فهرست مطالب

مدیریت جامع حوزه های آبخیز - سال دوم شماره 3 (پیاپی 5، پاییز 1401)

نشریه مدیریت جامع حوزه های آبخیز
سال دوم شماره 3 (پیاپی 5، پاییز 1401)

  • تاریخ انتشار: 1401/11/19
  • تعداد عناوین: 6
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  • حمزه سعیدیان* صفحات 1-30

    یکی از مهم ترین بلایای طبیعی، پدیده خشکسالی است و در صورتی که بیش از یک فصل یا یک دوره زمانی بلند، به طول انجامد دارای اثرات اقتصادی، اجتماعی و زیست محیطی است. خشکسالی را می توان معادل یک دوره یا شرایط آب و هوایی خشک و غیر عادی دانست که به اندازه کافی دوام داشته تا عدم تعادل جدی در وضعیت هیدرولوژیکی یک ناحیه ایجاد کند. در این تحقیق 19 شاخص خشکسالی مورد مطالعه قرار گرفته است. بررسی ها نشان داد که هر شاخصی با توجه به ماهیتی که دارد می تواند در مناطق مختلف مورد استفاده قرار گیرد و همه شاخص ها به نوبه خود و در مناطق سازگار با ماهیت این شاخص ها می توانند پایش مناسبی از خشکسالی داشته باشند. شاخص مناسب باید با توجه به منطقه مورد مطالعه، شاخص های منابع آب، شاخص های مربوط به گیاه و شاخص های مربوط به ریسک محصولات کشاورزی و اقتصادی و اجتماعی انتخاب شود. طبق بررسی منابع مورد مطالعه شاخص های دهک ها، بارش استاندارد شده، شدت خشکسالی پالمر، شاخص گیاهی اختلاف نرمال شده، شاخص بارش - تبخیر و تعرق استاندارد شده و شاخص بالم و مولی از پرکاربردترین و مناسب ترین شاخص های خشکسالی می باشند. همچنین ضعیف ترین شاخص خشکسالی مورد مطالعه، شاخص درصد نرمال بارش و قوی ترین شاخص های خشکسالی، شاخص های بارش - تبخیر و تعرق استاندارد و شاخص بالم و مولی می باشند. پیشنهاد می شود که با توجه به اینکه هر کدام از شاخص های خشکسالی در شرایط خاصی ایجاد شده اند یا در ایران مورد استفاده قرار نگیرند و یا اینکه با احتیاط مورد استفاده قرار گیرند. نتایج کلی تحقیق بیان می کند که بهتر است که در ارتباط با شاخص های خشکسالی با توجه به داده های هواشناسی و هیدرولوژیکی ایران، مدل سازی های آماری رگرسیونی خطی و غیر خطی بومی با توجه به اقلیم های خاص ایران صورت گیرد و شاخص چند متغیره خشکسالی ایرانی معرفی شود که قطعا نتایج ارزشمندتری به دنبال خواهد داشت.

    کلیدواژگان: خشکسالی، شاخص، اقلیم، وسعت خشکسالی
  • امیر مرادی نژاد*، مهدیه کریمی، راشین پورمتین، عباس صابری صفحات 31-43

    محدودیت آب به عنوان یکی از مهمترین موانع توسعه کشاورزی، در مناطق اقلیمی خشک و نیمه خشک محسوب می شود. استحصال آب باران یکی از مهمترین روش های مدیریت بهره برداری از آب باران برای مقابله با کم آبی می باشد. هدف این تحقیق، ترویج سامانه های سطوح آبگیر در استقرار و توسعه کشت گل محمدی در شرایط دیم است. در این تحقیق عرصه ای با شیب حدود 20% انتخاب شد و سطوح آبگیر باران در قالب سه تیمار و پنج تکرار در اراضی شیب دار روستای کتیران شازند اجرا شد. سامانه های سطوح آبگیر، شامل تیمار زمین تمیز شده  با استفاده از فیلتر در چاله نهال، تیمار سامانه نیمه عایق با استفاده از فیلتر در چاله نهال و شاهد طبق عرف محل اجرا شد. هر سال خصوصیات ارتفاع، تاج پوشش و زنده مانی نهال های گل محمدی در آخر فصل رشد اندازه گیری شد. نتایج تجزیه واریانس نشان داد که، اثر تیمارهای آبیاری بر روی صفت ارتفاع در سال های 1397 با سطح احتمال یک درصد (01/0<p) و در سال 1398 و  1399 اثر تیمار روی صفت ارتفاع  در سطح احتمال  (05/0<p)  معنی دار شد. بیشترین ارتفاع نهال مربوط به تیمار سامانه نیمه عایق با فیلتر و کمترین ارتفاع و تاج مربوط به تیمار شاهد می باشد. اثر تیمارها روی صفت طول تاج در تمام سال های 1397، 1398، 1399، 1400و 1401 معنی دار می باشد. در سال های 1400 و 1401 اثر تیمارها روی صفت ارتفاع معنی دار نبود. به طور کلی احداث سطح عایق برای جمع آوری آب باران در مناطق خشک و نیمه خشک ضروری است ولی برای کاهش هزینه احداث باید فناوری آن بهبود یابد. توصیه می شود طرح ها و برنامه های ترویجی و حفاظتی با اولویت زمین هایی که شیب بیشتری دارند، اجرا شود.

