@article { author = {Maleki, Mohsen and Rezaei, Ebaollah and Hosseini Nasab, Masumeh Sadat}, title = {The conflict between stakeholders in Ardabil and Germi counties, Ardabil Province, Iran}, journal = {Water and Soil Management and Modelling}, volume = {1}, number = {3}, pages = {1-14}, year = {2021}, publisher = {University of Mohaghegh Ardabili}, issn = {2783-2546}, eissn = {2783-2546}, doi = {10.22098/mmws.2021.9159.1025}, abstract = {Introduction What has been identified as the relationship between natural resources and conflict? In what ways are natural resources used to trigger conflict and instability? Who are the main players and actors in resource conflicts? To address these questions, this article critically reviews the main theoretical and empirical works on natural resources conflict. This area was studied as the target population due to the rich forest and rangelands resources and considering the existing conflicts in the Ardabil province. The conflict of interest between exploiters and natural resource experts is one of the problems that may have remained from the period of nationalization of forests and rangeland (1962) and has become more critical gradually. In this regard, the inapplicability of the laws, the numerous transfers that have taken place over the years, and the lack of transparency of the border between national lands and exceptions, have led to many problems. This study seeks to investigate the reasons and causes of the conflict between the key natural resources key stakeholders including beneficiaries people who use the rangelands or forest and the local authority or national actors (government) over natural resources in the study area.Materials and Methodslegal, managerial, exploitation, and social components were examined from the perspectives of both experts and stakeholders. A number of 205 questionnaires were completed by the officials of natural resources of Ardabil and Garmi cities and its stakeholders with the Snowball Method. The validity of the main variables was more than 0.7, which is an acceptable number. Divergent validity index, among all features, was less than 0.9, which indicated that there is no dependence between the variables of each feature. Since the scale of measuring the views of experts and stakeholders is the rating, the non-parametric Mann-Whitney U-test was used to compare the views of two groups on the causes of conflict in natural resources.Results and Discussion The results showed that the natural resources conflict in the whole region, there isn’t a significant difference between the factors affecting the conflict between the local community and government experts in terms of perspective. The most important components for increasing the conflict in this region from the perspective of beneficiaries are lack of expertise of the resolution council, lack of government support for ranches, financial poverty, conflict with rangeland encroachers, low level of awareness of stakeholders, and according to the experts, lack of government support for ranches, lack of law, lack of rangeland cooperative, insufficient water in rangeland, financial poverty, lack of cooperation among the people and migration. Land grabbing, coaling, wood smuggling, and understory tillage aren’t the most challenging issues. From the managerial point of view, both groups have declared that the most effective way to reduce the conflict is the confinement of forests and pastures, but the participatory management issues were not acceptable according to the two groups’ viewpoints. Effective presence of experts in the field, recognizing the livelihood potentials of the region and encouraging and educating people to know alternative jobs are suitable ways to reduce the conflicts.Conclusion It seems that the plans of stopping the exploitation of natural resources are more accepted in this region. Participatory management is one of the solutions to reduce the conflict which necessity of its implementation was not acceptable according to the two groups’ viewpoints.