، including changes in temperature، salinity and flow rate، temperature and salinity changes and apply for open border river and tidal components O1, S2, M2 and K1 open sea in the model used for the border. To create files bathymetric mapping of the Armed Forces of hydrographic maps in the scale of 1:25, 000 use software and GIS georeferenced digital interpolation were then. In this study, a computational grid of 80 x 83 meters with an accuracy that range in size 96/52 * 97/48 km covers. One of the most effective tools in the interval erosion and unsustainable use of aerial photographs. The aim of this study was to determine the scope of erosion and sedimentation in Arvand River is using GIS. GIS is a computer-based technology that uses geographic information systems as a framework for managing and combining data, solve problems and understand situations in the past, present and future uses. Software of GIS to identify areas of erosion and sediment has been used in Arvand River And also output the final maps with erosion and sediment pollution is classified.
    Results and discussion
    To show the flow rate in different parts of the river, three cross-section upstream, mid-stream and river mouth for the average speed for different times and different places been brought, According to the average upstream speed is observed that the flow rate of water flow rate on the beach on the coast of Iran is Iraq, In the middle sections of the river, the average flow rate on the coast of Iran, Iraq coast, at some point in the middle of the river mouth of the river can be seen that the average speed is lower and on both sides of the river. Because of Arvand River is a tidal river, when the diffusion of oil pollution happen in specified place in high tide, it polluted the outside areas of river, and when it happen in reflow it quickly reached to Persian Golf and controlling it become difficult. The accessible result, represent the effect of tidal on oil pollution diffusion.
    Table 1: different parts of the Arvand river coast erosion and sediment
    long range (%) long range (km)
    62. 57 45. 54 sediment on the beach
    26. 75 19. 47 Beach erosion
    10. 67 7. 77 Established beach
    100 Total
    Conclusion
    Most of the beaches in the study area are related to sediment The length of this range is 62 percent and more of beach fixed and erosion Due to the different horizontal sectioning to speed on the river, and the output flow velocity of the coherence we conclude Where the water flow rate is high, more erosion, and where less water flow speed, sediment more. Where the sediment is covered zone is the highest pollution
    Keywords: Arvand River, Sedimentation, Coherence, Modeling, GIS
  • Mohammad Sharifi paychoon Pages 221-239
    Introduction
    Cryopediment and cryoplanation are created in arid and semi-arid regions. In according to studies performed around the world, they formed in the preglacial climatic condition. Cryopediments are very gently concave erosional bench-like landforms that are usually cut into the base of valley sides or marginal slopes of highlands and mountains (Czudek and Demek, 1970; Demek, 1972). Cryopediments developed by cryogenic processes in cold climates of the periglacial climate-morphogenetic zone, mostly with the presence of permafrost (Czudek, 2012). Cryopediments develop due to the activity of a range of cryogenic processes whereby frost action, nivation and other processes and cause to retreat back scarps. Cryoplanation terraces are bedrock steps or terraces on ridge crests and hilltops. The tread or “flat” area is 10 to several hundred meters wide and long and slopes from 1 to 5 degrees parallel to the ridge crests. Cryoplanation terraces exist in many parts of the world in present or past periglacial environments. They occur chiefly in nonglaciated regions and near the general altitude of snowline. Cryoplanation terraces form by scarp retreat as the result of nivation. Surficial debris is removed across the terrace tread by mass-wasting. Terrace morphology depends mainly upon climate, bedrock type, and terrace orientation. The aim of this research is studying of periglacier landforms especially cryopediments and cryoplanation in Tange-Chenar Catchment located in the south of Mehriz city in the Yazd province. The study region is located in the west slopes of Shirkuh mountain with more than 4000 meters high between 31° 18´ to 31° 26´ of northern latitudes and 54° 18´ to 54°29´ of eastern longitudes.
    Material and
    Methods
    This research has been performed on basis of field studies and direct observation of the basin landforms. Therefore we visited the area in tow time periods involving 13/11/2015 and 30/9/2014. However, we studied topographical and geological maps, and DEM for the study area at first. Therefore, the resulted information of the maps controlled with GPS System in the field. For knowing morphology of landforms and the role of lithology in their formation, we drew geological and geomorphological maps. In addition, for studying effects of climate on the formation and development of the landforms, we evaluated climate data, especially temperature parameters in the past and present time. Thus, we drew isotherm map for cold season using temperatures data of 8 station for 14 years. Also, because of the constituent of the landforms have been created in the Pleistocene, we reconstructed temperature data foe that time using snowline and equilibrium ice-water line and drew isotherm map for that time.
    Results and Discussion
    The study area from ground morphology and facies point of view is divided into four categories includes mountain, hill, slope terraces and pediments. Finding showed that the pediments in the region are different from warm arid and semiarid region known in the world. Although, both of them have similar morphology with the same slope about less than 12 degrees. But, they have some significant differences. For example, the cryopediments in the study area have created and developed as a result of the side valleys. Besides, deposits that cover the surface of cryopediments are not alluvial. While, pediments covered by alluvial sediment and formed due to surface water and floods. Also, on some slope can be seen one or two and sometimes three terraces which have relatively flat surfaces. The slope of their surfaces are often less than 5 degrees. Thick sediments and sometimes suitable soil have covered their surfaces. So, on some of them have been created gardens and farms. The width of the terraces varies between 10 to 100 meters. Some of them are still in developing. Most of the surfaces has located above 2000 meters. Thus, on any of these landform are not alluvial deposits.
    The studying of climatic parameters shows that these landform must currently being developed. According to, we drew an isotherms map for cold season of the year. The map indicate altitudes above 2000 meters have periglacier condition especially in the cold season. Reconstructed temperature of Pleistocene period also showed that periglacial morphoclimatic system has been dominated on the most of the study area. The system has provided favorable context for physical weathering of granites and conglomerate which had formed most of the outcrop stones. Then, periglacial processes such as creep frost, nivation, congelifluction, rill erosion, dell formation and etc. caused the formation of landforms and retreating the slopes.
    Conclusion
    Cryoplanations and Cryopediments are Quaternary landforms developed in the cold periods of the Pleistocene. Processes responsible for carving cryopediments were frost creep, frost heaving, nivation, congelifluction (solifluction over the permafrost table), rill erosion, piping, dell formation (dells acted as main lines of material removal) and backwearing of the back slope (Demek, 1980). Although, the morphology of cryopediment is similar to pediments in arid and semiarid region. Aridity in both environments influences weathering and slope processes, which results in similar landforms. But they create in different condition and different processes. Pediments create by surface water processes especially sheet washes. While, cryopediments and cryoplanations formed with permafrost processes. Therefore, their sediments are not alluvial. However, cryoplanations are the landforms that create in periglacier morphogenetic system with the context of stones outcrope of special. These stones in the region have been granites and conglimerates.