    کلیدواژگان: سطوح شیب دار، سطوح عایق، آبگیر باران، گل محمدی، دیم
  • نجمه حاج سید علی خانی*، حمزه سعیدیان، فریدون سلیمانی صفحات 44-57

    در مناطق خشک و کم باران به دلیل شرایط خاص جوی و اقلیمی که تبخیر بالا می باشد، امکان ذخیره سازی سطحی آبها در بسیاری از موارد، در مقیاس کوچک مشکل و غیر اقتصادی است؛ بنابراین مطالعات سدهای زیر زمینی اهمیت بسزایی دارد. برای انجام این تحقیق، حوزه آبخیز سد زیرزمینی راین در جنوب شهر راین در استان کرمان انتخاب شد. مطالعات ژیوالکتریک سد زیرزمینی منطقه راین در چند مرحله و در مجموع با 35 سونداژ الکتریک انجام گردید. نتایج تحقیق نشان داد که مقاومت ویژه الکتریکی سنگ کف از بالادست به سمت محور پیشنهادی افزایش می یابد. این مسیله بیانگر تغییر سنگ کف در محدوده نزدیک به محور پیشنهادی نسبت به نقاط بالادست می باشد اما مقادیر مقاومت ویژه الکتریکی مربوط به لایه آبرفتی در کل محدوده مورد مطالعه تغییر چندانی نشان نمی دهد و این حالت بیانگر وجود یکنواختی لایه آبرفتی در بازه مورد مطالعه می باشد. مقادیر مقاومت ویژه الکتریکی سنگ کف، در مجموع نسبت به مقادیر ویژه الکتریکی لایه آبرفتی بالاتر است و لایه آبرفتی به علت وجود املاح فراوان و آب لب شور در آن مقاومت ویژه الکتریکی پایینی را نشان می دهد. ضمنا دامنه مقاومت ویژه الکتریکی رسوبات و سنگ های مختلف در مجموع حداقل 36 اهم - متر و حداکثر 1313 اهم - متر را از خود نشان دادند و نوع روش ژیوالکتریکی به کار برده شده نیز به شیوه برداشت چهار الکترودی با آرایه شلومبرژه می باشد.

    کلیدواژگان: سنگ بستر، ژئوتکنیک، خشکسالی، راین
  • هما رزمخواه*، عماد قهرمانی، علیرضا فرارویی، امین رستمی راوری صفحات 58-81