}, keywords = {Conflict,Exploitation,Governance,Natural resources,Social factors}, title_fa = {تعارض بین گروداران کلیدی منابع ‌طبیعی در شهرستان‌های اردبیل و گرمی (استان اردبیل)}, abstract_fa = {نقش مراتع و جنگل‌ها، در شیوة زندگی مردم وابسته به طبیعت، بسیار مهم و مؤثر است. با توجه به کمبود منابع و تنوع مصرف‌کنندگان، تعامل بین بهره‌برداران منابع ‌طبیعی و متولیان آن، در موارد زیادی به تعارض منجر می‌شود. شناخت عوامل مؤثر در تضاد بین گروداران کلیدی، از ارکان مدیریت منابع ‌طبیعی است. با توجه به منابع غنی جنگلی و مرتعی در استان اردبیل و تعارض‌های موجود، این منطقه به‌عنوان هدف، انتخاب شد. سپس مؤلفه‌های حقوقی، مدیریتی، بهره‌برداری و اجتماعی از منظر بهره‌برداران و کارشناسان بررسی و 205 پرسشنامه به‌روش گلوله‌برفی تکمیل شد. روایی متغیرهای اصلی پژوهش بیش‌تر از 7/0 به‌دست آمد. برای مقایسه دیدگاه دو گروه از آزمون ناپارامتری یومن-ویتنی استفاده شد. نتایج نشان داد که در کل منطقه تضاد منابع طبیعی وجود دارد، اما از نظر اختلاف دیدگاه، تفاوت بین بهره‌برداران و کارشناسان دولتی در خصوص عوامل مؤثر در تضاد معنی‌دار نیست. مهم‌ترین مؤلفه‌های مؤثر در افزایش تضاد در این منطقه از دیدگاه بهره‌برداران، تخصصی نبودن شورای حل اختلاف، کمبود حمایت دولت از دامدار، فقر مالی، نزاع با متجاوزین به حدود مراتع و سطح آگاهی مردم بود. از نظر کارشناسان، کمبود حمایت دولت از دامدار، نقص قوانین، عدم وجود تعاونی مرتع‌داری، ناکافی بودن آب در مراتع، کاهش همیاری در بین مردم و مهاجرت معرفی شد. زمین‌خواری، قاچاق چوب و شخم زیراشکوب، توسط هر دو گروه، به‌عنوان عامل مؤثر قوی در تضاد معرفی نشد. از نظر مدیریتی نیز مؤثرترین روش کاهش تضاد توسط هر دو گروه، قرق جنگل‌ها و مراتع بود، ولی لزوم مدیریت مشارکتی از نظر هر دو گروه، اولویت نداشت. در مجموع، حضور مؤثرتر کارشناسان منابع ‌طبیعی در عرصه، شناخت پتانسیل‌های معیشتی منطقه، تشویق و آموزش مردم به شناختن مشاغل جایگزین ‌راه‌کار مناسبی در کاهش تضاد است.}, keywords_fa = {بهره‌برداری,تعارض,حکمرانی,عوامل اجتماعی,منابع طبیعی}, url = {https://mmws.uma.ac.ir/article_1303.html}, eprint = {https://mmws.uma.ac.ir/article_1303_bd7b8fc376de4db684ffa1b089ca8aa1.pdf} } @article { author = {Ghorbani Vaghei, Hojjat and Bahrami, Hossein Ali}, title = {Application of porous clay capsule technique in optimizing water consumption of citrus orchard}, journal = {Water and Soil Management and Modelling}, volume = {1}, number = {3}, pages = {15-24}, year = {2021}, publisher = {University of Mohaghegh Ardabili}, issn = {2783-2546}, eissn = {2783-2546}, doi = {10.22098/mmws.2021.9140.1024}, abstract = {IntroductionWater is one of the main important environmental factors limiting plant culture, in arid and semiarid regions like Iran. Providing continuous soil moisture content in the range of field capacity and reducing water losses in near root zone can play a key role in the development of soil and water management programs. Subsurface irrigation system with porous clay capsules are able to release water in the soil at field capacity range. This method is one of the traditional methods to reduce water consumption and increase water use effficiency for providing water requirement of plants in small scale farms at the worlds. There are different types of porous pipes. Clay nozzles are a type of porous clay pipes that allow optimal use of irrigation water due to the moisture supply of field capacity at the roots of plants.Materials and MethodsIn this study, subsurface irrigation with porous clay capsule nuzzle was used to provide the water  requirement of two fruitful plant (Grapes and Oranges) and measure the volume of water consumption in comparison with drip irrigation method. Porous clay capsule is able to release water into soil about field capacity in low hydroustatic pressure. The soil water content in field capacity was measured by mini soil Tensiometer in 30 kPa soil suction. Soil moisture in field capacity content was 28% for clay soil texture in citrus orchard. In subsurface and surface irrigation methods, 4 porous clay capsules and 2 dripper (8 litr.h-1), were placed for each citrus plant respectively. The volume of water consumed after each irrigation in both methods was measured by a water meter counter with precision +/-1 liter. In citrus plants, to compare the effect of irrigation type the collar diameter and plant height were studied for three consecutive years, and were compared using t-test (P<0.05).Results and Discussion The volume of water used in subsurface irrigation method was less than the surface irrigation