    Keywords: Tange-chenar Basin, Preglacier, Cryopediment, Cryoplanation, Cryogenetic
  • mahtab alimoradi, Mohammadreza Ekhtesasi, Mehdi Tazeh, Haji Karimi Pages 241-253
    Introduction
    Fractal analysis is one of the quantitative modeling of river networks. By determining the fractal dimension of linear structures such as faults, canals, and meandering river paths, one can estimate many of their features (Turcotte D.L. 1992). Fractal of figure, is a component with static geometric patterns that illustrates the general pattern of a phenomena. The first studies to create quantitative, mathematical, and geometric proper models from river network were made by Horton in 1932 and 1945, yet the study of relationship and comparison quantitative parameters with fractal geometry goes back to the last two decades.
    2. Study area
    The study area consist of 12 watersheds –Holeylan, Doyraj, Tangesazbon, kolm, NazarAbad, Jezman, Vargach, Chomgez, Chaviz, Siagav, JafarAbad, and Ema– from Ilam Province. Table 1 showed that the formation of study area.  
    Table1 the details of formations in the study area.
    Formation name Symbol Lithology Sensitivity to erosion of 10
    Quaternary Qal Alluvial deposits of the platform 1
    Quaternary Qt Alluvial fan 5
    Aghajari Aj Sandstone – marl – sandy limestone - conglomerate 6
    Gachsaran Gs Marl – limestone marl 3
    Asmari Sb Karstic limestone - dolomite 9
    Pabdeh Pd Mliky gray shale and marl with limestone 7
    Kashkan Kn Conglomerate and sandstone and siltstone red 9
    Ahak Tele Zang Tz The average white to cream-colored limestone marl layers 9
    Amiran Am Siltstone and sandstone olive to dark brown color 7
    Ahak Imam Ehm Rifi fossils of cream-colored limestone with interlayers of Chile 8
    Sarvak Sr Thin layer of limestone 9
    Ilam Il Medium to thin and milky gray limestone layer 7
    In table (1) by increasing the numerical value of resistance degree, the formation sensitivity to erosion is reduced. (Rosovski van Voyk, 1992).
    In FayzNiya’s classification (1995) which is based on Rosovski’s classification, rocks with greater resistance have higher value (max 20), and rocks with lesser resistance have lower value (min 1). Therefore, resistance range to erosion of the existing formations in the study areas can vary from 1 to 9.
    3. Research
    method
    Extraction of drainage network via Arc GIS
    These networks were provided based on 50 DEM coordinates that in many cases, there isn’t enough accuracy and some channels are not displayed. Therefore, after transferring data to Google Earth, it was fully matched with the natural drainages and with a 5-meter accuracy, hydrographic network map was drawn and completed to reflect the full details of the network.
    Thence one cannot scale maps via “Fractalys”, fields with the same space of 25 kilometers on similar formations in different areas were accidentally chosen via “Fish Net” –in Arc GIS, to fix this problem. For each study formation, three 25sq.km. Fields were chosen and by the accuracy of 5 meters. These maps that had the same drawing accuracy and space, were drawn in the same scales via GIS on an A4 page in “.bmp” and then were brought to Fractalys and finally, their fractal dimensions were calculated and extracted by the geometric method of counting boxes.
    4. The
    results and discussion
    The results show that a canal with an accuracy of 50 DEM meter on corresponding 5x5sq.km. plots, has much less accuracy than 5 meters in comparison to the drainage network drawn via Google Earth with less than a 5-meter accuracy, and in formations that are sensitive to the formations which are resistant to density changes of the hydrographic network, and have more changes in their fractal dimension as a result.
    Google Earth images below are the examples of 25-kilometer areas which their hydrographic networks were revised.     Quaternaryn Gachsaran
    Fig 6 modified hydrographic network of 25 km in Google Earth
    Fig (6) Regression numeric index to erosion resistance (Sf) and formations fractal dimansion (Fr) after modification of 25 km units
    In Fig (6) the amount of R2 is 0.9742 and shows the high correlation and significant relationship of fractal dimension to numerical index for resistance to erosion. by increasing the resistance of the formaion, numerical value of fractal dimension will be decreased.
    Table 3 showed that statistical analysis between SF and FR.   Table 3 formations resistance data correlation (from 20) (Sf) and fractal number (Fr) of formations after correcting the 25-kilometer units in them.
    Fr Sf
    -965.0 000.0
    12 1
    12 Sf Pearson
    Correlation
    Sig. (2-tailed)
    N
    1
    12 -965.0 000.0
    12 Fr Pearson
    Correlation
    Sig. (2-tailed)
    N
    Table (3) shows the amount of data correlation (-965). Their amount would always be between the numbers +1 and -1. The more close its absolute gets to 1, the correlation will be higher, and the more close it gets to zero, the data correlation will get lower. (Ismayili and Kheyri 1385) As a result, there is a meaningful connection between formation resistant and fractal dimension. The minus sign indicates a negative data correlation (Afshani 1387).
    Table 4 Regression of the formation resistance values (Sf) and fractal number (Fr) of the areas after the 25-kilometer unit correction
    Model Summary
    Std. Error of the Estimate Adjusted R Square R Square R Model
    0.05116 0.924 0.931 0.965a 1
    .
    In the table above, “R” is the correlation intensity and its value are always between zero and +1 and “Square” is the coefficient of determination. The more closer “R” value gets to 1, the higher the correlation is between two variables. Therefore the number 0.965 illustrates high correlation of the formatuion resistance and its fractal number.
    Total
    Results
    The results show that between the fractal dimension and hydrographic network, there is a significant and negative correlation. The highest amount of fractal dimension in study areas is for the Quaternary formation of granule, equals to 1.65, and the lowest numeral amount of fractal dimension belongs to “Sarvak” formation –equals to 1.06.
    Also in formations with greater sensitivity than resistant formations after the correction of the hydrographic network via Google Earth, more changes occurred in the hydrographic network congestion, thereupon their fractal dimension change is also observerd more
    Keywords: Fractal Dimension, Hydrographic network, Geological formations, Ilam
  • mohammadreza mahboubfar, Mohammad Hossain Ramesht, Hojatollah Yazdanpanah, Mehri Azani Pages 255-270
     
    Introduction
    Air inversion is a climatic phenomenon causing increasing in the aggregation of pollutants in highly populated and industrial cities, such that crossing from the air quality threshold would have extensive problems for the citizens. Attention of managers to this problem is mainly referred to polluting factors such as traffic. However, it should be seen that in case this phenomenon exists during all the seasons and if the polluting factors have no great changes during the year, what factor can lead in crossing the air quality index from the threshold value, and, will there be an approach for reducing the continuity of this situation, if continuity of the inversion leads to such a condition?
