Inundation in urban areas due to dens storm has created many problems for all cities thorough the world. Urban flood hazard zoning may provide useful information for dealing with contingency and alleviating risk and loss of life and property. Therefore, to management of urban area, flood relief measures and prioritized to address flooding problems should be identified areas that are more affected. Vulnerability of urban areas often includes multiple factors that are associated with flooding. One of the methods that are sufficiently accurate and use available data can identify flood hazard zoning, is using Evidential Belief Function (EBF) that in this study was used to determine the potential of inundation risk in urban area. Four variables include: distance to the main channel, slopes, drainage density and elevation was used. The potential of inundation risk in urban area final map of in the study area was prepared by method from the Evidential Belief Function of the four classes include: potential of inundation risk low, medium, high and very high classified. The prediction accuracy of the potential of inundation risk map obtained in Evidential Belief Function model in this region using Receiver Operating Characteristic (ROC) was evaluated and area rate under the curve 81.27 were obtained. The results indicate that the EBF model for zonation of potential of inundation risk in the study area is acceptable accuracy.

In recent years, rivers flows have significantly decreased due to regional or global climate change and human activities especially in the arid and semi-arid regions. In this study, the effect of climate change and human activities on the runoff responses was examined using hydrologic model simulation in the Lighvan basin located in the northwest of Iran. For determination of hydrologic model MLR methods (Forward and Ridge) were used. The Mann–Kendall test was applied to identify the trends in hydro-climatic data series. Also, the Pettitt’s test was adapted to detect change-points in the annual discharge values and climatic variables. The results showed that there was negative trend in discharge data series, so that in Hervy station it significant at 10%. Examination of the climatic factors indicated that there was an increase in the temperature values and a decrease in the relative humidity values at the basin. Also all variables related to precipitation in spring have decrease trends. The rapid changes in runoff values and most of the climatic variables occurred in mid-1990s. Comparison of the average discharge in the Hervy Station in the two periods indicates 36% decrease in the recent period compared to the natural period. The effect percentages of the human factors and climatic factors on runoff reduction in all the models used were 65%-84% and 16%-35%, respectively. Therefore, the impact of human activities on the river flow changes was significant.

In the present research, the climate change effect on variation of surface runoff of Zarrinehrud located in the Miandoab plain was investigated. In this direction, the scenarios including A1B, A2 and B1 via LARS-WG downscaling model and with applying the HadCM3 general circulation model and artificial neural network model in two different periods (2046-2065, 2080 -2099) were studied. For this purpose, the best combination of input parameters of the MLP artificial neural network model was selected to estimate the runoff among various meteorological parameters with time delay of zero and one day and runoff parameter with one-day delay. Then, the meteorological data predicted by the LARS-WG in the future were used as inputs for the selected neural network model and consequently the runoff was predicted. The comparison of results between observed and simulated data by LARS-WG model using different statistical and error measurement indices indicates that there is no significant difference between simulated and observed values. Performance analysis of the artificial neural network model indicates that the mentioned model has good and suitable accuracy to simulate the runoff variations in the studied area. The results showed that the average annual runoff in the period of 2046-2065 will increase about 4.62 CMS than base period and it will decrease about 14.7 CMS during the period 2080-2099 compared to the base period.

Nowadays, there are too many models in the world for simulation of hydrological processes, such as the SWAT physically based model. The SWAT model is a continuous and physically based hydrologic model that is the smallest unit in this model is Hydrologic Response Unit, and all hydrological processes are simulated in each of these units. This model can simulate runoff, sedimentation, erosion and chemical transfer in complex basins, taking into account different information layers such as soil, land use and digital elevation model of the basin. The first step in using these models is to prove their ability to simulate the water cycle of the basin. The SWAT model in Barandozchay basin simulated the monthly time step flow and the parameters involved in the hydrological processes calibrated. The SUFI-2 algorithm used in order to the calibration of the model. The time period of 2000-2011 and 2012-2016 were used for calibration and validation, respectively. The results of the calibration of monthly discharge with P-factor, R-factor, and NS criteria were 0.71, 0.32, and 0.66 and in validation process were 0.63, 0.36, and 0.51 respectively in Ghasemlou station. The results revealed that the high ability of the model in river flow simulation. Due to the weakness of empirical models in estimating watershed processes, it is recommended to use the physically based models in simulation of these processes.