method. The results showed that the water supply using buried porous clay capsule irrigation method for citrus plant compared to surface drip irrigation method was associated 42% reduction in water consumption.. Comparison of collar diameter and plant height of citrus plants showed that there was no statistically significant difference (p<0.05) in two irrigation methods. Collar diameter and height growth of citrus trees in subsurface and surface irrigation methods in 2015 compared to 2012 was about 2.5 times.Conclusion According to the results of the present study, it can be concluded that the use of porous clay capsules will be one of the most effective traditional methods of optimization and management in water consumption of small scale orchards, especially at arid and semiarid region. An examination of the work done to date on clay nozzles shows that less attention has been paid to the economic aspects and competitiveness of these parts with other nozzles available in the market. It seems that the challenge of sedimentation of water-soluble materials inside the parts or attacking the roots on them has prevented the entry of large private sector investors into this completely economic and high-income environment.}, keywords = {Soil field capacity,Subsurface irrigation,Vegetative growth,Water consumption}, title_fa = {بهینه‌سازی مصرف آب در مرکبات با استفاده از تکنیک کپسول‌ رسی متخلخل}, abstract_fa = {تأمین پیوسته رطوبت خاک در محدودة ظرفیت زراعی و کاهش تلفات آب در خارج از محدود‌ة‌ رشد ریشه می‌تواند نقش کلیدی در توسعة برنامه‌های مدیریت آب و خاک داشته باشد. سامانة آبیاری زیرسطحی با کپسول رسی متخلخل قادر به تأمین پیوستة رطوبت خاک در محدودة ظرفیت زراعی است. در این پژوهش اثر دو روش آبیاری زیرسطحی با کپسول‌رسی متخلخل و روش آبیاری سطحی از نوع قطره‌ای برای تأمین رطوبت مورد نیاز بوته پرتقال تامسون ناول مورد ارزیابی قرار گرفت. در نهال پرتقال برای مقایسة تأثیر روش آبیاری، تنها پارامترهای قطر رویشی یقه و ارتفاع بوته به مدت سه سال متوالی مورد بررسی قرار گرفت. هم‌چنین در این پژوهش حجم آب مصرفی بعد از هر بار آبیاری در هر دو روش توسط کنتور آب با دقت 1± لیتر اندازه‌گیری شد. نتایج نشان داد که تأمین رطوبت برای گیاه پرتقال به‌روش کپسول رسی متخلخل نسبت به‌روش آبیاری قطره‌ای سطحی با 42 درصد کاهش مصرف آب همراه بوده است. حال آن‌که اختلاف آماری معنی‌داری بین قطر رویشی یقه و ارتفاع بوته در دو روش در هر سه سال مشاهده نشد. هم‌چنین نتایج مشاهدات میدانی حاکی از تأخیر مدت زمان آبیاری در روش آبیاری زیرسطحی در مرداد ماه از شش روز به نه­ روز در مقایسه با روش آبیاری سطحی داشت. به‌طور کلی، با علم به محدودیت منابع آبی در کشور استفاده از کپسول‌ رسی متخلخل یکی از مؤثرترین روش‌های بهینه‌سازی و مدیریت در مصرف آب اراضی باغی خواهد بود.}, keywords_fa = {آبیاری زیرسطحی,باغ مرکبات,رشد رویشی,ظرفیت زراعی خاک}, url = {https://mmws.uma.ac.ir/article_1301.html}, eprint = {https://mmws.uma.ac.ir/article_1301_5c0c41c5260a4b86394985413d0ec8e5.pdf} } @article { author = {Torabipoudeh, Hssan and Yonesi, Hojjat Allah and Yosefi, Hossein and Arshia, Azadeh and Yarahmadi, Yazdan}, title = {Detecting groundwater resources potential in Isfahan Lenjanat region using weights-of-evidence model}, journal = {Water and Soil Management and Modelling}, volume = {1}, number = {3}, pages = {25-37}, year = {2021}, publisher = {University of Mohaghegh Ardabili}, issn = {2783-2546}, eissn = {2783-2546}, doi = {10.22098/mmws.2021.9197.1026}, abstract = {Introduction Identifying groundwater potential is a key requirement in groundwater conservation and management and is especially useful for engineers and designers looking for suitable locations for the exploitation of these resources. GIS-based methods have increased the accuracy and speed of groundwater surveys. Many researchers have focused on the use of GIS-based methods, remote sensing and machine learning, and statistical methods. These methods identified latent patterns in groundwater and obtain a nonlinear relationship between affecting variables. In this regard, the final groundwater potential map is determined using 12 effective variables based on ArcGIS and Weight-Of-Evidence (WOE) model for Lenjanat area, Isfahan Province.Materials and MethodsLenjanat study area is located in the southwest of Isfahan Province. It has a variable climate that is always