    The main problem in this study is whether there is the possibility of managing Esfahan air pollution in such a way for the atmosphere pollution density not to tend towards the critical threshold. In case the answer is positive, how can a model be presented for controlling the air pollution crisis threshold by relying on the climatic management?
    Materials and Methods
    The research method in this paper is mainly relying on an analytical method and depends on the principles of interpreting climatic and atmospheric pollutants data. The subject of air pollution critical thresholds is considered for approaching the research aims. Thus, the used data were related to a 30-year data (1985-2015) from Meteorological Organization and balloon data including pressure, temperature, speed, wind direction, and rains, and the air pollution data were from 14 pollution measurement stations belonging to Esfahan Environmental Organization. The analyses in various levels enabled us to find out about the inversion conditions in different levels. Hence, only the 1670, 1680, and 1860 m levels were selected due to formation of pressure and temperature closed cells among one hundred produced weather maps. Then, the cellular excitation index (C.E.=f/k) was calculated, where k= D/(Δt,p) and “f” is the Newton mass, and the temperature and cellular pressure differences were calculated by using this formula. The two indices showed the conditions and possibility of excitation of temperature and pressure closed cells for reducing the continuity of inversion time.
    Results and Discussion
    Regarding the documentation data and extracted results, the inversion in the city of Esfahan was analyzed, and the intensity, continuity, and altitude of the inversion in various high levels were determined. Thus, the temperature and pressure inversion conditions were investigated for different levels with regards to the balloon data, and inversion analysis for different levels became possible according to temperature and pressure closed cells. The analyses included 100 maps from different altitudes that according to the analysis, the two 1670 m and 1680 m were for the temperature and the 1860 m level was for the pressure in the closed cells. In fact, the above altitudes were the levels having temperature and pressure closed cells with specific differences, providing the possibility of excitation. Afterwards, the excitation conditions were calculated by calculating the cellular excitation index.
    Conclusion
    Statistical analysis of the obtained information from the balloons and atmospheric profile indicate that the inversion phenomenon in Esfahan region occurs in different days of the year, and the considered point regarding the research questions is the continuity of inversion time. In other words, inversion phenomenon may not be considered as the main factor in emergence of pollution crisis, but the continuity of this of this condition is the factor for increasing the density of atmospheric pollutants and crossing from critical threshold (AQI 150). Hence, it can be stated that continuity of inversion condition leads to exceeding of the pollutants density from the permissible range.
    It can be concluded from the statement that occurrence of atmospheric pollution condition can be prevented by two different
    methods
    Reducing inversion continuity
    Management of urban pollutants
    Thus, the following statements can be considered as the achievements of this study:In the most intensive dominating days of air inversion, pressure and temperature cellular nuclei provide the possibility to manage the continuity duration of air inversion by exciting the cells
    Regarding the intensity of inversion phenomenon exceeding quality index from the permissible range can be avoided in November and December by controlling the inter-city traffic control, and in January by controlling the industrial pollutants
    Threshold control models for November, December, and January in multiple basis are as follows: - General model for November includes:A.P.C*isf.Nov = (C.M**) V (U.M***)
    A.P.Cisf.Nov = (C.E****) V (C.CO or C.SO2)
    A.P.Cisf.Nov = (C.E) V (C.NO2 or C.O3) *Air Pollution Control
    ** Climatic Management
    *** Urban Management
    **** Cell Excitability - General model for December includes:A.P.Cisf.Dec = (C.M) V (U.M)
    A.P.Cisf.Dec = (C.E) V (C.CO or C.SO2)
    A.P.Cisf.Dec = (C.E) V (C.NO2 or C.O3) - General model for January includes:A.P.Cisf.Jan = (C.M) V (U.M)
    A.P.Cisf.Jan = (C.E) V (C.CO or C.SO2)
    A.P.Cisf.Jan = (C.E) V (C.NO2 or C.O3)
    Keywords: Isfahan, Air Inversion, Air Quality Index(AQI), Threshold
  • Abolghasem Goorabi, Vahid mohammadnejad Pages 271-291
     
    Introduction
    The active deformation in Iran is caused by Arabia- Eurasia convergence. This agent creates morphotectonic landforms in each part of Iran. The importance of understanding the tectonic regime in the direction of morphotectonic studies of each district, and the potential hazards of land area and thus make their management and preventive measures necessary to reduce their effects on the role of human structures. In the in most studies related to the recognition of the status of the first step in the morphotectonic region, paying special attention to the superficial geomorphic evidence and linear, then the data of Geophysics supplement and seismicity region. The evidence of active tectonic regime in the dominant understanding of the tectonic and mechanism of folds – fault is extremely helpful to identification of it. Study the evolution of the Quaternary, including geometric geomorphologically drainage action; and alluvial fans are factors that can help them to the position of the land area of each area. In this study, try to study active tectonic marker and landforms with evidence reviews and located in median of Shotori Mountains and Tabas Playa, landforms and evolutions of them by recognizing of deformation and stream patterns. In this study Folds, alluvial fans, earthquakes, faults, streams and cliffs has been studied.
    Method and materials
    In order to study area, we use remote sensing capabilities such as; sentinel, landsat 8, Quickbirds and DEM30m to recognize the structural of surface landforms (alluvial fans, folds) and lines (drainage networks, rivers, faults, cliffs). Following, we used ENVI and ArcGIS softwares to detection and drawing of maps. We used seismic data of Institute of Geophysics (2006-2016) and USGS (1900-2016). Finally, the geometric display of their displacement was done in Focal Mechanisms.
    Discussion and results (Evidence of active tectonics)
    Alluvial fans;
    The study of satellite imagery and geological maps of the area, especially in the west of the Shotori Mountains, reveals large and numerous alluvial fans, sometimes created to the desert along the lower sections and developed and expanded by the sedimentation of seasonal and permanent rivers. These alluvial fans are joined in most parts of southern Tabas. According to the criteria for the differentiation of alluvial fans from each other, three types of old, active and midway are identified at the confluence of the Tabas playa and Shotori Mountains as continuous.
    Folds and antecedences;
    There are several new folds in quaternary sediments in median of Shotori Mountains and Tabas Playa. One of them cases is Tabas (or Sardar) fold in north of Tabs city. This fold appearance among the old alluvial fan Tabas and Sardar River excavated hardly it. As Sardar River make a deep gorgeous (canyon) through this fold. Another folds like Tabas fold are; Fahlanj fold, north Fahlanj fold, Fosha fold.
    Cliffs;
    The origin of the cliffs or tectonic cliffs of the study area are the strike slip and reverse faults. As Tabas fault cause sever cliff more than 100 meter by North-South direction.
