Mohammadjafar Soltani; Amir Sarreshtehdari; Samad Shadfar
Abstract
Inadequate temporal and spatial distribution of precipitation in arid and semi-arid regions, cause destructive floods in addition to loss of surface runoff. Therefore, controlling surface runoff and its proper utilization through the construction of rainwater catchment systems can be a good way to prevent ...
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Inadequate temporal and spatial distribution of precipitation in arid and semi-arid regions, cause destructive floods in addition to loss of surface runoff. Therefore, controlling surface runoff and its proper utilization through the construction of rainwater catchment systems can be a good way to prevent water loss. Traditional methods may be time wasting and concise. Geographic information systems provide new methods and models of using huge number of maps and data for analysis in a short time with best results and conciseness. This project was implemented in Kan Basin as a pilot which covers an area about 197 km2. Different maps including slope, land use, precipitation, vegetation cover, soil hydrologic groups and geology were overlayed. Land use maps were extracted from ETM+ 8 satellite images of 2014 along with field controls. Then layers were weighted according to their importance and role of each map. Suitable areas for establishing rainwater catchment systems in each model were determined by overlaying in the frameworks of different models including Boolean logic, Index overlay and Fuzzy logic and compared with control points which were implemented with Ministry of Jihad Agriculture. The results showed that the operators gamma=0.2, gamma=0.3 and Product from Fuzzy logic model had the most overlap with the control areas, the best integrated model for determining the appropriate locations for the construction of rainwater catchment systems in the study region.
Afshin Partovi; Hamidreza Peyrowan; Samad Shadfar; Fazel Iranmanesh
Abstract
Land cover change is one of the most effective factors of environmental change. So, understanding and predicting the causes, processes and consequences of land cover has become a major challenge. The remote sensing and satellite data technologies can be used effectively to detect and quantify land cover ...
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Land cover change is one of the most effective factors of environmental change. So, understanding and predicting the causes, processes and consequences of land cover has become a major challenge. The remote sensing and satellite data technologies can be used effectively to detect and quantify land cover changes and its effects on the environment. This research used the MODIS MCD12Q1 yearly data at 500 m resolution to evaluate the spatio-temporal changes in the national land cover of Iran from 2001 to 2015 in five years periods. Land cover maps of Iran were generated based on 12 classes for years of 2001, 2005, 2010 and 2015 and then evaluated using “Landcover Change Matrix”. Areal distribution analysis showed that the most parts of Iran covered by barren areas (more than 60%). The area of forests, croplands and grasslands were reduced from 0.8, 4.8 and 21.4 percent respectively in the year of 2001 to 0.6, 4.5 and 20.9 percent of Iran’s area in 2015. Furthermore, to evaluate land cover changes in five years’ period, the land cover map of the first and last years of each period were compared using “Landcover Change Matrix”. Results showed that in the five years periods of 2001-2005, 2005-2010 and 2010-2015 land cover of Iran changed increasingly as 2.13, 3.25 and 3.30 percent respectively of Iran’s area. And the overall changes of land cover in Iran from 2001 to 2015 is 6.08 percent of Iran’s area.
Davood Nikkami; Samad Shadfar
Abstract
Soil, as one of the components of any ecosystem and an important source of food production, has a very serious role in the continuation of human life. Therefore, the need to support and protect the soil and prevent its erosion is essential. Regarding the amount of soil erosion and sediment yield in the ...