affected by the central semi-arid and semi-humid areas of Chaharmahal and Bakhtiari Province. WOE model is based on standard deviation and used to predict the occurrence of accidents when there is enough data available to assess the relative importance of the layers using the statistical average. The Receiver Operating Characteristic (ROC) curve related to the groundwater potential mapping in the Lenjanat study area was prepared using SPSS software. The Area Under Curve (AUC) indicates the accuracy degree of the final map. The extent area of each curve indicates the model’s prediction ability. The value below the graph would be equal to unity in the best case and ideal scenario. This index is a suitable criterion to evaluate the model accuracy.Results and Discussion The areas with low elevation and low slope due to the high level of infiltration and water movement in the soil had a higher potential of groundwater, which is consistent with the results of the previous researchers. These areas had a higher groundwater potential in the east and flat terrains than in other directions. From the land use point of view, arable lands and areas with dense vegetation had the highest groundwater potential. The shorter the distance from the waterway and the higher the drainage density leads to the greater the groundwater potential. Areas with Aridsols soil have higher groundwater potential compared to the Entisol and Inceptisols categories. Soft alluvial sediments have a higher potential than other sediments. It is expected that the areas with high groundwater potential will be more in the eastern part of the region due to the high concentration of factors affecting the creation of potential groundwater conditions. The final groundwater potential map also determined these areas as high groundwater potential regions.Conclusion The results showed a higher sensitivity to land use and slope variables, which play an important role in water penetration. More than 60% of Lenjanat has moderate to very high groundwater potential. Identifying areas with high groundwater potential is important in determining areas for implementing management programs. It is suggested to use the WOE model with more input variables and other models to prepare a high accuracy potential map should be evaluated in future studies. }, keywords = {Geographic information system,ROC,topographic wetness index,weight of evidence}, title_fa = {پتانسیل‌یابی منابع آب زیرزمینی منطقة لنجانات اصفهان با استفاده از مدل وزن شواهد}, abstract_fa = {تعیین پتانسیل منابع آب زیرزمینی به­ویژه در کشورهای در حال ‌توسعه از موارد مهم و ضروری در مدیریت منابع آب محسوب می­شود. در این پژوهش، نقشۀ پتانسیل آب زیرزمینی به‌منظور مدیریت و برنامه­ریزی منابع آب زیرزمینی با استفاده از مدل وزن شواهد­ و سامانة اطلاعات جغرافیایی (GIS) در منطقۀ لنجانات اصفهان انجام شده است. به­منظور واسنجی و اعتبارسنجی نتایج، موقعیت جغرافیایی 624 چاه در منطقه به دو گروه تقسیم شدند. در اجرای مدل وزن شواهد از متغیرهای مؤثر در پتانسیل آب زیرزمینی شامل ارتفاع، شیب، جهت شیب، انحنای زمین، زمین‌شناسی، کاربری اراضی، خاک‌شناسی، شاخص رطوبت توپوگرافی، فاصله از گسل، تراکم گسل، تراکم آبراهه و فاصله از آبراهه استفاده شد. هم‌چنین برای اعتبارسنجی نتایج مدل­ها از منحنی مشخصۀ عملکرد ((ROC استفاده شد. مساحت زیر منحنی ((AUC برای مدل وزن شواهد، مقدار 6/81 درصد را ارائه داد که نشان از اعتبار بسیار خوب این مدل به‌منظور تعیین پتانسیل آب زیرزمینی در لنجانات است. حساسیت‌سنجی مدل­ به متغیرها نشان داد که این مدل در این منطقه به دو متغیر کاربری اراضی و شیب حساس­تر است. بیش از 60 درصد منطقه دارای پتانسیل آب زیرزمینی متوسط تا خیلی زیاد است. تعیین مناطق با پتانسیل بالای آب زیرزمینی از لحاظ شناسایی مناطق برای اجرای برنامه­های مدیریتی، حائز اهمیت است. از آن­جا که مناطق با پتانسیل پایین، نشان‌دهندة عدم شرایط مناسب جهت تغذیه و ورودی آب به سفره­های زیرزمینی است؛ در نتیجة حفر چاه در این مناطق و استفاده و برداشت از این چاه‌ها، توازن بین ورودی و خروجی سفره­های زیرزمینی را از بین می­برد و نهایتاً خشک شدن قنوات را نیز می‌تواند به دنبال داشته باشد .پیشنهاد می­شود که از مدل وزن شواهد با تعداد متغیرهای ورودی بیش‌تر نیز استفاده شود و هم‌چنین میزان دقت مدل­های دیگر نیز در مطالعاتی هم‌چون مطالعة حاضر برای تهیۀ نقشۀ پتانسیل با دقت بالا بررسی شود.