Iranchr('39')s location on the arid world belt, the occurrence of climate change and global warming and the increased in human interference have resulted in dust storms phenomenon in the western and southwestern parts of the country, especially in Khuzestan province. The present study has been aimed at investigating the existing water resources of the province for the watering operation of the southeastern dust source of Ahvaz with the first priority for providing A quick solution. Since this site is located within the catchment area of the river of Koopal, to study the discharge rate and its runoff the station of koopal number 3 was selected and its average discharge and rainfall were surveyed during the years 1982 - 12014 and 1982 – 2012 respectively and the soil conservative service method of USA along with GIS and RS tehniques were used.The results showed that the average annual discharge rate of the Koopal River was, 2.49 m 3/s, so that the highest was in winter and the lowest was in summer. On the other hand, the results showed that the studied area from the southeast of Ahwaz can produce an annual runoff volume of 34.14 million cubic meters Which is 31 million cubic meters in fall and winter seasons. Therefore, regarding the annual runoff volume of koopal River and the southeast dust source of Ahwaz, especially in the winter season because of the increasing in the frequency of south-eastern wind as the main cause of dust storms phenomenon, to carry out the operations of watering and restoring vegetation cover with a proper management water usage plan in the upstream of the river.

One of the problems of some cities in the country, especially those in the vicinity of mountainous watersheds, is the containment and control of runoff, erosion and sedimentation that results in many damages to downstream facilities and infrastructure each year. Watershed operations have been proposed for years to reduce and mitigate destructive effects, and some measures have been taken in these areas. But evaluating such projects can play an important role in determining the effectiveness and future planning of natural resource management and execution plans. In this regard, in order to show the impact of this operation, two urban watersheds of District 5 (Koohsar) and District 22 of Tehran, which consist of a number of sub-basins, were selected, in which only biological operations (vegetation cover) and integrated operations (biological and structural), respectively implemented. Then, using the MPSIAC empirical model, the impact of operations performed in these basins was quantitatively calculated to reduce the internal factors of the model and its final output, erosion and sediment yield, in the two periods before and after the project implementation. The results show that in the first watersheds, biological operations including planting and vegetation development have a 45% impact on improving the natural environment of their urban watershed with reduced degradation, and in the second watersheds, a combination of structural and biological operations reduces the rate of erosion and sediment production by 55%. The results show the positive role of watershed management practices and the effectiveness of integrated methods in reducing the problems caused by upstream catchments overlooking cities and also shows how to deal with watershed activities in cities upper watersheds, is slightly different from the classical watershed management methods and should be considered with a different approach.

Sophisticated social- ecology systems, such as those in water management in a basin, are usually dynamic, multidimensional, or multidimensional, requiring serious engagement by multiple actors, and decision making in such systems is always faced with serious problems Kashafrood basin in Khorasan Razavi province is one of the most critical aquifers in the country due to the high population growth, high economic development, water scarcity and non-integrated allocation of water resources. In this regard, the best way to manage water is to create constructive interaction between actors involved in the basin. To this end, the present study has been conducted with a collaborative approach to provide a framework for identifying, analyzing and participating key actors in the decision-making process of this catchment area. This collaborative framework has two parts. The first part is the analysis of over 60 activists using the snowball method and the power-interest matrix, and the second part involves the involvement of key actors using the Circle of Influence Models (CI) and IAP2. The results of this study have led to the development of a common perspective on horizon 1420, in which the basin will have a sustainable balance in resources and water consumption. Under this vision, 19 strategies, 63 macro policies and 232 micro policy (executive), 41% of these policies have a social nature. The evaluation of the policy questionnaire, the implementation and effectiveness of the policies has shown that the majority of key actors in the basin have agreed on a high consensus on the implementation and effectiveness of those policies to achieve a common vision. According to the results of this research, the coherent framework presented can serve as a basis for identification, prioritization, analysis and collaboration of actors in order to increase their level of collaboration in the process of water management decision making in the basin of the country.

