حوزه آبخیز

Access to mineral resources is vital for humanity. Mining, along with agriculture, is a foundational industry that provides essential raw materials for electricity, steel, petrochemicals, and food production. However, the topographical and environmental changes resulting from mining, as well as their effects on human health and watershed management, must be addressed. Achieving a balance between these competing interests requires effective restoration and rehabilitation of mining sites. Current mining laws often permit exploration and extraction without sufficiently considering the rights and interests of local communities, leading to social conflicts and operational challenges. The findings indicate that mining in watershed areas faces significant issues, including economic and social resource depletion and raw material exports, alongside environmental destruction and harm. Additionally, mining often lacks social acceptance and support. Continuing with this approach will not benefit the mining sector

Check dams are simple and relatively low-cost structures that are widely used to control sedimentation in watersheds due to the lack of special materials and technology. These types of dams have the largest amount of watershed improvement operations in Iran. Therefore, considering the frequency of construction and as a result the cost of construction, it is necessary to investigate their performance in watersheds to identify their strengths and weaknesses. Evaluation of sediment trapping of check dams and correct selection of parameters affecting their sedimentation performance is the main goal of this research.

In this research, the evaluation of check dams from the perspective of sedimentation performance in the Nehzatabad watershed in Kohgiluyeh county has been investigated. For this purpose, after determining the parameters related to the volume of sediments deposited behind 11 selected check dams and calculating their volume, the amount of sediment yield was first measured and then estimated by calculating three different sediment trapping coefficients. Finally, by calculating the sediment delivery ratio, the measured and estimated sediment yield was converted into its equivalent soil loss on the surface in the upstream sub-watershed of the check dams.

The results showed that the amount of  specific sediment yield measured in check dams is from 0.001 to 1.08 and on average 0.13 tons per hectare per year. Considering the ratio of sediment delivery, which varied from 18 to 51 percent for selected dams, this amount of sediment yield is equivalent to 0.01 to 2.1 and an average of 0.3 tons per hectare per year of soil loss in the upstream sub-watersheds of check dams, which is a very small number compared to the figures presented for the average soil loss in most of Iran's watersheds. Taking into account different coefficients of sediment trapping, the estimated average values for  specific sediment yield in check dams are 2.88, 7.46 and 0.87 tons per hectare per year, which are equivalent to 9.41, 30.5, 3.49 tons per hectare per year of soil loss respectively, which compared to the average amount of soil erosion in Iran's watersheds, seem more reasonable and logical numbers.

Considering the factors affecting the sediment trapping coefficient, it can be said that if check dams are built at a point in the waterway where the ratio of the storage capacity of the dam reservoir to the area of ​​the sub-watershed upstream of the dams is higher, the sediment trapping coefficient in the dams will increase, which it is more favorable in terms of sedimentation efficiency. By examining the amount of sediment trapping coefficients in the investigated check dams in the Nehzatabad watershed, which are relatively low, it can be said that one of the reasons for the low coefficients is the reduction in the ratio of the storage capacity of the dam reservoir to the area of ​​their upstream watershed. Therefore, if the scientific principles are not observed in the correct selection of the effective parameters for the placement of check dams, the implementation of such projects does not have the necessary and sufficient effectiveness, while the sediment measured in these dams and the soil erosion equivalent to it are a basis for the implementation of other watershed management measures are in watershed areas and if they are not accurate, It can lead to ineffectiveness of these measures and incorrect calculations.

The comprehensive management of watershed resources is considered as a new principle for planning the development and management of water and soil resources with an emphasis on the social and economic characteristics of the region in order to provide a sustainable livelihood for the vegetation and users of a basin without vulnerability. Although each country has its own conditions, there are similarities in the challenges faced by watershed management, in particular water resource management. Therefore, it is important to examine the experiences of other countries. In this research, the experiences of comprehensive watershed management approaches at the national and transnational levels were reviewed. The main aim of these plans was to improve and preserve water and soil resources, taking into account the improvement of the livelihood of local communities. According to these studies, a comprehensive watershed management approach has resulted in achievements such as attracting people's participation in projects, protecting water and soil and preventing land degradation, increasing the income of basin residents, women's participation, reducing soil erosion, reducing pollution, etc. The use of successful experiences of countries and the presentation and implementation of the compiled model can serve as a guide for decision-making and action in the field of watershed management, thereby promoting the stability and development of the country's watersheds.