    Faults;
    Faults are important tectonic elements in the creation of various early landforms such as Horst, Graben, Thrust, etc. more of faults in the study area to follow Nayband fault system N-S direction. In the center of the fold east of the village of Estahpak, there is an active strike-slip fault series that displaces sandstone and conglomerate sediments of Miocene up to 130 meters. Estahpak fault and its lateral branches in some cases displaced the Quaternary sedimentary layers up to 330 meters. In Fosha fold, strike slip displacement Quaternary up 350 meters.
    Stream and rivers (Drainages networks);
    Stream and rivers are so sensitive to tectonic and response to it quickly. Straight Right Stroke Fault Estahpak causes displacement of streams up to 390 meters.
    Geophysics;
    According to seismic data from the US Geological Survey, from 1973 to 2016, about 60 earthquakes ranged from 4.5 to 7.4 magnitudes has been occurred. Meanwhile, the average depth of earthquakes is at an approximate depth of 31 km, which is the earthquake centers between depths of 58 - 2 km. The focus of earthquake centers at the beginning of the mountain front and immediately after the occurrence of roughness. In 1979, after the Tabas earthquake, a fracture with a length of 80 kilometers along the Tabas fault was created and killed more than 25000 people by 7.6 magnitude.
    Conclusion
    Indications of active, fault-driven folding and drainage incision, fans and cliffs are present in the landscape in Tabas. The morphotectonic and geomorphologic evidence of the Tabas area indicates the strong impact of ground forces building on surface landforms such as; alluvial fans, folds, stream and rivers, cliffs, faults. The effect of the new tectonic forces on the alluvial fans is the formation of a multi-stage convex alluvial fans or, in other words, three layers in the southern slopes of Tabas, and the growth of the folds. The anticlines are also other morphotectonic evidence in the Tabas area. The superficial and linear morphotectonic evidence in Tabas indicates the high tension and the strong dynamics of ground forces, as well as the existence of faults with thrust, strike slip, and hybrid mechanisms. Overall, the aggregate evidence also suggests that the tectonic forces of the eastern Playa Tabas are more active than the western highlands section. The presence of fans, faults and anticlines in the eastern part of the Tabas playa is due to this.
    Key words; Tabass, Active Tectonics, Morphotectonic, Quaternary landforms
    Keywords: Tabass, Active Tectonics, Morphotectonic, Quaternary landforms
  • Hesam Ahmady, Birgani Pages 293-305
     
    Introduction
    Over the last decades, sediment fingerprinting technique against the experimental models for erosion and deposition processes is now routinely used for its higher reliability and lower uncertainties. Its reliable information give the best indication of sediment yield produced by spatial sources of a catchment and let authorities know how take conservative operations and proper actions across the catchment to stop the soil erosion. Therefore, identification of the dominant processes and sources generating the sediment within its catchment are vital. The western shore of the Lake Urmia, NW Iran, the world’s second largest hyper-saline lake has now retreated more than 7 Km from the shore and across its western margin, sand dunes and sand ridges have been appearing. Finding out the geomorphological/lithological units as the sediment feeders out of its western catchment using geochemical data was done. As the main aim of the present research, need to correction factors including particle size, organic matter and tracer discriminatory weighting was applied in recognition of potential changes in fingerprint properties during sediment delivery.
    . . . . . . . . . . . . . . .
    Material and
    Methods
    The mixing model algorithm was used to estimate the relative contributions from the potential sediment sources by minimising the sum of squares of the weighted relative errors. OF=∑_(i=1)^n▒0((S_Sink-(∑_(j=1)^m▒〖S_Source .P_s.Z_s.O_s)〗)/S_Sink )^2 W_i
    0≤P_S≤1 ∑_(j=1)^m▒〖P_S=1〗
    SSink: concentration of fingerprint property (i) in the sediment collected from the outlet;
    PS: the percentage contribution from source category (s);
    SSource: mean concentration of fingerprint property (i) in source category (s);
    ZS: particle size correction factor for source category (s);
    OS: organic matter content correction factor for source category (s);
    Wi: tracer discriminatory weighting;
    n: number of fingerprint properties comprising the composite fingerprint;
    m: number of sediment source categories;
    . . . . . . . . . . . . . .
    The above algorithm has incorporated three correction factors to reflect the impact of element concentration in given sediment load size. The effect of the correction factors into the fluvial and alluvial sediment loads has been approved, what is has not been well understood for aeolian sediments and desert environments. Therefore, the role of the correction factors in estimation of proportion of each potentially sediment source is inferred. Paired t-student statistical method was applied to be seen whether differences between being of correction factors and not being correction factors is seen.
    . . . . . . . . . . . . . .
    Results and Discussion
    As the paired t-student method results show, there is not significant differences between the source contribution before using the correction factors and after using the correction factors. But it is an statistically result and mixing model or objective function results has another story. According to Table 2, before using the correction factors, Qmf and Qt geomorphological/lithological units with 47.76% and 52.24% have the highest proportion in generating the sediment load of the catchment respectively. After implementation of the correction factor, Qf and Klshi geomorphological/lithological units with 67.5% and 32.5% have the highest contribution respectively. So, different source proportion was seen with no significant statistic results.
    . . . . . . . . . . . . . . .
    Conclusion
    The present research successfully interpreted the impact of correction factors on sediment source contribution of the Lake Urmia sand dunes. These correction factors are now widely used into the mixing model or objective function to improve the comparability of source and sediment samples. It is inferred the organic matter correction factor could have used while mineral-magnetism properties of samples are known as the tracers. The particle size correction factor due to its strong influence on many of the tracers used for fingerprinting is applied, when the relation of grain size to each tracer's concentration is tested. With generating a scatter plot of particle size or organic matter content against tracer concentration for each source group, necessity of correction factor is evaluated. Generally, it is interpreted applying the correction factors is vital when some other parameters including sediment environments, tracer properties, chronology of sediments, particle size of sediment loads etc. is preliminary evaluated
    Keywords: Sediment source fingerprinting, Correction factors, Sand dunes, The Lake Urmia
  • Leyla Goli Mokhtari, fereshteh beiramali Pages 307-322
     
    Introduction
    In recent decades there has been an increasing interest in the earth natural events and this has led to the development of three concepts in the world of science. Geodiversity, Geotourism and Geoconservation. “Geodiversity” can be defined as the natural range (diversity) of geological (rocks, minerals, fossils), geomorphological (land form, physical processes) and soil features. It includes their assemblages, relationships, properties, interpretations and systems.
    There is as much geodiversity in the world as biodiversity. Geodiversity and biodiversity are concepts that evolved from the World Biodiversity Convention, in 1992, in Rio de Janeiro, Brazil (Rio-92). Serrano and Ruiz-Flaño (2007) and Serrano et al. (2009), through detailed geomorphological survey, applied the calculation of the spatial distribution of geodiversity in Spain, based on the study of a wide set of mapped elements of geomorphology, geology, hydrology, soil, and active processes.