Statistical modeling methods are based on multivariate regression methods and require the presence and absence location of data for the construction of the model. In most cases, there is no trustworthy absence data. Therefore, other methods that are based only on the presence of the phenomenon are used. Considering the importance of modeling - saving time and cost and the probable prediction of the process - in this paper three sampling methods, Bootstrap, cross-validation (CV) and subsampling, were investigated to estimate areas with groundwater recharge potential using the maximum entropy model in the Marboreh watershed. The information about percolation points in Marboreh watershed, which was gathered using the double ring method and soil sampling, included the location of the samples, soil texture, and percolation rate. Due to the extent of the catchment area and the cost of the sampling process, information from previous studies in the study area, which were gathered from the Regional Water Authority (RWALP) and Agricultural Research, Education and Promotion Organization of Lorestan province (AREPOLP), was also used. The ROC index was used validate model predictions. The validation index indicated that the bootstrap had the best performance (ROC=0.955%). The results showed that each factors in these three methods was somewhat different, which was more than other factors in the drainage density, land use and soil texture. Based on the results of performance index, there is a very slight difference between the three sampling methods, so that they can be differentiated in relation to their different strategies, and this difference in the outputs, is not related to the diversity of the phenomenon studied. In this paper, according to the results and assessments, the Bootstrap method is recommended for the modeling the groundwater recharge areas due to the small number of sampling data compared to the very large area of study. Due to the large extent of the study area, it is suggested that this simulation be performed for more precision at smaller extent large areas with further data to study similar studies. Despite the increase in the number of pixels of high infiltration areas in the Bootstrap sampling method, compared to the other two methods, the performance of the recharge zoning increased slightly.

This study aims to simulate runoff and runoff quality of Zarrineh river basin by SWAT model. Calibration and verification were done respectively with monthly runoff statistics in SWAT CUP by SUFI2 method for 1992-2013, for 12 sub basin, 226 HRU and monthly nitrate data for 2006-2009. The highest runoff sensitivity and runoff quality with minimum Pvalue and maximum absolute value Ttest belong to soil cure number and nitrogen hydrolysis. The maximum number in calibration and verification belonged to Zarrineh dam station by R2=NS=0.81 and minimum number belonged to Janagha station by R2=NS=0.47. The value of these two coefficients in calibration of nitrate in all basin were 0.58 and 0.44 and their coefficient in verification were 0.51 and 0.42 respectively. Statistical results showed that a good performance in the SWAT model simulation of monthly flow and nitrate in the basin of Zarrineh river. Then the simulation was conducted by best management practices model. In this study protective measures watershed simulated stone lines, contour lines and mulching considered as a management solution. The best solution was contour lines by 17.89% reduced nitrate amount input to Urmia Lake see also 11.17% discharge the ground water.

Peoples’ participation in watershed development projects, in addition to reducing operating costs, can lead to more effective project implementation. Various factors causes the lack of public participation in watershed development projects. The purpose of this study was to identify, classify and prioritize these factors based on local people as well as experts viewpoints in Niarij watershed of Qazvin province. So first, these factors were identified and categorized based on the previous studies, interviews with experts, and residents and stakeholders of the watershed. Then,  pairwise comparisons and likert questionnaires were prepared as a measuring tool and the validity of the questionnaires was confirmed based on the opinions of the experts. In the next step, the sample size was determined by Cochran formula and the questionnaires were completed. Finally, the indicators and sub-indicators which preventing the participation of the people were prioritized using Fuzzy Analytical Hierarchy Process and Friedman Test. The results showed that, from the perspective of both groups of experts and peoples, management and economic indicators have a greater role in preventing people participation in relation to social and educational indicators. The results were also indicated some differences in the importance of the sub-indices from the perspective of the two groups. From the expertschr('39') perspective, "lack of full allocation of operating funds on time" and "local and tribal disputes" are the most and least important, respectively. But from the local communities point of view, the sub-indices " lack of stakeholders consultation in the design and development of projects" and "mistrust about the benefits of projects " are ranked as the most and least important, respectively. The overall conclusion is that factors such as stakeholder consultation, decentralization of decision-making from the headquarters, NGOs activities and training of local communities along with the considering the benefits of stakeholders, and multi-purpose projects can provide the basis for local peoples’ trust and will result in participation of people in the watershed development projects.