Measuring the amount of runoff and soil loss per unit area is very important to evaluate the condition of erosion in different areas. The runoff is caused by the condition of the upstream watersheds, which has a different response in different time and space ranges of a watershed. Some hydrological responses may be considerable in the upstream areas of a basin, but the same responses cannot be identified in the downstream. These different responses among different regions are referred to as the scale effect, including the mismatch among runoff responses at different scales. In this context, the role of spatial scale is considered as a factor that directly affects the occurrence of various processes of runoff production. Therefore, assuming the uniformity of discharge changes on different scales leads to the application of a single plan and management strategy for the entire watershed area, which ultimately results in the failure to achieve the desired outcomes. On the other hand, an accurate estimation of the discharge status of watersheds provides a correct understanding of the underlying hydrological processes. Comprehending the accurate influence of spatial scale on runoff is essential for precise streamflow estimation in watersheds and their zoning across various spatial extents. This forms the foundation for optimal water and soil resources planning and management, particularly in basins facing serious soil erosion challenges. Therefore, the objective of the present study was to examine the effect of spatial scale on the specific discharge and zoning of discharge values within the Karkheh basin, based on data of 28 hydrometric stations.

Materials and methods :

In this research, the data used includes the average annual water discharge (Q) and the area of the basin and sub-basins (A). The data used was received from the Iranian Water Resources Management Organization. Subsequently, in order to identify the most suitable stations, any disturbances in the natural process of the basin processes were initially investigated. This process involved the identification and removal of stations that had the potential to alter the process. Finally, a total of 28 stations with an appropriate statistical period length and no upstream basin disturbances were selected. Also, in order to calculate the upstream area of each station, the Karkheh basin was divided into 28 sub-basins based on the location of existing hydrometric stations. This was achieved using the Arc Hydro extension and the digital elevation model. In addition, according to the topographical, Geomorphological and hydrological conditions, the Karkheh basin was divided into five main areas.In the following, according to the values of area (A) and specific discharge (Qs) in the sub-basins, Qs-A relationships were drawn under log-log coordinates to calculate a linear or non-linear regression equation between Q and A, the effect of the scale onthe amount the discharge in the main sub-basins should be specified. Finally, using the method provided by Church et al., the corrected specific discharge values were calculated for each of the main sub-basins and through interpolation, the specific discharge map of the basin was produced.

The results of investigating the effect of scale on specific discharge indicated that there was no proper regression relationship between Qs and A for the entire Karkheh basin as a single basin (R2=0.3). However, the regression relationships with a coefficient of determination ranging from 0.7 to 0.98 were obtained for the sub-basins.Other results showed that in the majority of sub-basins, there is a negative relationship between area and specific discharge. That is, as area increases, specific discharge decreases. However, in the Seimareh basin, the increase in area leads to an increase in specific discharge. The observed increase in discharge can be attributed to the reduction in the basin elevation and the broadness of the riverbed. In contrast to other sub-basins, the discharge in the Qarasu sub-basin exhibits a low initial value, followed by an increase and subsequent decrease. This phenomenon can be attributed to the location of the Qarasu sub-basin in the upstream region of the Karkheh basin, the topographical conditions, and the high slope of the area. In general, the results indicated that the specific discharge varies across sub-basins with different areas and spatial scales. So that, the highest specific discharge was observed in the vicinity of the Karkheh basin outlet. This can be attributed to a number of factors, including the high slope and rainfall intensity in the upstream areas, as well as the difference in climate conditions and vegetation cover between the downstream and upstream areas.