}, keywords_fa = {سامانه اطلاعات جغرافیایی,شاخص رطوبت توپوگرافی,منحنی ROC,وزن شواهد}, url = {https://mmws.uma.ac.ir/article_1304.html}, eprint = {https://mmws.uma.ac.ir/article_1304_08eaacd7f522cceb54a024dcf2630e71.pdf} } @article { author = {Khalili, Reza and Montaseri, Hossein and Motaghi, Hamed}, title = {Evaluation of water quality in the Chalus River using the statistical analysis and water quality index (WQI)}, journal = {Water and Soil Management and Modelling}, volume = {1}, number = {3}, pages = {38-52}, year = {2021}, publisher = {University of Mohaghegh Ardabili}, issn = {2783-2546}, eissn = {2783-2546}, doi = {10.22098/mmws.2021.9300.1031}, abstract = {Introduction River pollution is one of the serious risks to the environment, water systems, and human health. Regular monitoring and protection of river water quality is therefore vital to meet environment, and human needs. The increasing trend to fresh water highlights the management of river water resources as a crucial resource. Meanwhile, population growth, irregular urbanization, industrialization, overuse of chemicals materials in agriculture (such as fertilizers and pesticides), discharge of domestic sewage, and solid waste into watercourses, sand mining in riverbeds, water transfer diversion, has seriously challenged the rivers regimes and river ecosystems.Materials and MethodsThe effect of agricultural activities on water quality in the Chalus River was examined. Sampling was conducted and analyzed in surface water at three points from October 2019 to September 2020. Three surface water samples were collected from each station and water quality variables were analyzed. The following water quality parameters have been analysed in the current study; temperature, pH, conductivity, soluble solids, suspended solids, turbidity, salinity, reduction of oxidation potential, alkali, total hardness. Also, oxygen demand parameters of dissolved oxygen, oxygen saturation, biological oxygen requirement were examined. Meanwhile, the nutrient-related water quality parameters include N-NH4, N-NO2, N-Np3, total phosphate, total phosphorus are also evaluated. The heavy metals, inorganic pollution parameters, and suspended chlorophyll content of biological parameters were the other investigated parameters. Multiple statistical methods were used for the results of analyzing the parameter including principal component analysis (PCA), Pearson correlation Coefficient (PCC), and cluster analysis (CA). In addition, water quality index (WQI) was used for determining quality of surface water, hazard quotient (HQ), and hazard index (HI) for evaluating the public health risk for heavy metals.Results and Discussion The water quality of Chalous River has decreased from S1 station to downstream. The water quality index based on public health risk assessment showed that station S1 water could be used as drinking water and did not pose a potential risk to the health of adults and children. However, the water quality at Station S2, and especially Station S3, cannot be used for drinking puprpos, due to improper quality and may poses potential risks to the health of adults and children. The station S1 with an average of 15.62 categorized in the excellent water quality category. Meanwhile, the station S2 and S3 with an average of 25.5, and 49.8 assigned as good water quality status, respectively. The amount of As, Cd, Co, Ni, Pb was very small at the studied stations. The hazard coefficient (HQ) and hazard index (HI) values calculated to determine the risk of heavy metal effects on health were identified as non-carcinogenic. HI values of heavy metals calculated for adults and children were Mn> Cu> Al> Zn> Fe, respectively. The manganese and copper are more involved in non-carcinogenic health risks. Also, the values of HQingestion and HQdermal values and the HI value are less than one.Conclusion A combination of point and non-point source pollution have been identified as the main source of water quality deterioration. The water quality parameters of Chalous River in S1 station has not exceeded the permissible level of the national standard of Iran. While, the water quality in S2, and S3 stations has decreased that poses potential risks to the human health and need a pollution prevention action plan. The factors such as municipal wastewater, septic tank and water leakage from horse stables, natural and artificial fertilizers used in agriculture, runoff and rock pebbles in the basin are the causes of pollution.