In natural resources, economic evaluation is poor in terms of study due to the uncertainty of non-consuming value of resources. In the present study, the evaluation of water, soil and plant resources in watershed management projects and expert questioning was done to enable the projects to be evaluated and prioritized economically. Three sub-watersheds were selected from the Parcel A watershed of Gheshlagh Dam basin in Sanandaj, that the mechanical, biological and biomechanical operations in each of them was executed. The amount of water, soil and plant resources of each project according to the guidelines of Forests, Rangeland and Watershed Management Organization was estimated. The ratio of income to cost and the cost of each unit of resources were obtained by calculating the value of each unit of resources and calculating revenues and costs in each project. Then, water, soil and plant economics as criteria and watershed projects as sub criteria were determined with paired comparison matrix questionnaires. A project has priority that protects more resources at a lower cost than another. Questionnaires were distributed among experts and data were analyzed by Analytical Hierarchy Process. The results of the expert questionnaire and the valuation of the sources were compared. The results showed that, the cost per cubic meter of water in the mechanical project is higher than biological projects, although experts prioritize mechanical methods economically but biological with an income-to-cost ratio of 2.2 is the top priority .The cost of water in the mechanical, biological projects was respectively 1.4, 1.2 times the price per cubic meter of water in the area. Soil and plant prices were also calculated and the biological project became the top economic priority. Therefore, priority should be given to biological projects that have less cost and more impact on resources, contrary to watershed experts and detailed-executive studies. As well as the mechanical projects should be limited to areas in critical flood situations, provided that operate biological projects in upstream.

Using the best management strategies (BMPs) is a useful way to control pollutions at the watershed outlets, which, of course, requires spending costs. Prioritizing these strategies (especially in areas with scarce resources) will greatly contribute to the efficiency and adequacy of these methods in terms of reducing pollution and their application in critical areas. In this research, the SWAT conceptual model has been selected as the simulating model, using the long-term data including meteorological, dam, agricultural management and Dez river flow. The results of SWAT model calibration and validation indicate that this model is reliable for simulating the Dez catchment area. These results were quite satisfactory for discharge, total phosphorus and nitrate, but not very suitable for sediment load. Also, the separation of the parameters affecting the variables, on the quality of the results of the calibration and validation has been desirable. Examining the modeling results in normal, wet and dry water years indicate more confidence in the results of the model in wet periods. Identification of critical areas has also been done with a single index methods based on the amount of pollution load produced in the basin, as well as three combined indicators. Finally, the practice of plant filtration is the most effective method in reducing the nitrogen load and the practice of increasing the D50 of soil particles is also the most effective method in reducing the phosphorus load. The sub-basin downstream of the city of Dezful, which has a major agricultural activities and included the sugarcane factory effluent, has been identified as the most critical sub-basin.