Conclusion :

A comprehensive understanding of river discharge and the impact of spatial scale on it is of paramount importance in various fields. It provides a profound insight into the consequences associated with this phenomenon. To sum up, it is critical to understand river discharge patterns and how spatial scale affects them in a variety of contexts, including water resource management, flood risk reduction, sustainable development, and environmental preservation. It gives us a thorough awareness of the resulting effects. The findings of this study indicate that as the area increases, the specific discharge tends to decrease. Based on these results, it can be inferred that spatial scale and the upstream watershed area can exert an influence on discharge. A substantial body of research has demonstrated that spatial scale and the upstream watershed area play a pivotal role in determining river discharge. However, it is crucial to acknowledge the influence of a multitude of factors, including vegetation cover, climate, topography, slope, soil infiltration, and precipitation intensity, on specific discharge across diverse watersheds. Therefore, when evaluating the hydrological conditions of large-scale watersheds, it is essential to pay particular attention to the impact of spatial scale as a crucial factor. It is noteworthy that recognition this phenomenon necessitates more in-depth and comprehensive investigations across various spatial scale levels.

Water and soil resources are the most important factors in the production of energy needed for humans. In order to protect water and soil resources, different management methods are applied according to the conditions of each region. The participation of all watershed residents and changing their behavior will be one of the basic tools of any sustainable management plan. Since norms affect the participation and behavior of local communities; the purpose of this research is to investigate the norms affecting the participation and behavior of watershed residents in the implementation of water and soil protection projects.

This research was done by descriptive-analytical method. For this purpose, Benchele watershed in Ravansar city was selected as the study area. A questionnaire was used to collect field data. The statistical population of this research was all heads of households of watershed residents in this area, numbering 569 people. Among them, using Cochran's formula and matching with Morgan's table, 229 people were directly questioned by simple random method and completed the questionnaires. Spearman's correlation tests and stepwise regression were used to analyze the data. The focus of the questions was focused on three independent variables (legal norms, normative beliefs and participatory norms) and two dependent variables (participation and behavior of watershed residents). In the data analysis section, descriptive statistics (frequency, percentage, average, etc.) and inferential statistics (Spearman's correlation test and step-by-step regression) were used. Before performing the regression to check the collinearity test, the degree of collinearity of the independent variables was examined. Also, standardized beta values were used to determine the relative importance of each independent variable in the participation and behavior of watershed residents.

The mean ranking results of each of the items of legal norms affecting the participation and behavior of watershed residents in water and soil protection projects show that the items of "people who damage water and soil resources should be fined" and "existing laws are useful to convince people in the field of protecting water and soil resources" have the greatest and least impact on legal norms with the participation and behavior of watershed residents, respectively. The results of the mean ranking of each of the items of normative beliefs affecting the participation and behavior of watershed residents in water and soil protection projects show that the highest ranking average is related to "society expects me to take care of water resources" and do not destroy the soil" and the lowest rating is related to "experts expect me not to destroy the soil". The mean ranking results of each items of the participation norm effective on the participation and cooperative behavior of watershed residents in water and soil protection projects show that from their point of view, the item "voluntarily participates in the construction of sediment dams" and the statement "I am willing to pay for the implementation of water and soil protection projects", respectively, have the greatest and least impact on the participation and behavior of watershed residents in water and soil protection projects. The results of Spearman's test showed that all three independent variables of legal norms, normative beliefs, and participatory norms have a positive and significant relationship with the participation and behavior of watershed residents. Also, the regression results and beta values showed that, respectively, the indicators of legal norms, normative beliefs, and participatory norms had the highest priority in the participation and behavior of local communities.

The results showed that about 66% of watershed residents have moderate to low participation and cooperative behavior. The mean ranking results of each of the watershed residents' participation and their behavior to participate in water and soil protection projects show that the watershed residents' care of the projects after its completion, participation in the mortar dam construction project Mortar-cement dam has the greatest effect on their participation and cooperative behavior. Also, the items of participation in the construction of gabion dam project and the desire and intention of watershed residents towards water and soil protection had the least effect on the participation and behavior of watershed residents towards water and soil protection. In general, paying attention to the norms, beliefs, behaviors and attitudes of local communities should be on the agenda of managers and planners to pave the way to protect water and soil resources.