}, keywords = {River flow quality,Chalus river,statistical analysis,water quality index}, title_fa = {ارزیابی کیفیت آب رودخانۀ چالوس با استفاده از تجزیه ‌و تحلیل آماری و شاخص کیفیت آب (WQI)}, abstract_fa = {آلودگی رودخانه‌ها یکی از خطرات جدی برای محیط‌ زیست، سیستم‌های آبی و سلامت انسان است. در این مطالعه اثر فعالیت‌های انسانی بر کیفیت آب در رودخانۀ چالوس مورد ارزیابی قرار گرفت. بدین‌منظور، نمونه‌برداری در دو دوره (مهر 1398 تا شهریور 1399) انجام شد. در هر دوره از هر ایستگاه سه نمونه از آب‌های سطحی جمع‌آوری و مورد تجزیه‌ و تحلیل قرار گرفت. در این پژوهش پارامترهای کیفیت آب (دما، pH، هدایت الکتریکی، مواد جامد محلول، جامدات معلق، کدورت، شوری، کاهش پتانسیل اکسیداسیون، قلیایی، سختی کل)، اکسیژن‌رسانی (اکسیژن محلول، اشباع اکسیژن، نیاز اکسیژن بیولوژیکی)، مواد مغذی ( ، ، ، کل فسفات، کل فسفر)، عناصر کمیاب، آلودگی غیرآلی و محتوای کلروفیل معلق از جمله پارامترهای بیولوژیکی بررسی شدند. روش‌های آماری متعددی برای نتایج تجزیه‌ و تحلیل پارامترها از جمله روش آماری مؤلفه‌های اصلی (PCA)، شاخص همبستگی پیرسون (PCI) و تجزیه‌ و تحلیل خوشه‌ای (CA) مورد استفاده قرار گرفت و هم‌چنین از شاخص کیفیت آب (WQI) برای تعیین کیفیت جریان آب و ضریب خطر (HQ) و شاخص خطر (HI) جهت بررسی ارزیابی ریسک از نظر بهداشت عمومی برای عناصر کمیاب استفاده شد. نتایج نشان داد که کیفیت آب رودخانة چالوس از ایستگاه S1 به‌سمت پایین‌دست به‌دلیل افزایش فعالیت‌های انسانی، جاده‌سازی در حاشیۀ بستر رودخانه، ورود پساب از زمین­های کشاورزی و فاضلاب خانگی و تخلیه فاضلاب مزارع پرورش دام در رودخانه کاهش ‌یافته است و هم‌چنین بررسی کیفیت آب رودخانه از نظر خطرات بهداشت عمومی نشان ‌داد که می­توان از آب ایستگاه S1 به‌عنوان آب آشامیدنی استفاده کرد و خطری بالقوه برای سلامت بزرگسالان و کودکان ندارد، اما از آب ایستگاه S2 و به‌ویژه ایستگاه S3 نمی‌توان برای آشامیدن استفاده کرد و باعث ایجاد خطرات بالقوه برای سلامت بزرگسالان و کودکان می‌شود.}, keywords_fa = {تجزیه‌ و تحلیل آماری,رودخانة چالوس,شاخص کیفیت آب,کیفیت آب رودخانه}, url = {https://mmws.uma.ac.ir/article_1324.html}, eprint = {https://mmws.uma.ac.ir/article_1324_d247dcdae7547d862b9d064060273615.pdf} } @article { author = {Ghafari, Heidar and Gorji, Manouchehr}, title = {Evaluation of soil erosion effects on rainfed wheat (Triticum aestivum) yield using SWAT model}, journal = {Water and Soil Management and Modelling}, volume = {1}, number = {3}, pages = {53-66}, year = {2021}, publisher = {University of Mohaghegh Ardabili}, issn = {2783-2546}, eissn = {2783-2546}, doi = {10.22098/mmws.2021.9267.1029}, abstract = {Introduction Although soil erosion in natural ecosystems takes place very slowly, yet its cumulative effects on soil productivity are significant in the long term, and even very low rates of erosion cause loss of considerable amounts of soil during the course of many years. Based on statistics presented during the past 40 years, about 30% of agricultural lands in the world have lost their fertility due to erosion and have turned into non-arable lands (Pimentel and Burgess, 2013), and approximately 75 million tons of fertile agricultural soil is lost every year (Eswaran et al., 2001). In another report, it has been stated that about 10 million hectares of agricultural lands in the world lose their productive capacity annually and become non-cultivable lands (Lal, 2001).Materials and MethodsSWAT model was used to simulate the effect of soil erosion on dry wheat yield. For this purpose, after model calibration and validation, the following five scenarios were defined to quantify the effects of erosion on rainfed wheat yield: (1) current soil depth, (2) removing 5 cm, (3) removing 10 cm, (4) removing 15 cm, (5) and removing 20 cm of current topsoil depth in soil database.Accordingly, a regression relation was established between surface soil erosion and wheat yield.Results and Discussion Regression analysis showed that for each centimeter of soil erosion, the yield of rainfed wheat was reduced by 15.1 kg equal to 0.5%. The model results showed that the average specific erosion in the agricultural