Saturated hydraulic conductivity of soil is an important physical property of soil that affects water movement in soil, Since the measurement of saturated hydraulic conductivity by direct methods in the field or in the laboratory is hard, time-consuming and costly, the indirect methods are being used.The aim of this study is to estimate the saturated hydraulic conductivity from other soil properties by using the Gene Expression Programming (GEP) method and some well-known pedotransfer functions and the Rosetta model, and then to compare their performances. A dataset including 151 soil samples obtained from a site in Bojnord province was used in this study. The soil properties used were sand, silt and clay percentage, organic carbon percentage, TNV, EC, saturated moisture, pH, bulk density and particle density. Modeling process using the GEP was done by using all of these properties as input parameters. The GEP model used only four properties, sand and silt percentages, bulk density and particle density, in its developed function to estimate saturated hydraulic conductivity. This model with RMSE=2.84 (cm/d) and R2=0.91 showed the best performance in comparison to the other pedotransfer functions. After the GEP, the Jabro (1992) pedotransfer function with RMSE = 4.74 (cm/d) and R2 = 0.82 was the best model in comparison to the rest of the pedotransfer functions and the Rosetta model. Saxton et al (1986), had the least accurate ks estimation among all methods. Since different data sets had been used to develop each of the pedotransfer functions and also because of high spatial variability of ks, there was a large difference between RMSE, MAE and MBE errors of the used methods. For the dataset of this study, the GEP model showed the best performance in estimating ks among other methods and its advantages were choosing model structure and important parameters to estimate ks.

LISFLOOD-FP belongs to a new generation of hydrodynamic models of flood simulation, which is implemented by a digital elevation map for the river and the waterways, route information and flow rates The LISFLOOD-FP features are two-dimensional hydraulic models: 1. based on raster 2. large scale 3. ease of formulation and high computational efficiency 4. simplicity of use 5. spatial adjustment of computations adaptively by the model itself 6. the ability to use the rivers with a width smaller than the dimensions of DEM pixels 7. the possibility of integration with fully distributed hydrological model such as WetSpa. These are the advantages of LISFLOOD-FP compared to other two-dimensional hydraulic models. Today, two-dimensional hydraulic models which are based on raster has become increasingly popular due to the development of personal computer processing capacity as well as ease of access to high-resolution topographic digital maps. The present study determined hydraulic behavior of flooding and water level in different return periods in Shemshak watershed using a LISFLOOD-FP two-dimensional hydraulic model. In this regard, the digital elevation model (DEM) was used with a spatial resolution of 2 meters. Finally, the data were entered into the model and analyzed. The results indicated that the model is efficient in floods simulation and showed that the river course is vulnerable against flood in one part of the main branch of Darbandsar and in the junction of Shemshak and Darbandsar in Dorood while it has less vulnerability in some other areas.

Identification of trend and drought characteristics play an important role in the development and management of water resources. In this study, the spatio-temporal characteristics of SPEI index in short, medium, long and annual scales (SPEI3, SPEI6 and SPEI9) in Urmia Lake basin were investigated. for this purpose, temperature and precipitation data from 4 synoptic stations of Tabriz, Urmia, Mahabad, Ahar during 26 years (1988-1983) were used. Mann-Kendall test and LOWESS graphical method on monthly, yearly scale were used to evaluate SPEI index trend. Drought trend increased in all synoptic stations studied and monthly SPEI index decreased in all three short, medium and long term time scales (drought increase).The annual drought trend at Mahabad Synoptic Station also increased drought, and at all three time scales the drought trend at Mahabad station was downward compared to other selected stations. Based on the annual results of the SPEI index, the longest humidity period from 1990 to 1995 is detectable. The most severe drought was in 2001 in Urmia and Ahar stations. Also, the longest drought period (moderate, severe, very severe) on the time scales is at Mahabad Station. and Mahabad station is the first priority in terms of increasing drought process and Urmia station is the last priority.

Inadequate productivity and over-capacity of land in many watersheds and plains of the country, has increased flooding potential. Therefore, reducing flood damage with the participation of both policymakers and the public as key stakeholders in decision-making, planning, long-term management and foresight in decisions are unavoidable. In the present study, SWOT analytical method was used to reduce flood potential and reduce flood risks in Hamedan- Bahar plain of Hamedan province in Siminehroud basin. To this end, the strengths, weaknesses, opportunities, threats to the method of precipitation, and the relative and final value of each of the SWOT evaluation matrix factors were assessed to determine the strategy for reducing the consequences of flood hazards. The final value of the matrix of all SWOT factors was 4.47, which indicates that strengths outweigh weaknesses. Also, the final value of external and internal factors was obtained as 2.51 and 1.96, respectively, which indicates that there are more opportunities than threats. These conditions indicate the establishment of a conservative strategy (WO) in the Hamadan-Bahar plain and the use of existing opportunities to reduce weaknesses. Finally, the two strategies of monitoring the construction of river banks and applying expert opinions in the implementation of land management laws along rivers and catchments with a weight of 0.761 ranked first in reducing the flood potential of the plain and reducing flood hazards.