In most of the countries of the world, both developed and under-developed, applied and developmental research in various economic and social sectors, including agriculture and natural resources is very important. To implement executive projects based on the results of research over the past years based on predetermined goals, financial, resources and relatively appropriate facilities in the agriculture and natural resources sector, including the watershed sector, have been considered and spent. Nevertheless, it has always been accompanied by many discussions from supporters and opponents. This article is the result of a study to evaluate the effectiveness of watershed management projects implemented based on the results of research in the Chandab Watershed of Tehran Province. which includes effective, flood distribution, rain catchment surface system, catchments, underground dam, water supply channels, flood expansion channels, and sediment catchment in this area. To investigate this issue, research projects based on solving the problems and issues of the study area, and the results in the form of watershed management plans and projects to control runoff and soil erosion, improve the condition of vegetation, and finally improve the economic and social status of watershed residents in the operational area have been implemented.

To investigate this issue, research projects based on solving the problems and issues governing the study area, and their results in the form of watershed management plans and projects to control runoff and soil erosion, improve the condition of vegetation, and finally the improvement of the economic and social status of watershed residents in the region has been operationalized and implemented their identification and effectiveness in achieving the set goals of watershed management have been studied and analyzed from an economic and social point of view. This study is a descriptive and descriptive type, and the data required for the research was collected in the field by filling out the questionnaire from the residents and beneficiaries of the studied watershed and reviewing the financial reports for the expenses incurred. Before completing the questionnaire, its reliability and validity were measured using Cronbach's alpha coefficient. The estimated alpha coefficient was 0.87, which indicates integration and coordination in the framework of the questionnaire. Then, the present value of the cost and income during the period was estimated. The benefit-cost method (B/C), rate of return and profit, satisfaction level, and economic efficiency index have been tested and analyzed.

The results of the research showed that the farmers and villagers living in the studied watershed are fully satisfied with the implementation of the underground dam projects and watershed flood distribution catchments, and the implementation of these projects in the state of the watershed in terms of improving vegetation, control Floods, development of agriculture, animal, husbandry and improvement of income and livelihood of villagers have had significant positive effects. The selected projects implemented are economically and socially effective and have economic and social, justification. Thus, the benefit-cost ratio is estimated at 1.85 units, and the economic efficiency index is at 0.85 units.

The study results show that the watershed projects implemented in the study area are economically and socially effective. From a social, point of view, most of the users living in the studied area are fully satisfied with the implementation of watershed management projects. Considering the economic and social justification of watershed management projects, it is recommended to develop the implementation of watershed management operations in this and other watershed areas. For the local, people to benefit from the achievements of these projects and also to satisfy the local, people from the previous projects, it is suggested that these projects be carried out within the boundaries of the land of the beneficiaries so that the maximum participation of the beneficiaries is realized. To provide the possibility of entrusting the maintenance of watershed operations in watershed areas to the local, people and users with a specific and defined mechanism.

A spatial survey of the degree of vulnerability is an important step in order to identify vulnerable areas and make decisions to protect natural resources and achieve sustainable development. Therefore. the present research the present study was conducted with the aim of spatially investigating the degree of vulnerability of Dorodzan Dam watershed in Fars’s province with a climatic approach.

Climatic data of 9 climatology station in the period 1991-2020 was used. indicators affecting the vulnerability of the watershed were extracted. including wet season. dry season. cold season temperature. hot season temperature. maximum wind speed. and height above sea level. After determining the aforementioned indicators. the overall vulnerability index (OVP) was calculated.

In this method. vulnerability indicates the performance. nature. rate of climate change in the watershed.  The results showed that the dry season index ranged from 6.40 to 66.19 mm for Chamriz and Emamzadeh Ismail stations and the wet season index ranged from 70.67 to 538.03 mm for Eghlid and Chamriz is variable. Also. the cold period index was 1.77 to 2.65 °C for Dorodzan and Zarghan stations. respectively. and the warm period index was 1.52 to 2.21 °C for Chamriz and Zarghan stations. respectively. The maximum wind speed index was calculated between 0.08 and 0.85 km/h for Eghlid and Dorodzan stations. respectively.  Altitude was also assessed.  The results based on the analysis of climatic indicators show that the total vulnerability index in the Dorodzan dam reservoir is between 25.7 to 34.2 and fall within reversible class.