    خشک سالی یکی از پدیده های آب و هوایی است که خسارت های زیادی به بار می آورد. با توجه به اینکه بخش قابل توجهی از آب سه رودخانه کارون، مارون و زهره از استان کهگیلویه و بویراحمد تامین می شود، بررسی خشک سالی در این استان ضروری می باشد. هدف از این پژوهش بررسی تطابق خشک سالی هواشناسی و هیدرولوژیکی حوضه است. بدین منظور تغییرات ماهانه دبی، بارش و تراز آب زیرزمینی در سطح حوضه بررسی گردید. خشک سالی هواشناسی توسط شاخص شاخص بارش استاندارد SPI برای 10 ایستگاه سینوپتیک و باران سنجی، در دوره 30 ساله، و شاخص SWI (شاخص سطح آب استاندارد) برای 11 چاه پیزومتریک برای کل دوره آماری موجود محاسبه شد. در پایان مقایسه بین خشک سالی هواشناسی و هیدرولوژیک انجام گرفت. نتایج نشان داد که هر زمان SPI منفی باشد، سطح آب زیرزمینی افت بیشتری نشان می دهد. این کاهش با تاخیر زمانی همراه بوده و با افزایش مقیاس زمانی خشک سالی، تاخیر بیشتر می شود. در سال های اخیر تداوم و شدت خشک سالی ها افزایش یافته است. بیشترین حجم کمبود (مقدار) بارش 3، 6، 9 و 12 ماهه ایستگاه نازمکان در سال 1388، بیشترین شدت 3، 6 و 9 ماهه در 1383 و 12 ماهه در 1388 به وقوع پیوسته است. با افزایش مقیاس زمانی خشک سالی ها، تداوم بیشتر و تکرار کمتر شده است. نتایج سایر ایستگاه ها تقریبا مشابه بود. تغییرات SWI چاه باشت نشان داد که خشک سالی های 6، 12، 24 و 48 ماهه حدود 48 ماه، از اسفند 1386 تا شهریور 90 تداوم داشته اند. شدت 48 ماهه بیشترین بود و بعدازآن به ترتیب 12، 24 و 6 ماهه قرار دارد. روند فوق نشانگر تاثیر دراز مدت و تجمعی خشک سالی هواشناسی بر روند نزولی آب زیرزمینی بوده، هرچند برداشت از آب ها نیز بی تاثیر نیست. روند SWI در سایر چاه ها تقریبا مشابه بود. مطابق آزمون kendall-Mann (من کندال) در بررسی روند دبی رودخانه و تراز آب چاه ها، روند دبی تایید نشد، ولی روند صعودی افت تراز چاه ها تایید شد. حداکثر همبستگی بارش-دبی در یک ماه مشاهده شد، که عمدتا ناشی از ارتباط مستقیم آب سطحی و زیرزمینی، و کمبود بارش برف است. بیش ترین همبستگی تراز آب زیرزمینی-بارش، و تراز آب زیرزمینی-دبی با دو ماه قبل مشاهده شد، که تاییدی بر تغذیه آب زیرزمینی توسط آب سطحی، و مدت زمان لازم برای نفوذ و حرکت آب در آبخوان است. نتایج موید نیاز به توجه و برنامه ریزی مناسب استفاده از منابع آب در استان است.

    کلیدواژگان: شاخص SPI، شاخص SWI، خشکسالی هواشناسی، خشکسالی هیدرولوژیک
  • رسول کرمی، مهدی امیرآبادی زاده*، محسن پوررضا بیلندی، مصطفی یعقوب زاده صفحات 82-94

    امروزه افزایش غلظت گازهای گلخانه ای در اتمسفر سبب تغییر در مولفه های منابع آب در مقیاس جهانی و منطقه ای شده است. از سوی دیگر پیش بینی آورد رودخانه در دوره آتی، ابزاری کارآمد در مدیریت منابع آب به حساب می آید. در این پژوهش عملکرد مدل های IHACRES و سیستم استنتاج عصبی - فازی (ANFIS) در پیش بینی رواناب حوضه سد کریت در طبس گلشن مورد بررسی قرار گرفت. داده ورودی به مدل های شبیه سازی بارش- رواناب IHACRES و مدل سیستم استنتاج عصبی فازی، شامل بارش و دما در مقیاس ماهانه است. پس از واسنجی دو مدل در بازتولید آورد رودخانه مشاهداتی، ارزیابی با استفاده از شاخص های RMSE و NS صورت پذیرفت. در این تحقیق، 60 درصد داده های بارش، دما و رواناب مشاهداتی برای آموزش و 40 درصد باقیمانده داده ها برای صحت سنجی مورد استفاده قرار گرفتند. معیار های ارزیابی RMSE و NS در بخش صحت سنجی در مدل IHACRES به ترتیب 1/0 و 95/0 و برای مدل ANFIS به ترتیب 05/0 و 52/0 محاسبه شد که نشان دهنده برتری مدل IHACRES نسبت به مدل سیستم استنتاج عصبی فازی در بازتولید دبی جریان مشاهداتی در این مرحله است. پس از مشخص شدن مدل برتر، با استفاده از مدل ریزمقیاس نمایی LARS- WG5.0 تحت سناریوی RCP4.5 و خروجی مدل گردش عمومی جو- اقیانوس GISS-E2-R، داده های بارش و دما برای سال های 2022 تا 2051 ریزمقیاس گردید و سپس با مدل برتر، مقادیر دبی برای سال های آینده نزدیک برآورد گردید. براساس نتایج حاصل از شبیه سازی جریان توسط مدل برتر (مدل IHACRES) در افق آینده مقادیر دبی جریان در رودخانه  در مقایسه با ماه های متناظر در دوره پایه، افزایش اندکی خواهد یافت.