    Zwoliński and Stachowiak (2012) carried out research on geodiversity in a protected area that also served as touristic attraction. The evaluation carried out based on some elements such as waterfalls, according to their size, kinds of rocks, cavities (according to their size), shapes of land, slopes, presence of lakes, altitude, watercourses on cliffs, soil, and geoecological structures. Instead of a variety of elements, the applied method was based on an algebra of maps, as elements were given different scores. The authors concluded that mountains with steep cliffs are more geodiverse areas. Manosso & Nóbrega (2015) calculate and analyzed the distribution and the diversity of abiotic elements in landscape units. The sample units were compared according to geological, geomorphological, hydrographical, and pedological elements, as well as land use and habitation.
    Haririan (1990) was the first one presented a definition of geodiversity in Iran. In his view, the formation of geological diversity depends on the internal and external processes diversity. Sepehr (2013) has expressed the natural hazards and geodiversity are paleogeomorphological evidence. As the geodiversity has been affected by complexity of process and time, he has presented a geo-system analysis. Ba-tajrobe et al. (2016) have offered the geodiversity map of Mashhad city based on the analysis of landforms sensitivity to erosion and weathering.
    This work aimed to perform a quantitative evaluation of geodiversity in 3 unit of Eshtehard County, on the southern part of Alborz province.
    Materials and methods
    In this study, 1:50,000 scale topographic maps, 1: 100,000 scale geological maps, Googlearth satellite images, Digital Elevation Models (DEM), Geographic Information System (GIS), library studies and field observations were used. To check the type and distribution of geodiversity elements in the study area, the following five steps were performed:The study area was determined using maps and satellite images.
    Geomorphological units based on the three units of landscapes including plain, hills and mountains were determined.
    Ground elements in the region, using satellite imagery, topographic maps, geological maps, soil maps, hydrographical maps and field observations were identified.
    Required maps using GIS mapping and photographs of the field works, prepared and evaluated.
    Geodiversity index was calculated for each unit and comparative analysis was performed.
    In order to evaluate geodiversity condition in studied are, geodiversity index (Serrano and Ruiz-Flaño, 2009) was used.
    GD= (Eg.R)/(Ln S)
    GD Geodiversity index
    Eg Number of abiotic elements
    R Roughness of the relief
    Ln S Log of the sampling area
    Index (R) was calculated using the topographic relative position method in and GIS and was placed in Formula 1.
    The final step is presentation of the concept of protection and maintenance conditions in the study area.
    Results and discussion
    Abiotic elements diversity in Eshtehard is not only in terms of geological diversity but also in terms of covering the soil, hydrological conditions and landform.
    Eshtehard playa is an evidence of environmental changes during the cold periods of Quaternary. According to previous studies, it has been an old lake bed during quaternary. Salt River, in this context, is ongoing and will eventually it connects to Hoz-e-Sultan lake.
    Rainbow-colored hills in north of the Eshtehard are one of the most remarkable landscapes in the region. There are a seasonal lake within colored hills, salt cave and two different springs that are geodiversity features in the hills. The marl hills and Stone houses in the northwest of Eshtehard, are another perspectives of the unit G1.
    South of the Eshtehard is surrounded with Halqe-dar and Tavreh mountains. The maximum height of the mountain is 2,000 meters above the sea level. The important differences in unit G3 rather than G2 and G1 are numeral springs and variable volcanic stones.
    The highest (R) is related to unit G1 with the 0.4745 GD. Most of the abiotic elements are in G3unit (60 elements) and the least are located in G1 (30 elements).
    After calculating the parameters, we realize that the greatest geodiversity index is belonged to G3 (4.716) in the South of Eshtehard area. This is because of high level of diversity in hydrologic and lithological elements.
    Finally, because of importance of abiotic phenomena in studied area and high level of geodiversity, geoconservation activities is necessary for valuable land resources; furthermore the capacity of geotourism must be evaluated and managed
    Keywords: Eshtehard, Geoconservation, Geodiversity, Geotourism, Landform
  • arash zandkarimi, davod mokhtari Pages 323-338
     
    Introduction
    Environmental management requires continuous spatial information of the environmental variables. However, many of these data are taken discretely and point by point. Therefore, the methods to convert point data to continuous data have become indispensable tools (Lee et al., 2014: 173). The spatial interpolation makes able the conversion of point data to area data (Chang, 2004: 275) by predicting the values of a main point variable in the sample area (Barov and Daniel, 1998: 244). There are different algorithms for spatial interpolation (Faraji Sabokbar and Azizi, 2006: 1), which generally fall into two deterministic and geo-statistics categories (Mir Mousavi et al., 2009: 107). In deterministic methods (Inverse Distance Weighting (IDW), Radial Basis Function (RBF), and so on), interpolation is done according to the level of the sampling points and similarities. However, geo-statistical methods (Kriging) of spatial correlation quantity consider sampling points, and estimates based on the location of the non-measured samples (Taze et al., 2008: 8).
    Materials and Methods
    In this study, in order to assess the accuracy of the various interpolation methods to estimate the rainfall distribution of Kurdistan Province, pluviometry stations, synoptic, and climatology data were used. After reviewing the statistical situation of the stations, statistical period of 2001-2013 has been selected, and among all stations in the basin, stations, which had had 12 years of full or recyclable statistics until 2013 were selected for the study. It must be noted that the selection of the stations was according to their statistics rebuilt, by the application of the highest correlation with the adjacent stations method. Finally, data quality and data sets normality were recorded, and were evaluated by using Komogorov-Smirnov and Chi square X2 statistical tests. In addition, the digital elevation model data, collected by the SRTM satellite sensors with spatial resolution of 30 m, as well as analytic functions of the ArcGIS 10.2.2, Surfer 11, and IBM SPSS Statistics 22 software were used. After reviewing the data of the available stations (77 pluviometry stations, 22 synoptic and climatology stations of the Meteorology Organization, and 76 pluviometry and evaporation stations of the Department of Energy), according to the statistical course of the stations, and with regard to the missing rainfall data in the reconstruction, the least common period of it should not be less than 10 years (Sun and Patterson, 2006: 1990). The normality of the test data was done, and 145 stations were selected for analyzing of the interpolation methods, and choosing the best method. The methods used in this study were Inverse Distance Weighting, Spline (with Tension, Thin Plate and Completely Regular functions), Ordinary Kriging (with Circular, Spherical, Exponential, and Gussian functions), and Universal Kriging (with Rational Quadratic and Liner functions) are. Figure2 shows the steps of the study to select data and the most optimal method.