One of the most fundamental processes, which influence climate and weather, both global and local scales that a fact which gives it the status of agriculture, is Evapotranspiration (ET). In irrigation and water resources management, ecosystem modelers, environmental assessment and solar energy system, accurate assessment of evapotranspiration is essential. Potential evapotranspiration (ET) has commonly applied to calculate the actual evapotranspiration, which was difficult to estimate by lysimeter measurement and water balance approach under field conditions. Until now, many methods have reported to estimating ET, however, due to the availability of the observed data, it is difficult to choose the optimal method. In this study, to determination of the best potential evapotranspiration method for the Khorasan Razavi Province, three temperature-based methods, Hargreaves–Samani (HS), Hamon (HAM) and Linacre (LIN) and five radiation-based methods, Jensen-Haise (JH), Makkink (MAK), McGuinness and Bordne (MB), Abtew (ABT), and Priestley–Taylor (PT), were compared with PM at yearly scale, using long-term (11-67 years) data from 13 meteorology stations. Indicators, viz. The correlation coefficient (CC), Relative bias (BIAS), normalized root mean squared error (NRMSE) and Relative error(Re) were used to evaluate the performance of ET estimations by the above-mentioned eight methods. The results showed that the performance of the methods in ET estimation varied among regions; ETLIN overestimated ET, while others underestimated. In Dargaz and Golmakan, ETHS yielded similar estimations to that of ETPM, while, in Torbate-jam and Khaf, ETLIN showed better performances. Also in Mashhad and Gonabad, ETHAM, in Neyshabour, ETJH and in Torbat-e Heydarieh, ETABT showed better performances. But in Fariman, Kashmar, Sabzevar, Sarakhs and Quchan, all methods showed poor performance. It indicated that ETPM is acceptable for ET simulation for the yearly timescale in these areas.    ​

Evapotranspiration is one of the most important components of the hydrology cycle for planning irrigation systems and assessing the impacts of climate change hydrology and correct determination is important for many studies such as hydrological balance of water, design of irrigation irrigation networks, simulation of crop yields, design, optimization of water resources, nonlinearity, inherent uncertainty, and the need for diverse climatic information in estimating evapotranspiration have been the reasons why researchers have used artificial intelligence-based approaches. In this study, to estimate accurately the daily reference evapotranspiration between 2009-2018 in Zabol city, north of Sistan and Baluchestan province,  first was used a standard FAO-Penman-Montith method and Zabol synoptic station meteorological data- the ETo reference transpiration is calculated and then presented by various scenarios of meteorological parameters including: maximum, minimum and mean temperature, maximum, minimum and mean humidity, precipitation, sunshine, wind speed and evaporation as inputs for deep learning models, Random forest and generalized linear model were attempted on a daily time scale More accurately. In estimating daily evapotranspiration in these models, 25 scenarios were selected from meteorological data combination and FAO-Penman-Monteith method was used to evaluate the models. Among the investigated scenarios, the M5 scenario (maximum, minimum and mean temperature, maximum, minimum and mean humidity, wind speed, pan evaporation) for deep learning model with minimum error (0.517) and highest correlation coefficient (0.517). 0.996 had the best performance among the above models. The deep learning model showed more accuracy and stability than other models. Hence, this study is recommended a deep learning model for estimating reference plant evapotranspiration in Sistan plain.