    کلیدواژگان: تغییر اقلیم، طبس گلشن، مدل بارش-رواناب، عصبی-فازی
  • امیر مرادی نژاد*، سعید خسروبیگی صفحات 95-110

    با توجه به نقش کربن آلی در مدیریت و پایداری خاک، جلوگیری از فرسایش خاک و پایش میزان دی اکسیدکربن هوا، پیش بینی کربن آلی خاک در مقیاس منطقه ای، ملی و جهانی از اهمیت خاصی برخوردار است. در این تحقیق به منظور برآورد کربن آلی خاک از مدل های شبکه عصبی مصنوعی  و رگرسیون چند متغیره استفاده شد. برای این منظور در ابتدا،  60 نمونه خاک از حوزه آبخیز پاکل اراک از عمق 0 تا  30 سانتی متری برداشت شد. سپس خصوصیات خاک شامل نیتروژن، رس، سیلت، کربن آلی، اسیدیته، هدایت الکتریکی و وزن مخصوص ظاهری خاک اندازه گیری گردید. به منظور ارزیابی کارکرد مدل های مورد استفاده از مجذور میانگین مربعات خطا و ضریب کارآیی استفاده گردید. نتایج نشان داد که شبکه عصبی مصنوعی با مجذور میانگین مربعات 043/0=RMSE و ضریب کارایی 87/0=CE نسبت به مدل رگرسیونی با مجذور میانگین مربعات 08/0R=MSE و ضریب کارایی 51/0=CE  کارایی بهتری در برآورد کربن آلی داشت.  مقایسه بین مدل های رگرسیونی و شبکه عصبی نشان داد که مقادیر برآورد شده به وسیله شبکه عصبی دارای دقت بیشتری نسبت به روش رگرسیونی می باشد. روش های آماری و نتایج شبکه های عصبی برتری مدل های شبکه عصبی را در برآورد کربن آلی بیان می کند. نتایج کلی پژوهش نشان می دهد که در عرصه های طبیعی که مشکلات خاص نمونه برداری، هزینه های تجزیه و آنالیز نمونه ها در سطح زیاد وجود دارد، می توان از روش های هوش مصنوعی و به کمک داده های زودیافت برای تخمین کربن آلی خاک سود جست. انجام مطالعات دوره ای پایش ترسیب کربن در منطقه مورد مطالعه به منظور بررسی تغییرات زمانی ترسیب کربن در کاربری های موردنظر پیشنهاد می شود.

    کلیدواژگان: خصوصیات خاک، مدل سازی، ضریب کارآیی، کربن خاک
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  • Hamzeh Saeediyan * Pages 1-30
    Introduction

    One of the most important natural disasters is drought phenomenon. If it lasts longer than a season or a long period, it will have economic, social and environmental effects. Drought has no absolute definition and has a specific definition in each region. Each drought varies in severity, duration and extent. Moreover, Drought can be considered as the equivalent of a dry and unusual period or climate that lasts long enough to create a serious imbalance in the hydrological state of a region. Drought can also be regarded as an inevitable phenomenon, including disasters that cannot be prevented but can be managed and organized. Drought indices are an important tool for monitoring and evaluating drought and establish an accurate relationship between many climatic parameters. The information obtained from the indices can be useful for planners, designers and managers of water resources, which is also confirmed by comparative studies of indices.

    Materials and Methods

    This study focuses on studies of drought indices and how they function on different time and place scales. In order to conduct this research, the required materials were collected from domestic and foreign sources. In this study, 19 drought indices used in Iran and the world are evaluated, the results of different researchers are investigated, andlogical conclusions are made from different researches.

    Results and discussion

    The results showed that each index can be used in different regions according to its nature and water resources indicators, plant-related indicators and risk indicators of agricultural, economic and social indices. All indicators in turn and in areas compatible with the nature of these indicators can have a good prediction of drought, and these indicators all should not be compared because the results of this comparison will not be appropriate, but they should be selected appropriately according to the study area. Meanwhile, time scale is very important in each of the indicators and should be considered in order to achieve a more reliable result. Another point that was obtained from the results of this study is that most of the indices used in Iran and the world have paid more attention to the severity of drought andless to the duration, extent and frequency of drought, which is one of the weaknesses of existing drought indices in Iran and the world. An index of drought can persist in the world to pay for the severity, duration, frequency and extent of drought simultaneously and accordingly, it can definitely have appropriate predictions.