    Results and Discussion
    After depicting the spatial rainfall data, the normal distribution of them was investigated by Komogorov - Smirnov and Chi square X2. The results showed that the data distribution at the level of 95% has no significant difference with a normal distribution. In order to analyze the accuracy of the various interpolation methods, the models were implemented using the GIS Arc Software. By applying each of these models on rainfall data, the maps were obtained (Figure 5). In order to evaluate and determine the most optimal model, the validity and the accuracy of the maps were evaluated. As it mentioned in the previous section, the more the Mean Absolute Error (MAE) and the closer Mean Bias Error (MBE) to zero, the accuracy of the model is higher. On the other hand, the less the Root Mean Square Error (RMSE), and the higher the correlation coefficient (R2), the model error is less. Table1 shows the error rate of implementation of the interpolation methods. Based on the findings of the study, the lowest error observed belongs to the Ordinary Kriging Method of interpolation with the circular function. After that, it belongs to the General Kriging Method with the Quadratic Variogram. In general, the Kriging method provides a higher accuracy than the other methods.
    Conclusion
    In this study, the accuracy of the various algorithms was compared in the interpolation of rainfall distribution in Kurdistan Province. To compare the actual results, the same conditions were used to assess the accuracy. Then the most important methods of the validity were extracted and identified: Mean Absolute Error (MAE), Mean Bias Error (MBE), Root Mean Square Error (RMSE), and correlation coefficient (R2). Ordinary Kriging Method of interpolation with the circular function had the highest accuracy compared to the other methods (Table 1). One of the most important factors to achieve high accuracy in this method is its ability to depict the non-bias linear estimation. Of course, other methods, especially the Universal Kriging with Quadratic function, due to the use of local procedures offers an acceptable accuracy
    Keywords: Evaluate the accuracy, Kordestan province, The estimated distribution of precipitation, Interpolation
  • Maryam Rahmati, Mojtaba Yamani, Raziye Lak, S Shayan, Manuchehr Farajzadeh Pages 339-352
    A shoreline is defined as the line of contact between land and a body of water (Bird, 2011). The most effective processes on coastal morphology change are wind, wave, marine current, tides and human activity (El-Mrini et al, 2012. Moussaid et al, 2015). Prodelta of Arvandrud delta as the largest delta of the Persian Gulf, has very low slope in foreshore. Historical data of the last 60 years show the shoreline has been a lot of transgression and degradation. The aim of this study, is Evaluation of shoreline displacement rate and the factors affecting on its.
    Materials and methods
    In order to have an understanding of the effective factors on shoreline change, flow rate and sedimentary of Ahvaz (Karun) hydrometric stations statistics, area tidal data, wave rose, wind rose and current rose were processed. For determining the place and time changes in the shoreline, Cartosat (2011), Landsat (1973, 1982, 1994, 2002, and 2016) satellite imagery and aerial photographs (2016) were used. To calculate the rate of the shoreline changes, DSAS (Digital Shoreline Analysis System) method was used. In this article, upper limit of tidal zone (Diurnal) was selected as shoreline for all of time periods.
    Results and discussion
    Shoreline position in the study of periodic changes between the years 1955-2016 show shoreline has been progradation in the most areas. Increasing over 3.98 KM during the last 60 years indicates this sedimentation rate in shoreline. Shoreline progradation, has been notable at the mouth of the Arvandrud. Recent progress is related to the period 1955 - 1973. Relatively stable parts are most in the east of the area. These areas have been old mouths of Karun River, which has been now converted in to the estuary. The speed of dominant wind is 3/5 m/s and frequency is 62%. Since the direction of dominant winds of the region are northwest, wind factor can’t play an effective role on the shoreline morphology changes of this region. Dominant waves directions also are to the NW. 72% wave’s heights are between 0.02- 0.99 meters. Only affective waves in this area are waves with southwest and south east (diagonal) direction, which according to the frequency and less height wave and very low slope of the nearshore break farthest from the shore. Marine currents direction are NW-SE in this area. This current carries water and sediment of Arvandrud and Bahmanshir rivers from east to west. More than 51% of Marine flows have the velocity between 0-0.05 cm/s that can affect shoreline morphology. Studies show the level of the tide in this area of the Persian Gulf (except Khore Musa) reaches its maximum. Maximum and minimum height of sea water are 322 cm and 32 cm ,respectively that progress in land (backshore).To understanding the reasons of the shoreline progress, during dam constructing upstream of Karun river in Ahvaz, especially from 1975 until now, trend of water and sediment discharges into the mouth of Arvandrud has been gradually reduced. The years of 1973-1955, Karun River has experienced one of the high peaks of water and sediment flow to the Arvandrud, this has been coincided with the most shoreline progradation. An increase in the flow rate and deposition in this period correspond to the time with less number of built dams on the Karun River in comparison with the next periods.
    Conclusion
    Dynamic of water and sediment flow transport of Arvandrud to the shoreline, has been introduced as the main factor of propagation in this part of Persian Gulf shoreline. Delta-making process had been largest area between the years 1955-1973.This progradation has been associated with one of the highest peaks of water and sediment flow to Arvandrud. Marine currents (local scale) with direction of east to west and Coriolis factor with regional scale have had a major role and are responsible in shaping of shoreline convexity and development of spits to the west. The results of this study have been conformed more or less to findings of Yamani et al (1392) for the period 1977-2005 and Ranjbar and Iranmanesh (1390) for the period 1955-1992
    Dynamic of water and sediment flow transport of Arvandrud to the shoreline, has been introduced as the main factor of propagation in this part of Persian Gulf shoreline. Delta-making process had been largest area between the years 1955-1973
    Keywords: Arvandrud Delta, Persian Gulf, Digital Shoreline Analysis System (DSAS), Coastal Hydrodynamic
  • mahmuod ahmadi, abbasali dadashirodbari, Hamzeh Ahmadi, Zahra Alibakhshi Pages 353-372
     
    Introduction
    Air temperature is one of the most important climate measurements in the human environment, which directly affects the physical and biological processes of the ecosystem. Understanding this climate measure can be the basis for understanding many of the climatic processes, especially evapotranspiration (due to the climate of Iran). Reanalysis have been used in recent years in many studies, including studies on climate trends, climate modeling, and the assessment of renewable resources, and their high accuracy is confirmed.
    The present study aimed at evaluating the accuracy of the open-baseline base temperature data of the European Centre for Medium-Range Weather Forecasts (ECMWF) of the ERA-Interim version with a 0.125 × 0.125 arc-spatial resolution in a survey with observational data from the weather stations and the National Bassoon database has been designed and implemented. In this regard, the temporal and temporal changes of the temperature of the country were also evaluated.
    Materials and methods
    In this study, data from 32 weather observation pods during the statistical period of 1979-2015 were used to validate the ESFAZRI national Database. ERA-Interim, also produced by ECMWF, uses 4D-variational analysis on a spectral grid with triangular truncation of 255 waves (corresponds to approximately 80 km) and a hybrid vertical coordinate system with 60 levels. The ECMWF global model is used for the forward integration in the 4D-variational analysis and the temporal length of the variational window is 12 h.