Global climate change as a main factor affecting all ecological components, has been attended by researchers all over the world in the recent years. In this regard for simulating the rainfall, National Centers for Environmental Prediction (NCEP) data, HadCM3 data under A2 and B2 scenarios, CanESM2 data under RCP2.6, RCP4.5 and RCP8.5 scenarios were utilized. This research was performed by adopting the Statistical Downscaling Method (SDSM) at Tabriz synoptic station over 31 years base periods included (1971-2001) and 35 years (1971-2005). According to the results of A2 and B2 scenarios simulation, the monthly rainfall mean will increase by 11.22 and 9.58 mm over the first 30 years period (2010-2039), 11.69 and 12.62 mm over the second 30 years period (2040-2069) and 12.77 and 13.10 mm over the third 30 years period (2070-2099) in the future, respectively. Additionally, the results of RCP2.6, RCP4.5 and RCP8.5 scenarios simulation demonastrated that the monthly rainfall mean will increase by 6.29, 7.59 and 7.53 mm over the first 30 years period , 9.28, 8.09 and 7.43 over the second 30 years period and finally 7.90, 10.50 and 7.08 over the third 30 years period in the future, respectively. We found that the most increased rates of the  rainfall mean under all studied scenarios will happen in March, April and May months due to global warming effects on rainfall amount and patern.

Determining the relative contributions of human activities and climate change to variations of runoff in basin is very important for sustainable management of water resources. In this study, seven methods were used to determine these relative contributions in the Ghaleh-Shahrokh watershed as the main upper catchment of Zayandeh-Roud River. These seven methods can be divided into two main categories, including empirical methods and elasticity-based methods. At first, Pettitt method was used to determine undisturbed and disturb periods of the runoff in the watershed and then relative contributions of climate change and human activities were determined by using the different methods. The results of this study show that the human activities play a dominant role in the reduction of runoff in the Ghaleh-Shahrokh catchment. According to the empirical and the elasticity-based methods, human activities account for 64.5 % (47 to 82%) and 76 % (70 to 89 %) of the total runoff decrease, respectively. Also, 35.5 % and 24 % of the total decrease in runoff in the catchment was due to climate change effects according to the empirical and elasticity-based methods, respectively. Generally, it can be concluded that the elasticity-based methods are better than the empirical methods in determining the contributions of human activities and climate change to runoff variations, because they take into account the evapotranspiration addition to rainfall and runoff.

Soil surface rock fragment is considered as an important factor on runoff and soil erosion. However, few studies have been focused on quantitative evaluation of the effect of soil surface rock fragments on runoff components as an integral part of soil erosion process especially in natural conditions. The present study has been conducted to evaluate the effect of soil surface rock fragments on runoff components in field plots under rainfall simulation on a clay-loam soil generally less than 1 meter depth and the slope of 20%. Runoff components including runoff commencement time, volume, coefficient and end time were measured in 1×1 m field plots with 6 wide range of surface rock fragments (2±2, 10±2, 18±2, 26±2, 34±2 and 42±2 % of soil surface cover) with 3 replications under simulated rainfall with constant intensity of 40 mm h-1. The results showed that increasing surface rock fragments up to a specific soil surface cover (about 34%) led to increase infiltration and runoff commencement time, decrease runoff volume and coefficient and runoff end time. The trend of runoff components has been reversed in the range of 34 to 42% of soil surface rock fragments.

Analyzing variability of measured runoff and soil loss data under different condition of measurement system, are critical for advancing erosion science, evaluating hydrologic models, and designing erosion experiments. For this purpose, the current study aimed to evaluate how runoff and soil loss are influenced by hillslope direction and length in Sangane arid rangeland, Razavi Khorasan Province, Iran. To achieve the goals of this research, 5 plots with length of 5, 10, 15, 20 and 25 meters were established on the north and south facing hillside. The analysis of 20 storms events causing soil erosion, indicted that one event produced about 70% and 34% of soil loss in southern and northern slopes, respectively. The results also, showed that in northern slopes duo to poor vegetation cover, hydrological response to subsequent rainfalls and hail are different from the northern slope. Finally, in current study, a decreasing non-linear relationship between area specific runoff and soil loss as well as plot length were founded.