    Conclusion

    The results showed that the indices of DI, SPI, PDSI, SPEI, BMDI index are the most widely used drought indices. The results also showed that the weakest drought index is the PNPI index and the strongest indeices of drought are SPEI and BMDI indices. In general, in order to use drought indices, the time and place scale related to those indices should be considered in their use. Since each index of drought has been created under certain conditions,  it is suggested that they should not be used in Iran or be used with caution. The overall results of this study suggest that it is better to conduct native statistical models of linear and nonlinear regression according to specific climates of Iran in relation to drought indices according to Iranian meteorological and hydrological data and be introduced multivariate Iranian drought index which definitely has more valuable results.

    Keywords: Drought, index, Climate, Drought extent
  • Amir Moradinejad *, Mahdie Karimie, Rashin Pourmatin, Abass Saberie Pages 31-43
    Introduction

    Water limitation is regarded as one of the most important obstacles to agricultural development in arid and semi-arid climate regions. Rainwater harvesting is one of the most significant management methods of rainwater exploitation to deal with water shortage. Due to the wide variety of rainwater extraction methods, in choosing the appropriate method, special attention should be paid to features such as land topography, climate, soil type and socio-economic factors and the amount of water consumption to apply extraction methods in each region. In this research, the promotion of water catchment surface systems in the establishment and development of marigold cultivation in rainfed conditions has been discussed. The use of effective strategies to increase productivity in agriculture has been the focus of researchers for a long time. Any process that leads to the optimal use of rainwater and makes it possible to use it better is known as rainwater harvesting. The aim of this research is to promote the systems of water catchment surfaces in the establishment and development of rose cultivation in rainy conditions.

    Materials and methods

    The research area was chosen on the northern slope of the village with a slope of about 20%. Soil depth was measured by sampling. An 80 cm deep nationwide channel was dug downstream of the systems with an excavator. The channel was filled with a mixture of straw and stubble and a combination of animal manure with soil (in the amount of 20% by volume) in order to increase the moisture retention capacity in the soil. To carry out the present research, 12 rectangular catchment systems with dimensions of 6 x 5 meters were built using earth mounds on slopes with a 20% slope. These systems, due to being located on the slope and carrying out a series of measures in their beds, cause the production and direction of runoff towards the target point (seedling cultivation site). Downstream of each system, a hole was considered for planting seedlings. The research was carried out in the form of three system treatments including: cleaned ground using a pebble filter in the seedling hole, semi-insulated system treatment using a pebble filter in the seedling hole and a control (natural ground cover) according to local custom. To make a semi-insulated system, the vegetation on the surface of the system was first removed and the system bed was insulated using thick nylon and a 3 cm layer of gravel on it. Also, the downstream part of the system at the seedling pit was paved using the rubble in the area to reduce evaporation. Gravel filters are a column of gravel that is built in the upstream part of the seedling using two polyca pipes with a diameter of 10 cm and a depth of 40 to 50 cm during embankment at the foot of the seedling. Gravel was poured inside the pipes. In order to establish a hydraulic connection between the gravel column and the soil of the pit and its surroundings, the lower part of the pipe was meshed. These filters are used to optimally penetrate the extracted runoff to the depth of tree root development. To build the bare system, vegetation and pebbles were collected from the surface of the system.  

    Results and Discussion

    In variance analysis, the effect of irrigation treatments on the height trait in 2017 with a probability level of one percent (P<0.01) and in 2018 and 2019 the effect of treatment on the height trait at the probability level (P<0.05) was significant. The highest length of the height belongs to the third treatment (with filter and semi-insulating system) and the lowest height and crown belongs to the control treatment. Regarding the effect of the treatments on the crown length trait, it is significant in all years 2017, 2018, 2019, 2020 and 2021. In 2019, it is significant at the level of one percent (P < 0.01) and in the years 2017, 2018, 2014 and 2011 at the probability level (P < 0.05). In the years 1400 and 1401, the effect of the treatments on the height trait is not significant. The results show that the effect of the treatments on the crown is greater than that on the height. The highest crown was obtained in the third treatment (with filter and semi-insulated system) and the lowest crown was obtained in the control treatment. According to figure (5), in the years 2017, 2018 and 2019, the total rainfall in the spring season was 247, 285 and 187 mm, respectively, and in the years 1400 and 1401, it was 31 and 14.5 mm, respectively. Rainfall has a direct effect on the treatments. In fact, the amount of rainfall and its management in terms of systems of catchment surfaces, filters and insulation have a direct effect on the amount of moisture at the base of the plant, the water required by the plant, and the vitality of the rose.