    As stated for the validation of the temperature data of the ECMWF database of the ERA-Interim version, we verified the cells of this site with the data of the 32 well-selected Station in the period from 1979-2015. The nearest cells were selected to be sampled. To verify the two data sets, the R2 and RMSE indices were used. In order to evaluate the changes in Iran's monthly temperature, fractal dimension was calculated.
    Results and discussion
    The results of the validation between the European Centre for Medium-Range Weather Forecasts (ECMWF) and the ERA-Interim Emission and Interim National Projections for the period (1979-2015) showed that this base has a high performance, as is seen in most of the pioneering cases in this In the section, more than 98% of the coefficient of determination between the data of this base is observed with the data observed and recorded in the observer weather stations of the country. In the following summer, the fractal has reached its maximum value, reaching 1.63 in August for its grove over the year. Accordingly, the fractal dimension is increased and this increase reflects short-term variations, which means that the standard error also increases. In the cold period of the next year, fractals showed a decrease in value, reflecting short-term changes.
    In the cold season from December to March, the average temperature varies from 7.2 to 7.3. The minimum air temperature varies from -3 to -6 degrees, and the maximum air temperature varies from 21.4 to 23.0 degrees Celsius. The dispersion of the December temperatures is more than in January and February. The data distribution was observed positively in December, 0.51, January 0.41, and 0.30 in December. In the cold months, the temperature distribution is more than positive, in fact, the values are less than the average of a higher frequency.
    The average temperature in June was 28.2, 30 and 29 degrees Celsius, respectively. The range of changes in June, July and August was 22.3, 20.3 and 19.6 respectively, and the temperature diffraction in these months was 27.9, 20.19 and 18.4, respectively. The range of changes and dispersion in the months of July and August is higher than in September.
    Conclusion
    The purpose of this study was to evaluate the mean air temperature based on the ERA Interim version of the European Centre for Medium-Range Weather Forecasts (ECMWF) data model. The results showed that the model was able to measure the temperature in the long run. The average of air temperature in all months of the year with the spatial component of the latitude is the highest correlation coefficient. The fractal dimension of the air temperature in the cold months is less than the warm months of the year. The highest fractal dimension occurs in the months of July and August coinciding with the warmest periods of the year, which indicates short-term changes due to the stability of the systems in the warm period of the year and long-term changes due to the variety of macro-scale systems in the cold period of the year. This statistic for Iran's temperature has shown that the climate and, more specifically, that the study has been tied to it, temperature is a complex and non-linear system, and has been composed of different measures and interactions.
    According to the results, it can be stated that the southern regions of the country on the coast of Oman Sea and the Persian Gulf and the northern Persian Gulf in Khuzestan province require more attention regarding the days of cooling demand in the warm months of the year in order to adjust the air temperature in order to provide comfort in these areas. Should be. On the other hand, the pattern map for each month showed that the Northwest, high Zagros and Northeastern regions required more attention in terms of heating in the cold months of the year
    Keywords: Reanalysis database, ECMWF, Air Temperature, Fractal Dimension, Iran
  • Mehran Heidarybeni, Hojjat Yazdanpanah, Abdolmohammad Mehnatkesh Pages 373-389
     
    Introduction
    Climate has a key role in plant growth Therefore, it is clear that climate change will directly effect on sowing and harvesting of cultivate crops (FAO, 2013). Many scientists used APSIM to simulate the phenology and yield of canola. To understand the impact of climate change it is necessary to project the future climate based on different emission scenarios. These results must be combined with simulation models to predict crop yield and phenological stages. Assessment the impact of climate change on phenology and yield of agricultural crops in different regions show different results. The aim of this study was to investigate the impact of climate change on phenological stages and yield of Canola by APSIM-canola modules.
    Materials and methods
    Chaharmahl va bakhtiari in the southwestern of Iran is one of the main agricultural production zones is considered as the highest province of Iran. The soil physical properties were obtained from Agricultural Research center of Farokhshahr. Required meteorological data including precipitation, solar radiation, and daily maximum and minimum temperature were collected from 6 synoptic weather station in the study area. Data was used after quality control process. The meteorological data convert to compatible text format with APSIM.
    Biometric data and phenology:Canola has several varieties. Okapi is one of the winter varieties which was recommended for the study area. Agrometeorological data, including phenology and biometry from 2001 to 2010 were gathered and summarized. Includes the canola yield and phenological stages containing planting, germination, emergence, the first true leaf, rosette, stop the growth of winter, budding, stem elongation, flowering, pod, ripening and harvesting. Farm management information such as the amount of fertilizer, irrigation and frost and pest were also recorded. A total of 1700 reported of phenological stages was used over the 10 years of crop evaluation.
    Future climate data:Climate change data were downloaded from one of The World Climate Research Programme (WCRP) project so called Coordinated Regional Climate Downscaling Experiment (CORDEX). We used CORDEX MENA data in which the simulations were performed on a rotated grid with the pole at 180°W longitude and 90°N latitude.The domain covers roughly the region from about 27°W to 76°E longitude and 7°S to 45°N latitude. Simulations were carried out using two different resolutions: 0.44° (approx. 50 km) and 0.22° (approx. 25 km).
    Model Description:Agricultural Production Systems Simulator (APSIM) known as a highly advanced simulator agricultural systems in the world. There are 43 selectable varieties of spring and winter canola on APSIM v 7.7, but none of them cultivated in the study area. Germination, emergence, end of juvenile phase, flower initiation, flowering, grain filling and maturating are seven simulation of the phenological stages.
    Results
    For simulation of each phonological stage, elapsed time from sowing to the first day of reaching at each stage was counted. Water stress, nutrition, photoperiod, and vernalization have influence on the phenological stages (Zhang et al., 2014).
    Highest RMSE was calculated in the simulation of days after sowing to maturity (DTM) stage with 5 days and bias error was -0.7 days. Greatest bias error occurred in simulation of days after sowing to emergence (DTE). The correlation coefficient of the DTG and DTE was not statistically significant and this indicator in the other stages (P-Value = 0.01) is significant. The strongest correlation was obtained between observed and simulation of days after sowing to flower initiation (DTFI) and days after sowing to flowering (DTFL).
    Because of the crop management, soil and water conditions, simulation was done in three cases of poor, middle and high management. The RMSE in estimating of yield was 329.8 kg/ha which included 7.2% of canola average yield on study area. The rate of Bias error was18.2 kg and correlation between actual and simulated data were 0.96. We consider every year Farm management, nutrient and irrigation in the simulation and results showed that APSIM has reliability skill in simulation
    Based on scenario RCP8.5, considering : DTE, DTFI, DTFL, DTEGF and DTM stages will be reduce between 1 to 13 days the maximum reduction can be seen in the flowering and grain filling phases. However DTEJ will be raise and longer10 days.