Given the results obtained and considering the good Potential of this watershed. the need to consider management and preventive measures against drought and flood threats caused by climate change and human change is important. Considering that according to the standard of the mentioned method. the index is less than 40 in the reversible range. therefore. according to the location of the vulnerability index of the studied area with the climatic approach. it can be concluded that although the region has undergone many changes especially in recent years however. due to the slight changes in climatic indicators in the long term. this watershed is still far from the limits of resilience from physical aspects. and with the adoption of suitable management patterns. it has the ability to return to ideal conditions.The results of the research. in addition to expressing the importance of the effects of climate change. will help their application in the application of correct and compatible management with climate change in future watershed management policies.

The development of agricultural and urban areas and overexploitation of natural resources have caused significant changes in the hydrological regime of watersheds. Furthermore, population increase, unprincipled exploitations and climate changes have intensified this process. It is therefore necessary to know and study it continuously. The trend of hydrological series may also change due to climate change, land use and watershed management. Therefore, identifying the presence or absence of changes in time in rainfall and discharges of an area and presenting it in statistical analysis seems necessary. The Mann-Kendall test is one of the most widely used nonparametric methods for analyzing the flow of such data. Studying periods of rainfall and discharge as well as land use change can be useful in expressing the role of climatic and human factors. Therefore, the present study was conducted to investigate the trend of land use change and the role of each in the discharge trend of Kiar watershed. 

The present study was conducted in Kiar watershed located in Chaharmahal and Bakhtiari province as one of the northern sub-basins of Karun River. In order to conduct the current research and achieve the desired goals, after obtaining the information and data required for the research from the Chaharmahal and Bakhtiari Regional Water Organization, a joint statistical course of study stations was determined. Finally, the mentioned period was selected from 1363-1390. Then, Mann-Kendall non-parametric test was used to investigate the trend of changes in precipitation and discharge of stations in Kiar watershed. Then, land use changes in the study area in three time periods were extracted using the object-oriented classification method in IDRISI Taiga 16.03 software environment using Landsat's TM sensor images. Using the parameters of overall accuracy and kappa coefficient, the accuracy of the classification was calculated. Finally, the trend of land use change and its relationship with the trend of discharge were evaluated.

The results of trend analysis for the Dey River time series (on seasonal and annual scales) at the Burnt Mountain Station show that discharge has had a decreasing trend on both scales. The highest discharge trend in the seasonal series belongs to summer and the lowest discharge trend belongs to fall at the significant level of 1%. The study of trends in the rainfall time series of the region shows a different behavior. While the trend in Borujen station was upward, Shahrekord and Beheshtabad exhibited a downward trend, and no trend was found in Farsan station. The decreasing trend of discharge and precipitation in Kuh-e-Sokhteh hydrometric station and rain gauge stations in Shahrekord and Beheshtabad are on the same side, which can be attributed to the decrease in discharge due to the rainfall behavior of the region. The results of the trend of land use change showed that residential and agricultural lands have an increasing trend and rangeland and barren lands have a decreasing trend. Increasing the level of agriculture and residential areas can be a reason for reducing the trend in discharge.

Based on the results of the present study, the results of trend analysis for the time series of the river at the burnt mountain station showed that the discharge trend in seasonal and annual scales is Downward. The highest discharge trend in the seasonal series belongs to the summer season and the lowest discharge trend belongs to the autumn season. Also, the results of studying the trend in the time series of rainfall in the region showed different behaviors. While, the trend in Borujen station was upward, Shahrekord and Beheshtabad exhibited a downward trend, and no trend was found in Farsan station.