    Conclusions

    The results showed that in the analysis of variance, the effect of irrigation treatments on the height trait in 2017 was significant with a probability level of one percent (P<0.01) and in 2018 and 2019, the effect of the treatment on the height trait was significant at the probability level (P<0.05). The highest length of the height belongs to the third treatment (with filter and semi-insulating system) and the lowest height and crown belongs to the control treatment. Regarding the effect of treatments on crown length in all years 2017, 2018, 2019, 2020 and 2021, it is significant. In 2019, it is significant at the level of one percent (P < 0.01) and in the years 2017, 2018, 2014 and 2011 at the probability level (P < 0.05). In the years 1400 and 1401, the effect of the treatments on the height trait is not significant. due to the the effect of spring rainfall on filter treatments and semi-insulated and filter systems.

    Keywords: Inclined surfaces, insulated surfaces, rain catchment, Damask Rose, Rainfed
  • Najmeh Haj Seyed Ali Khani *, Hamzeh Saeediyan, Fereydun Solaimani Pages 44-57
    Introduction

    In arid and low rainfall regions where evaporation is high due to special climatic conditions, the possibility of surface storage of waters in many cases, on a small scale, is difficult and uneconomic because part of the water is out of reach due to evaporation and the other part of the water is out of reach due to infiltration. Also, many surface reservoirs do not have a long shelf life and are filled and out of reach due to accumulation of sediments. Therefore, underground dam studies are very important. One of the new technologies used in the field of groundwater development is the underground dam, which is used for various purposes such as preventing the movement of saline waters in desert. Underground dams are compatible with environmental conditions.

    Materials and Methods

    To do this research, the watershed of The Rayen Underground Dam in the south of The City of Rayen and southeast of Karman city was selected. Geoelectric studies of the underground dam in The Reyen area were carried out in several stages with a total of 35 electric sondages. After harvesting the data and processing them by IPI2win software, the information of each of the harvest points in the region has been determined. The type of used geoelectric method is the harvesting method of four electrodes with Schlumberger array. 

    Results and discussion

    The importance of underground dams has been considered by most researchers around the world in recent years, and new types of methods are also used for their detailed studies, among which is the use of geoelectric method for studying underground dams. This has been considered in this research. Also, according to geological studies of Rayen region and geoelectric and topographic samples of the region, it can be concluded that the studied section is confined to two rock extrusions with the genus rhyolite and pyroclastic. Also, subsurface information of geoelectric sodages indicates the persistence of volcanic Igneous Stone below the intermediate surface between the two mentioned rock extrusions at a depth of 8 to 14 meters above the river bed surface and the slope of the bedrock from the sides to the center of the cross section in such a way that the maximum depth is in the center of the river and the minimum depth of bedrock is in the vicinity of rock extrusions. Considering the high importance of underground dams, it is suggested that the geoelectric studied methods in this study be studied more and more accurately to study underground dams in different watersheds throughout the country.

    Conclusion

    The results showed that the specific electrical resistance of the bedrock increases from upstream to the proposed axis. This indicates the change of bedrock in close range to the proposed axis compared to the upstream points. However, the specific resistance values related to alluvial layer in the whole study area do not change much and this state indicates the uniformity of alluvial layer in the study period. The specific resistance values of the bedrock are generally higher than the specific amounts of alluvial layer and the alluvial layer shows low specific resistance due to its abundant salts and brackish water. In addition, the specific resistance range of sediments and rocks showed a total of at least 36 ohms -meters and a maximum of 1313 ohms- meters.

    Keywords: Bedrock, Geotechnical, Drought, Rayen
  • Homa Razmkhah *, Emad Ghahremani, Alireza Fararouie, Amin Rostami Ravari Pages 58-81

    Introduction:

    Drought is a weather phenomenon that causes much damage every year. Kohgilouyeh and Boyer Ahmad province is located in the Southwest of Iran. Since it provides a substantial portion of the water of Karoun, Maroon, and Zohreh, which are three important rivers in this province, and evaluation and prediction of drought in this province seems necessary. This study aims to evaluate the compliance of meteorological and hydrological drought of the Zohreh river basin is in this province.

    Materials and methods

    Using SPI (Standardized Precipitation Index) and SWI index (Standardized Water level Indicator), the relationship between meteorological and hydrological drought was evaluated, and the comparison between the occurrence of meteorological and hydrological droughts was performed. The SPI was calculated for 10 meteorological stations with 30 years of data, and SWI for 11 piezometric wells for the whole statistical data available. The trend of the river streamflow and piezometric wells' groundwater levels was assessed using the Mann-Kendall test for 5 hydrometric stations and the piezometric wells. The Pearson correlation coefficient was used to assess the relationship between rainfall, discharge, and groundwater level in different time lags.