One of the serious challenges in inter-basin water transfer plans is the existence of various complex which, due to their different roles and effectiveness in implementation, have caused many problems in the environmental, economical, cultural, social, technical fields.Therefore, the aim of this study was to identify and prioritize effective consequences in inter basin water transfer plans using the opinions of 41 experts and specialize expert faculty members in this field. In this regard, a researcher-made questionnaire was used to identify the effective and important consequences of inter-basin water transfer plans from three environmental, economic and social perspectives and the entropy technique was used to calculate their weight. In the following, the preferential technique based on similarity with the ideal solution (TOPSIS) was used to prioritize of effective consequences. The analysis of the findings of this study by completing the questionnaire identified 29 consequences (indicator) from environmental, economic, social aspects for inter-basin water transmission projects, including 9 ecological consequence, 7 economic consequence and 13 social consequence for evaluating inter basin water transfer plans. The results of weighing the consequences using the Entropy technique showed that the sociol consequence with weight (0.44744), environmental consequence with weight (0.31102) and economic consequence with weight (0.24153) among the consequences. From the environmental point of view of the destruction of swamp and wetland life downstream of the orgine watersheds consequence with weight (0.034655), economically point of view of heavy structural cost (pumping station, tunneling and piping, desalination, etc.) with weight (0.03462) consequences and socially the consequence of protests, disputes, social, ethnic conflicts, and discrimination in a society with weight (0.03465) have the highest weight among other consequences respectively. The overall results of this study indicated that the positive and negative consequences of inter-basin water transfer schemes must be considered by the water-related organization to monitor and maintain the sustainability of natural ecosystems and achieve sustainable development goals.

Although groundwater resources have long been selected as a safe choice for resolving human water requirements, overexploitation of them, especially at Ardabil plain, has promoted a decrease in the quality and quantity of these resources. One of the significant solutions is to identification of the groundwater potential zones and exploitation of them according to their potentials. The aim of this study was to compared the efficiency of two objective models: Index of Entropy (IE) and Naïve Bayes (NB) in groundwater potential mapping of Ardabil plain, located in northwest of Iran. For this purpose, ten groundwater occurrence factors including elevation, slope, soil, rainfall, distance from river, land cover, normalized difference vegetation index (NDVI), lithology, groundwater depth, and transmissivity were used based on the availability of data. In order to reduce subjectivity in groundwater potential modeling, all spectral groundwater data layers were classified into objective classes by using Jenks optimization technique. After computing groundwater potential index for the models, receiver operating characteristic (ROC) curve and the area under the curves (AUC) were implemented for validation of the models. The AUC values for the IE and NB models are 0.728, and 0.821, respectively. The overall results approved that both of the models have good capability for demarcating groundwater potential zones but the NB model performed better than the IE model for groundwater potential mapping in Ardabil Plain. The results of accurate groundwater potential mapping at Ardabil plain can be useful for groundwater resources management and avoiding overexploitation in the plain.

Hydrological models are simplified representation of the real basin system, which helps to assess basin function in response to different inputs and better understanding of hydrological processes. The HEC-HMS model is one of the most important hydrological models for Flood estimating volumes and discharge in watersheds. In this research, the HEC-HMS hydrologic model was used to simulate the runoff flow in the Sarbaz river basin in Sistan and Baluchestan province. For this, basin and sub-basins models were prepared using the Digital Elevation Model (DEM) map and using Arc Hydro and HEC-geo HMS extensions. Next, through integration of land use maps and soil hydrologic groups in the Arc GIS, the curve number map for the studied basin was obtained. The results suggest that this basin has low permeability and high runoff volume. The results showed that there is a good consistency between observed and simulated hydrographs at the basin outlet and values of model efficiency index at the validation stage with Nash-Sutcliffe efficiency and were 0.90 and 16.37respectively which indicates the high efficiency of the model in estimating peak flow in basins and sub-basins. Also, according to the results, in this basin, as returns period increases, the runoff volume and basin discharge will be increased.