The development of the cultivation of medicinal plants in sloping lands based on public participation has an important role in improving land productivity, employment status, and livelihood of communities. The aim of this study was to investigate the barriers to the participation of local communities in the project of cultivation of medicinal plants in the sloping lands of Chehel Chay watershed in Minoodasht County. The research was descriptive and survey. The statistical population was 350 people from local communities living in the watershed. Using Krejcie and Morgan's table and random sampling method with assignment, 184 of them were selected as the research sample. The data collection tool was a questionnaire whose validity was confirmed by experts and its reliability was obtained by calculating Cronbach's alpha at the rates of 0.74, 0.79, and 0.89 for social, economic, and organizational barriers, respectively. Data were analyzed using SPSS19 software. The results of the Spearman test showed a positive and significant relationship between organizational barriers to participation with the variables of the number of years of employment in agriculture, hours of listening to the radio and watching TV during the day, and negative and significant relationship with variables of the number of respondents traveling to the city per month, the relationship between respondents and extension worker per month and the number of medicinal plants cultivated by respondents. Also, the results of the Friedman test showed the importance of organizational barriers in the non-participation of respondents in the project of cultivation of medicinal plants. It is recommended to pay attention to teaching the cultivation of medicinal plants to local communities, more communication, and interaction of extension workers with them, providing inputs and creating a suitable market for medicinal plants.

In the present study, the ARC SWAT model in ARC GIS software was used to model the Zolachai watershed in the city of Salmas (Chehric Alia). For sensitivity analysis, calibration, SPSS statistical software was used. In the model used from precipitation data, minimum temperature, maximum temperature and daily relative humidity of rain gauge and synoptic stations in the study area for 35 years (1984 to 2019), for five statistical periods of 7 years, for April, October and November used. To calibrate the ARC SWAT model in SPSS statistical software, indices of uncertainty, coefficient of determination, standard deviation, significance level and Fisher-in-law coefficient were used. The results of the uncertainty index for April, October and November were 0.8, 0.30 and 0.5 percent, respectively, and the watershed determination coefficient index for these three months was 0.0114, 0.5788 and 0.1551, respectively. Showed the percentage the standard deviation index was 0.97 percent for April, 07.07 percent for October and 1.09 percent for November. Significance level index for these three months showed 0.87 percent Fisher Sandkor coefficient as one of the important indicators of watershed validation for each quarter showed a number of 0.91 percent.

During the last two decades, there has been a lot of research on the base flow issue in the country, but so far, no comprehensive and specific article review of base flow research has been conducted, untill the various aspects of this issue be identified and the cases ignored, be introduced and addressed. In this research, first, by literature review at the global and national level, the progress of studies in different fields of this issue were investigated and then dissertations, articles and reports published in international journals and related conferences have been classified and discussed for the past two decades. The main purpose of this research was to identify issues of research at base flow and to identify lesser and overlooked issues in country research. The articles reviewed in this research were analyzed based on spatial domain, research method, theory, data analysis techniques and topic. Results showed that research orientation in base flow in Iran can be divided into four general categories; 28.21% of studies related to applied orientation; 37.18% to comparison and introduction of proper baseflow separation method; 19.23% to investigation of factors affecting base flow and 15.38% to general use and description of hydrological conditions of the study area. The overall conclusion, indicates limited studies, lack of innovative, and focus on the use of conventional and repetitive methods and also lack of attention to this issue by scientific and research centers of the country.

Every year, floods destroy the economic and social structure of communities and cause a lot of financial and human losses. One of the effective factors in the occurrence of floods is the development of urbanization around rivers. Due to climate change, in recent decades, Sistan and Baluchestan Province with hot and dry climate, is prone to floods. The aim of the present study is to zoning the flood of Sarbaz Watershed using HEC-RAS hydraulic model. To conduct the research, the SCS model of the area was first determined according to satellite images, land use map and runoff curve number. Then, the flood discharge of the basin with 10, 25, 50 and 100 years return periods was simulated using the HEC-HMS hydrological model. The simulation results resulted in the occurrence of peak flood discharges of 3363.8, 4563.7, 54462 and 6359.3 m3s-1 for return periods of 10, 25, 50 and 100 years in the study basin, respectively. In order to evaluate the efficiency of the model in calibration and validation stage, Nash-Sutcliffe evaluation indices and the mean square error were used, the results of which indicate the optimal performance of the model. Then, the flood zoning map of Sarbaz Watershed in Rusk City was prepared in desired return period with the help of HEC-RAS hydraulic model. The results showed that with the return periods of 10, 25, 50 and 100 years, 366.86, 397.12, 449.95 and 580.78 hectares of flood zone of Sarbaz Watershed in Rask City area will increase, respectively.