    Results and Discussion

    Results showed that in negative SPI durations, the groundwater level decreased with some delay. The delay increased when the drought scale increased. In recent years, the duration and intensity of drought have increased. Maximum volume of 3, 6, 9, and 12 months precipitation drought of Nazmakan station occurred in 1378-78, the maximum intensity of 3, 6, and 9 months in 1383, and 12 months occurred in 1388. When the drought scale increased, drought duration and intensity increased, and the drought frequency decreased. Results for the other stations were nearly similar. SWI of Basht well showed that 6, 12, 24, and 48 months droughts continued nearly 48 months, from the end of 2006 to the middle of 2010. The intensity of 48 months drought was maximum and 12, 24, and 6 months were in the next level of intensity. This trend shows the long time accumulating effect of meteorological trends on the decreasing level of groundwater, although pumping withdrawal of groundwater is also effective. The trend for other wells was nearly similar. The Mann-Kendall test did not confirm the trend of stations discharge, but the decreasing level of groundwater in all wells was statistically confirmed. The Pearson’s coefficient of precipitation-discharge showed the maximum correlation with the same month data. It could be from the surface water's direct relation with groundwater, and the decreasing amount of snow precipitation in recent years, which lead to a delay between them. The maximum Pearson’s correlation of the groundwater level -precipitation, and groundwater level -discharge was observed with two months delay. It could verify the groundwater recharge with surface water, and the time needed for infiltration and movement of water in the aquifer.

    Conclusions

    The results could be used for predicting the effects of meteorological drought on hydrological drought. The properties of meteorological and hydrological droughts could be used to manage drought and water resources, supply water for agriculture, industry, and livestock, and supply drinking water for humans in the province.

    Keywords: Meteorological drought, Hydrological drought, SPI index, SWI index
  • Rasool Karami, Mahdi Amirabadizadeh *, Mohsen Pourreza Bilondi, Mostafa Yaghoobzadeh Pages 82-94
    Introduction

    Today, the increase in the concentration of greenhouse gases in the atmosphere causes changes in the components of water resources on a global and regional scale. On the other hand, forecasting the river flow in the future period is considered a basic tool in water resources management. The rainfall-runoff process is completely non-linear, and it is completely random in terms of time and place. Therefore, it is not possible to easily describe its mechanism using simple models. The IHACRES hydrological model is used to simulate precipitation and runoff in large basins and most weather conditions, and it is also an integrated and conceptual model. The main advantage of this model compared to other rainfall-runoff simulation models is the acceptable accuracy of the results along with the use of minimal input data and its simple structure. The aim of this research is to compare the performance of IHACRES models and the fuzzy neural inference system in the simulation of the outflow of the catchment of Kurit Dam in Golshan Tabas and its forecast in the near future under the RCP4.5 scenario and the large-scale GISS-E2-R model.

    Material and method

    In this research, the performance of IHACRES models and Adaptive Neuro-Fuzzy Inference System (ANFIS) in forecasting the runoff was investigated. Model performance comparison of these models introduced the superior model. To simulate the future climate, the downscaling LARS-WG5.0 model was used under the RCP4.5 scenario. The temperature and precipitation data of the output of the large-scale model of the fifth GISS-E2-R report of the American country were extracted from the site. The precipitation and temperature data from 2022 to 2051 were downscaled and then the discharge values for the mentioned years were estimated with the superior model. The input data to the IHACRES rainfall-runoff simulation models and the ANFIS model include rainfall and temperature on a monthly scale. In this research, 60% of observed precipitation, temperature, and runoff data were used for training and the remaining 40% of data were used for validation of ANFIS and IHACRES models. After calibration of the two models, evaluation was done using RMSE and NS indices.