lands of the region is about 10 t/ha (0.77 mm/year). Assuming that the erosion rate is constant over 100 years, about 77 mm of soil is destroyed, equivalent to a loss of 116 kg/ha of dryland wheat yield. Considering the area under wheat cultivation (about 50,000 ha) in the study region, it is estimated that 580 tons of wheat per year will be destroyed by erosion.Conclusion SWAT model was used to assess the effect of erosion on crop yield. The gradual decrease in horizon A depth of input soil data to the model showed that with a decrease in the soil depth per 10 cm, the average yield decreased by 5%. It is suggested that in subsequent studies, the results of this method can be compared and validated with the comparative plot method, as the best field method in evaluating the effect of erosion on yield.}, keywords = {Horizon A,Permissible Erosion,Soil Conservation,Soil Productivity}, title_fa = {ارزیابی اثر فرسایش خاک بر عملکرد گندم دیم با استفاده از مدل SWAT}, abstract_fa = {خاک مهم‌ترین منبع طبیعی به‌ویژه در زیست‌بوم‌های کشاورزی است که بستر رشد گیاهان را فراهم می‌کند. فرسایش خاک از طریق کاهش عمق خاک، آب قابل دسترس گیاه و هدررفت مواد معدنی و آلی باعث افت باروری خاک و در نتیجه تقلیل عملکرد گیاه می‌شود. آگاهی از روابط بین فرسایش و عملکرد محصول برای تعیین فرسایش قابل تحمل و برنامه‌های حفاظت خاک ضروری است. محسوس نبودن اثر فرسایش بر رشد گیاه در کوتاه مدت یکی از چالش‌های اصلی در تعیین رابطۀ بین فرسایش و عملکرد محصول است. بنابراین، پایش مستقیم اثرات فرسایش بر عملکرد محصول تقریباً غیرممکن است. به همین دلیل روش‌های غیرمستقیم برای این منظور پیشنهاد شده است. مدل‌سازی یکی از روش‌های سریع و ارزان برای ارزیابی اثر فرسایش بر تولید محصول است. در این پژوهش از مدل ارزیابی آب و خاک (SWAT) برای شبیه‌سازی اثر فرسایش بر عملکرد گندم دیم استفاده شد. برای این کار پس از واسنجی و اعتبارسنجی مدل، سناریوهای مختلفی در خصوص عمق خاک تعریف شد و با کاهش تدریجی ضخامت افق A در پرونده مربوط به داده‌های خاک میانگین عملکرد گندم دیم شبیه‌سازی شد. بر این اساس ارتباط بین میزان فرسایش خاک سطحی و عملکرد گندم برقرار شد. رابطۀ رگرسیونی نشان داد که به ازای هر سانتی‌متر فرسایش خاک، عملکرد گندم دیم به مقدار 15 کیلوگرم در هکتار معادل 5/0 درصد کاهش یافت. نتایج مدل نشان داد که میانگین فرسایش ویژه در اراضی کشاورزی منطقه حدود 10 تن در هکتار در سال (معادل 77/0 میلی‌متر در سال) است. با فرض ثابت بودن میزان فرسایش در طول 100 سال، حدود 77 میلی‌متر خاک از بین می‌رود، که معادل هدررفت 116 کیلوگرم در هکتار یا 8/3 درصد  از عملکرد گندم دیم است. با در نظر گرفتن سطح زیر کشت گندم (حدود 50000 هکتار) در حوضۀ مورد مطالعه، برآورد می‌شود که سالانه 580 تن گندم در اثر فرسایش از بین می‌رود. استفاده از این روش در مناطق مختلف و برای سایر محصولات و هم‌چنین اعتبارسنجی نتایج با آزمایش‌های مزرعه‌ای پیشنهاد می‌شود.}, keywords_fa = {آب قابل دسترس گیاه,افق A,باروری خاک,حفاظت خاک}, url = {https://mmws.uma.ac.ir/article_1288.html}, eprint = {https://mmws.uma.ac.ir/article_1288_5175cdde1de752bc89c4f09f0dbf3fe1.pdf} } @article { author = {Mirzania, Ehsan and Malek Ahmadi, Hossein and Shahmohammadi, Yadgar and Ebrahim Zadeh, Ali}, title = {Impact of wavelet on accuracy of estimated models in rainfall-runoff modeling (Case study: Sufi Chay)}, journal = {Water and Soil Management and Modelling}, volume = {1}, number = {3}, pages = {67-79}, year = {2021}, publisher = {University of Mohaghegh Ardabili}, issn = {2783-2546}, eissn = {2783-2546}, doi = {10.22098/mmws.2021.9335.1035}, abstract = {Introduction In recent decades, accurate modeling of runoff has always been one of the hottest topics for researchers in the field of hydrology, as it plays an important role in water resources management, hydropower development, urban planning, irrigation and other hydrological/meteorological activity programs. Concept-based and physical models require huge amounts of data and environmental calculations. The nonlinear nature of the rainfall-runoff process and the complexity of physical models are some of the reasons why researchers have turned to intelligent models. However, these models may not provide logical results for nonlinear hydrological processes. To overcome this shortcoming, nonlinear artificial neural networks (ANNs) have depicted a real success in predicting hydrological time series.Materials and MethodsThe usefulness of wavelet