Due to the flow regime and consequently the sediment regime are not constantly in the watersheds, the prediction of sediment discharge is a great help in estimating and managing the sediment input to hydraulic structures. Measurement of sediment in the usual way is not justified in nowadays and may also lead to human error. Therefore, in this study, three meta-heuristic optimization algorithms, including imperialist competitive algorithm (ICA), grey wolf optimizer algorithm (GWO) and election algorithm (EA), were used to predict the suspended sediment load of the Zarrineh river. In order to calculate the sediment discharge by the models, firstly, the necessary statistics and data were collected from the studied station in the period 1993-2015. After processing the data, 210 corresponding discharge and sediment data were selected. The corresponding discharge-sediment data from the study station were randomly separated into two parts, 70% for training and 30% for testing. In order to evaluate the performance of the algorithms, four statistics consist of R2, RMSE, MAE and the NSE were used. The results showed that GWO algorithm with values of statistical criteria R2=0.96, RMSE=228.86 ton/day, NSE=0.74 and MAE=67.32 ton/day, has a very high accuracy compared to other algorithms used which this would lead to comprehensive planning for the design and construction of hydraulic structures.

Most of the rainfall in arid and semi-arid regions, which becomes runoff immediately after rainfall, eventually evaporates and becomes inaccessible. Harvesting water from impermeable rock surfaces and storage in reservoirs or aquifer feeding is an effective way to prevent evaporation losses in these areas. The purpose of this study is to model the amount of runoff in sub-basins with impermeable surfaces in the Haft Bagh Alavi area of Kerman to estimate the volume of harvestable runoff in this area. Haft Bagh Alavi watershed is located 26 km from Kerman and has an area of 14923 hectares. About 18.3%, equivalent to 2732 hectares of the basin area has a rock mass level of more than 90%. HEC-HMS software has been used to model rainfall-runoff in the basin. The area curve number of soil, slope, and land use information was entered into the model. 30-year mean evapotranspiration data, with the 30-year mean of 10-minute precipitation data, were collected from the automatic station and used as input. The results showed that by harvesting only 10% of the total average annual cumulative runoff of four sub-basins, it is possible to collect 8.055 million cubic meters of water and provide water for supplementary irrigation of 16,110 hectares of gardens.

Watershed practices play an important role in managing soil and water resources. On the other hand, the technical complexities and social issues of watershed projects have made it difficult to assess them. Quantitative and qualitative of socioeconomic evaluation methods both have strengths and weaknesses. Their combination can be effective in solving project evaluation problems. This research has been conducted to investigate the social and economic effects of watershed operations and collect the beneficiarieschr('39') viewpoints about these plans in Hasan-abdal basin in Zanjan Province. The method of this research is Descriptive and Analytical. The statistical population of this study consisted of heads of rural households residing in Hassanabdal basin (N=205) and based on the Morgan Table, 162 persons were selected using the cluster random sampling. A questionnaire was used to collect field data. The X2 test in SPSS20 and BCR and NPV economic analysis were used. The most significant impacts of the project are reducing the tendency to migrate, flood control, increasing the volume of groundwater, converting the low-yield drylands to the pasture lands, increasing the agricultural and garden products and reducing the costs. Implementation of watershed management plans in this area has not been effective in improving the social capital of the village, including increasing the participation and trust, raising the level of knowledge and skills of the people, increasing the income, increasing the employment opportunities and increasing the vegetation. The useful life of the research is estimated to be around 25 years, and the discount rate of 16% with the cost-benefit analysis of the data obtained in this period is greater than 1. The net present value of 1.062 indicates the plan is economically justified.