    The results of data from RCP4.5 showed that DTFL and DTEGF stages, will decrease from 2 to 3 days, the greatest rate of decline was observed in the flowering period. DTEJ, DTFI and DTM stages will rise. DTFI and DTM stages will be increased up to 3 day. And similar to RCP8.5, DTEJ will be raised up to 9 days. It is expected that with RCP8.5 scenario the average of yield on the optimal nutrition and management will be increased around 18%. Whereas in poor management conditions the yield will be increased 18 and 13.6 percent respectively.
    RCP 4.5 in optimal nutrition and management will be inceased13.4% and in intermediate and poor management will raise around 14.3 and 13.6 percent. This suggests that without water limit, global warming will have a positive impact on canola yield in this area.
    Conclusions
    The study showed, APSIM could simulate the yield of canola with RMSE 320 kg/ha. Results showed that with RCP8.5, phenological stages including of DTE, DTFL and DTEGF and DTM will be shorten. with RCP4.5 phenological stages including of DTFL and DTEGF will be shorten The higher rate of decline was observed by RCP 8.5 scenario. DTEJ on RCP 8.5 and RCP 4.5 will be respectively longer 10 days and 9 days. It is expected that ,canola yield will be risen with both studied scenarios in optimum nutrition is about18%, in average more than 13 percent and on low nutrient up to 18 percent.
    Canola-Okapi yield increasing outlook in rejoin of Iran show a good potential on planting of this variety and this product will be develop on 2030 horizon
    Keywords: Canola-APSIM, Climate change, Chaharmahal va Bakhtiari, Canola, Yeild
  • saeid salehian badi, Abdol Reza Rahmani Fazli Pages 391-406

    1-Introduction
    Water is a major concern for sustainable development in the twenty-first century, as the experts in water issues will become the current crisis in the coming years a world war over water. Instability of water resources as drought or water shortage has affected many countries throughout history, especially the arid regions and has many damages and consequences in the economic, social and environmental aspects. Zayandeh-Rud basin in Iran central is region with water problems. Zayandehrood River that originates from the mountains Zardkuh Bakhtiary, Is the most important rivers of the region to develop of agriculture, and supply of industry and drinking water sectors and all of economic activities. Following Climate instability in recent decade and increasing pressure on river over time, is occurred Instability of agricultural water resources or droughts in recent years. In this research, is studied and compared the environmental consequences of water resources instability in the river basin, with use methods such as, the analysis of land use changes on two periods, Assessment of changes in the number of wells and the exploitation level of the underground water reserve and distributing questionnaires to analyze the effects indices of drought in the Downstream of the basin,
    2-Materials and methods
    In this research two methods are used, library research (book, papers, basic data collected from “National Forest and Land Organization” and “Iran Water Resources Management Co.) and field research (observation, interview with experts and Distribution of the questionnaire). Accordingly, investigated three methods the following:
    2-1- Change Detection of Land Use: All the basic data of this section are based on “Land Use National Plan” from the “National Forest and Land Organization”. In addition, the experts’ views were used in all the phases of the research. These maps were made between 2002 and 2013 and confirmed officially. The study target in this research is Zayandeh-Rud River Basin. Border of study area was specified with spot goals of research and views of experts. Then this border was mapped in “Google Earth” and the study area's border of research was extracted from basic map of National Forest and Land Organization of Iran”. Study area of research was divided into three section. Land use basic map in “National Forest and Land Organization” had twenty-two items that were merged and reduced to nine land-users. Change detection was done in Arc GIS software using Union program and exhibited the map, table and descriptive information.
    2-2- Changes of Underground Water: The basic data of this section earned from “Iran Water Resources Management Co. and Esfahan Regional Water Authority, and studied Changes in the number of wells, qanats and springs and removal level of the groundwater table and changes in reserve of groundwater aquifers in the Zayandeh-Rud basin in two statistical years 2006 and 2011.
    3-2- consequences of water resources Instability on environmental indicators:
    Statistical population of this section is villages in downstream part of Zayandeh-Rud basin. The population sample chosen based on Cochran formula and in the form of Stratified Probability sampling. Study Area in the down of the river (from Isfahan city to Gavkhoni marsh) is divided into two parts, Western and Eastern according to geographic, socio-cultural and political indicators; Then selected four districts in the ruling classes Research. From 33153 number of rural households Estimated 380 people to reduce 323 people during the study, due to the limitations and delete incorrect questionnaires, also estimated sample of settlements 25 villages. Questionnaires in the study area analyze and compare these indices in before and after the drought. In the following, analyzed average of research triple indices in SPSS software. Then result analyzed in one sample T-test and compared significant differences of Impact of drought in various rural districts with ANOVA test.
    3-Results and discussion:
    The comparison of land use map in 2002 and 2013 of total of study basin indicates that dry farming, agriculture, forest, residential settlements and marshland uses have increased while water surface, canebrake, and deserts as well as rangelands have decreased. Study of underground water indicate that after the water sources instability has increased level the exploitation of groundwater aquifers. It increased in the middle and downstream sections of basin that river's flow is not permanent, as has been offset water shortages caused by drought by drilling and exploitation water from wells. In this context, between 2006-2011 drilled 9277 number new wells. During these five years, added 4.8 meters depth of wells and groundwater level has dropped about 5 meters. Analysis of qanat Statistics indicate that due to droughts, drain the water qanats almost halved, and the number of springs also have declined. To assess the environmental effects of Water Resources instability is used 13 Index. The highest impact of drought on environment indicators is in "drying qanats, wells and springs", "reducing the amount of surface water" and "Increasing the depth of water wells (decline in groundwater levels)” and The least effect is seen on the Indicators: "increasing of fire in the natural environment of the region" and "Reduction of medicinal plants". The average of environmental impacts of droughts is 4/24. The results show that no significant difference between rural districts in study area in terms of the impact of drought; this means that the rural districts in study area are relatively similar to the impact of the negative consequences of drought in various aspects.
    4-Conclusion
    This process of development is dangerous for human and environmental sustainability in Zayandeh-Rud river basin. The development of the human residence and overuse of the natural resources bring about the destruction of nature and the natural ecosystem. Misbalancing the ecosystem in such a short time has misbalanced the sustainability of water resources and plant, animal and human ecology has been negatively affected, too. Considering all of these factors, the continuity of developing of the residences and the alteration of the land use will heavily damage the sustainability of the environment in Zayande Rood Basin. Also, with increasing the exploitation of aquifers, escalate the cycle of water resources instability, drought and ecological unsustainability.
    Keywords: Environmental consequences, Land Use Changes, ZayandehRud Basin, Underground Water, instability of water resources