transforms in noise reduction and multi-resolution analysis along with the ability of ANNs to optimize and predict hydrological processes has recently been introduced as a neural network wavelet hybrid model (WANN) and is widely used by hydrologists not only for rainfall-runoff modeling. It has been used to simulate some other components of the hydrological cycle such as river flow, groundwater, precipitation and sediment. In this study, precipitation and discharge data on a monthly scale have been used. For modeling in this research, ANN and WANN have been used. Data were used for Sufi Chay Basin for period 2001-2019.Results and Discussion In this study, for modeling rainfall-runoff by neural network in MATLAB 2018 Software and investigating the effect of using wavelet transform on the accuracy of rainfall-runoff model has been done. First, the existence of autocorrelation and its significance in runoff data were investigated using the partial autocorrelation function (PACF). In the hybrid model, Daubechies mother wavelets 3 and 4 are used. Six scenarios were examined for modeling. Among the selected scenarios, scenarios 4 and 5 had the best results in comparison between the two models. The poor accuracy of the first three scenarios (Scenarios 1-3) indicates that using rainfall data alone are not sufficient to model runoff, thus employing the last monthly runoff data into the model made a significant change in the results. In the ANN model, scenario 4 has more acceptable results with correlation coefficient (r), square root mean square error (RMSE) and Nash Sutcliffe coefficient (NSE) of 0.889, 51.574 and 0.788, respectively for the training section, and 0.779, 70.625, and 0.595, respectively for the test section. In the hybrid model WANN, scenario 5 has the best results with the values of r, RMSE and NSE of 0.997, 23.99 and 0.954, respectively for the training section, and 0.829, 62.334 and 0.684, respectively for the test section.Conclusion In the present study, the performance of ANN and WANN models for rainfall-runoff modeling in Sufi Chay Basin using different parameters of rainfall and discharge delays during the statistical period (2001-2019) was evaluated. The highest accuracy of the models was provided in combining runoff input with a time delay and monthly precipitation. The purpose of this study is the effect of wavelet on increasing the accuracy of estimation in rainfall-runoff modeling. The results of the present study showed that the hybrid model will increase the accuracy of a model.}, keywords = {Rainfall – Runoff,ANN,WANN,Sufi Chay}, title_fa = {تأثیر موجک بر افزایش دقت مدل‌های تخمینی در مدل‌سازی بارش-رواناب (مطالعۀ موردی: حوضۀ صوفی‌چای)}, abstract_fa = {فرآیند بارش-رواناب از مهم‌ترین و پیچیده‌ترین پدیده‌ها در چرخه هیدرولوژی بوده و در مدل‌سازی آن، دیدگاه‌های متفاوتی برای توسعه و بهبود مدل‌های پیش‌بینی‌کننده ارائه شده است. لذا، بر حسب استفاده از روش‌های گوناگون، انواع مدل‌ها توسعه یافته‌اند. در این تحقیق فرآیند بارش-رواناب در حوضه صوفی‌چای با استفاده از شبکه عصبی مصنوعی (ANN) و هیبرید موجک-شبکۀ عصبی (WANN) مورد مطالعه قرارگرفته است. داده‌های بارش-رواناب در طول دورة آماری (98-1380) برای آموزش و صحت‌سنجی مدل‌ها مورد استفاده قرار گرفت و شش سناریو برای هر مدل در نظر گرفته شد. نتایج این سناریو‌ها نشان داد که بهترین ورودی‌ها برای مدل‌ها، مربوط به سناریوی پنج است که در آن از دبی با یک تأخیر، بارش ماه مورد نظر و بارش با یک تأخیر استفاده شده است. در حالت کلی نتایج حاکی از دقت قابل قبول هر دو مدل است. از لحاظ اولویت نیز مدل WANN با بیش‌ترین دقت ضریب همبستگی (r)، جذر میانگین مربع خطاها (RMSE) و ضریب نش-ساتکلیف (NSE) به‌ترتیب برابر 0.97، 23.99 و 0.95 برای مرحله آموزش و 0.82، 62.33 و 0.68 برای مرحله آزمون کمترین خطا در اولویت اول و مدل ANN در اولویت بعدی با مقادیر ضریب همبستگی (R)، جذر میانگین مربع خطاها (RMSE) و ضریب نش-ساتکلیف (NSE) به‌ترتیب برابر 0.93، 40.41 و 0.87 برای بخش آموزش و 0.81، 73.40 و 0.56 برای بخش آزمون قرار گرفتند و نتایج گویای این بود که موجک باعث بهبود نتایج و پیش‌بینی در مدل‌سازی بارش-رواناب شده است.}, keywords_fa = {بارش - رواناب,شبکه عصبی مصنوعی,هیبرید موجک-شبکه عصبی,صوفی چای}, url = {https://mmws.uma.ac.ir/article_1325.html}, eprint = {https://mmws.uma.ac.ir/article_1325_8469205a33eb11a3559556eb6e5610f9.pdf} }