    Results and Discussion

    Investigation of linear correlation between precipitation and temperature with observed runoff showed that there is a significant relationship between precipitation and runoff in low and high monthly precipitation, but changes in observed runoff and temperature do not have a significant correlation (at the 95% confidence level). The evaluation criteria of RMSE and NS in the validation section of the IHACRES model were calculated as 0.1 and 0.95 respectively, and for the ANFIS model as 0.05 and 0.52 respectively, which shows the superiority of the IHACRES model over the fuzzy neural inference system model at this stage. In order to complete this section, as explained in the research method section, the LARS-WG5.0 software was used for downscaling of precipitation and temperature output of the large-scale model GISS-E2-R in the near future (2022-2051) under the RCP4.5 scenario.  Extracting the long-term monthly average showed that the average values of precipitation and temperature in the future horizon are equal to 17.38 mm and 21.7 °C, which, compared to the same values in the base period, shows that an increase of 5.45 mm in the average monthly precipitation and 2.9 °C an increase in the average temperature will occur. It can also be expected that this change in the values of climatic parameters will cause changes in the runoff caused by precipitation in the future. After simulating the monthly rainfall and temperature data from 2022 to 2051 by the LARS-WG5.0 downscaling model, these data were given as input to the IHACRES model to simulate the discharge by this model for the near future time period. Based on the results of flow simulation by the superior model (IHACRES model), the flow rate in the river will increase in the near future horizon.

    Conclusion

    In this research, In order to evaluate the IHACRES models and the adaptive neuro-fuzzy inference system, the available data (2013-2018) were divided based on the ratio of 60% to 40% for calibration (2013-2016) and validation (2016-2018). The validation result showed that the IHACRES model was more capable than the neural-fuzzy inference system model in simulating the observed runoff at Mavder station. The American GISS-E2-R large-scale model and the RCP4.5 scenario was used as input of hydrological model to simulate the runoff in the near future horizon. The results of statistical downscaling by LARS-WG from 2022 to 2051 showed an increase of 2.9 °C in temperature and an increase of 5.45 mm in total monthly precipitation. The output of the downscaling model was used as the input to the superior IHACRES model to simulate the runoff in the near future horizon for the investigated watershed.

    Keywords: Adaptive neuro-fuzzy inference system, Climate change, Golshan Tabas, Rainfall-runoff model
  • Amir Moradinejad *, Saied Khosrobeig Pages 95-110
    Introduction

    Organic carbon is one of the most important components of soil ecosystems, and changes in its amount and composition have fundamental effects on the processes that occur in each system. Soil is a source for carbon storage and deposition in connection with the atmosphere. Since pastures have a great capacity for carbon sequestration and are broad in arid and semi-arid areas of Iran, the study of organic carbon content and spatial changes in these ecosystems are important. In developing countries such as Iran, which are facing a soil erosion crisis, this issue can lead to the creation of a solution that aims at soil conservation, optimal utilization of land, as well as reforming and reviving destroyed pastures. Considering the role of organic carbon in soil management and stability, preventing soil erosion, monitoring the amount of carbon dioxide in the air, and predicting soil organic carbon on a regional, national and global scale are of particular importance.

    Materials and methods

    The study area of this project is the Pakel catchment from the sub-basins of the Qara Chai River. This catchment is located in the southwest of Shazand city, at a distance of 43 kilometers from the city of Arak. Random-systematic sampling was done in 60 points from the soil depth of 0-30 cm. Soil properties such as apparent specific gravity by cylinder method, pH and EC were measured after the preparation of saturated soil. Organic matter were measured using cold method based on oxidation of organic carbon. Then, soil properties were used to model soil organic carbon. For this purpose, statistical regression and artificial neural network were used.

    Discussion and results

    The amount of organic carbon in the soil is affected by the physical and chemical properties of the soil. It is therefore necessary to use calculation methods with optimal accuracy in estimating this complex and important parameter. It is possible to compare different models using RMSE, R2 and CE indices. Paying attention to the index values ​​shows the relative advantage of the models. The general results of the research show that in natural areas where the problem of sampling and the costs of their analysis are at a high level, it is possible to use artificial intelligence methods with the help of data to estimate soil organic carbon. It is expected that in future studies, in order to create a more reliable model that predicts more variability of the amount of soil organic carbon, denser sampling and integration of physiographic and soil variables affecting organic carbon will lead to satisfactory results. Due to the complexity of soil organic carbon relationships and soil physical and chemical properties, it is better to ignore complex analyses that include various coefficients for adjusting the mathematical formulas of models and use artificial intelligence methods which have high flexibility.

    Conclusion

    The results showed that the artificial neural network with RMSE=0.043 and CE=0.87 compared to the regression model with RMSE=0.08 and CE=0.51 is better in estimating organic carbon. The comparison between the regression and neural network models showed that the values ​​estimated by the neural network are more accurate than the regression method. It is suggested to carry out periodic carbon deposition monitoring studies in the study area in order to check the temporal changes of carbon deposition in the intended land uses.

    Keywords: soil characteristics, Modeling, efficiency coefficient, Soil carbon