At present, there are a variety of reliable and practical methods for measuring soil moisture from point to world scale. Recently, remarkable progress in remote sensing techniques has allowed the scientific community to accurate and repeatedly map soil moisture anywhere in the world. The above points out the need for this research. In this research, this is the hypothesis, Do MERRA-LAND remote sensing data have an acceptable accuracy in determining the soil moisture content of the baft watershed? To answer this question, After downloading the data and reading them, Pearson correlation method was used to validate the data between monthly average remote sensing data and monthly average precipitation of baft synoptic and Kiskan Rainfall stations measurement in 2009-2013. The results showed 99% confidence in the Kiskan station and 95% confidently at the baft station There is a high correlation between monthly average soil moisture content downloaded with average monthly rainfall, Then, to compare the mean of MERRA-LAND data from the Goddard earth science(GES DISC) As predicted data at the specified date and time and the percentage moisture content obtained from 14 sampling points from the soil surface and the root zone area in the baft basin, the same time and date was used as in-situ data. Mean comparison of T-pair method was performed in SPSS software for each sample. The results showed that due to the higher T calculated from the table T with a degree of freedom 13 compared to the moisture content of the surface area and the root area there is no significant difference with surface download data and root area with 99% confidence. And can be recommended to the executive department Instead of spending a lot of time and cost Use the percentage moisture content provided by this site to predict and monitoring agricultural drought.

Tectonic activity affects the formation, deployment and evolution of  landforms as well as erosion processes. The existence of several faults and anticline in the west of Khuzestan Plain has also led to changes in morphology and the establishment of landforms such as sand dunes. Therefore, the research is aimed to determine the effect of tectonic activities on the morphology and behavior of sandy hills in west of Khuzestan Plain. To achieve the above goal, the following information layers were provided. The layers included Ahwaz geological map with a scale of 1: 100,000 and a topography of 1: 25000, field observations, as well as results from the processing of Landsat satellite images and IRS from 1991, 1998, 2002 and 2006. In addition, other GIS layers was used such as faults, anticlines and units, geomorphic units, sedimentary environments and drainage networks. Data analysis was also conducted based on field observations and geomorphic techniques and a comparison method. The results of geomorphologic indices such as coefficient of sinousity and integral hypersometry showed that the study area was strongly influenced by tectonic activity and morphotectonic units such as Hamidyeh-Ahwaz, Zeynol Abbas and Abol Gharib anticlines. However, other secondary factors such as the wind direction and the pattern of the flow of the Karkheh River, change the overall trend of sand dunes. It also causes sediment transfer from sand dunes to flood plains and dust production centers in the west of Khuzestan Plain. Therefore, the findings of this research can lead to the provision of necessary information for soil protection against wind erosion in the province, especially in the center of number one dust (Hooralazim), erosion and sediment sources along the Karkheh River Basin.

The sediment load estimation is essential for watershed management and soil conservation strategies. The sediment rating curve is the most common approach for estimating the sediment load when the observed sediment records are not available. With regard to the measurement errors and the limitation of available data, the sediment rating curve has a degree of uncertainty which should be accounted for. Thus, in this work, a stochastic Monte-Carlo simulation approach was employed to measure the degree of uncertainty and to analyze the sensitivity of sediment rating equation to changing the coefficients "a" and "b" at the Zoshk hydrometric station. Results of the Monte-Carlo simulation using 5000 samplings showed that in the hydrologic regimes of normal high flow, normal low flow and normal, the contribution of the coefficient "a" to variance is significantly higher than the contribution of the coefficient "b" to sediment load variance. However, this condition is conversely for the hydrologic regime of maximum flow. The sensitivity analysis confirmed a higher sensitivity of the sediment rating equation to the coefficient "a" than that to the coefficient "b" in the hydrologic regimes of normal high flow, normal low flow and normal. However, in maximum flow, the sediment rating equation showed a higher non-linear and more regulated sensitivity to the changes of the coefficient "b" than "a". In all flow regimes, the coefficient "a" has a wider 95% uncertainty band, in comparison with that for the coefficient "b", which establishes a higher level of uncertainty. The sediment rating equation showed a high degree of uncertainty in the hydrologic regime of minimum flow (lower than 0.3 m3.s-1). In this condition, all observed sediment records place outside the 95% and 97.5% of the uncertainty band. However, in medium and high flows, most of the observed sediment records are bracketed by the uncertainty band of 95% and 97.5%.