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Soil, as one of the components of any ecosystem and an important source of food production, has a very serious role in the continuation of human life. Therefore, the need to support and protect the soil and prevent its erosion is essential. Regarding the amount of soil erosion and sediment yield in the country, different figures have been mentioned and in some studies, the difference is with several times. These figures vary from less than one to more than five billion tons per year. Therefore, calculating and plotting erosion and sedimet yield maps provides important information that is used in the design of dams, reservoirs, canals, soil protection operations, onsite and offsite erosion damage assessment, and land use planning and land capability assessment projects. Soil erosion map is one of the basic, scientific and applied maps in various executive, research and educational sectors. Due to the need of determining the amount of soil erosion and sediment yield for the entire country and determining the executive priorities in areas with high soil erosion potential, this project was defined and carried out by the Soil Conservation and Watershed Management Research Institute. Accordingly, the watersheds of the seventh category were divided into seven regions or districts, including 1) Eastern Alborz 2) Middle Alborz 3) Western Alborz 4) Central Iran 5) North Zagros 6) Middle Zagros and 7) South Zagros. Long-term sedimen data of 118 hydrometric stations in these areas were analyzed and the amount of sediment in each station was determined by the logged mean load within discharge classes method. According to the amount of river bedload rates and using EPM model, the amount of sediment yield and cosidering sediment delivery ratio of watersheds, the amount of soil erosion were etermined and the soil erosion map of watersheds overlooking hydrometric stations was prepared. Results showed that the average sediment yield and soil erosion in the watersheds overlooking hydrometric stations are 3.3 and 16 tons per hectare per year, respectively. The lowest and highest soil erosion rates of 9 and 32.4 tons per hectare, belong to the Middle Zagros and South Zagros regions, respectively.
Saeed Nabipay Lashkarian; Mahmood Arabkhedri; Samad Shadfar
Abstract
Accelerated soil erosion and the production and transfer of large amounts of sediment are considered as one of the most important issues in many parts of Iran. Having enough knowledge on soil erosion and sediment production as well as identification of critical areas are necessary in order to reduce ...
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Accelerated soil erosion and the production and transfer of large amounts of sediment are considered as one of the most important issues in many parts of Iran. Having enough knowledge on soil erosion and sediment production as well as identification of critical areas are necessary in order to reduce the adverse effects of this problem through soil and water conservation measures. Due to lack of gauge stations in the outlets’ of small watersheds, empirical models are considered as the proper tools for estimating soil erosion and sedimentation. One of these methods which was developed based on Meditranean sediment data, is the Factorial Scoring Model (FSM). Towards this, the main objective of this research is to compare estimated vs. observed sediment yields in some selected regions of Iran. For this purpose, 58 small chatchments equipped by reservoirs in their outlets were selected in Semnan, Central, Isfahan, Chaharmahal and Bakhtiari, West Azarbaijan, Lorestan, Fars, Golestan and Khorasan Razavi Provinces. The comparison of the results showed that all estimates of the original model (before calibration) are several times bigger than observed values obtained by surveying (0.44 to 459.44 t.km-2.y-1). In order to correct the model coefficients for Iran, calibration was performed in two scenarios; once using all data and in the second secenario after allocating data into three geographic regions, which in both cases resulted in significant improvement of estimates. The Nash‐Sutcliffe Efficiency coefficient for all catchments was 0.39, and for Central, Zagros and Northeast regions were 51.1, 0.66 and 0.78, respectively. Based on obtained findings, the application of original FSM must be avoided in study areas. Instead, we strongly recommend using calibrated models based on observational values for different geographic regions.
Seyed Masoud Soleimanpour; Majid Soufi; Mohammad Javad Rousta; Samad Shadfar; Ladan Jowkar; Hojatollah Keshavarzi
Abstract
Gully erosion is one of the main types of water erosion and is known as one of the destroying forms of land degradation and soil loss in the world. Therefore, knowing the most effective factors on extending this type of erosion is utmost important. Beside, management and control of gully erosion require ...
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Gully erosion is one of the main types of water erosion and is known as one of the destroying forms of land degradation and soil loss in the world. Therefore, knowing the most effective factors on extending this type of erosion is utmost important. Beside, management and control of gully erosion require knowing the most effective factors on gullies extension. So, the present study was performed to determine the most effective factors on gullies in Khorrambid Watershed, North of Fars Province through measuring the permanent gullies during 13 years (2004-2016). Results showed that the average of gully length extension was 21.67 m throughout this period. This data indicated that the length of gully extension was 1.67 m per year. Further, it is determined that the length expansion of permanent gullies in this region was a function of bare soil and saturated electrical conductivity, using SPSS and backward multivariable regression. In conclusion, it is suggested different management solutions to increase the soil resistance against the erosion be prioritized in management and implementation plans such as increasing adoptable cover vegetation for the natural condition of the region and exclude the area to restore vegetation cover and pay more attention to control erosion in gully head cuts.
Mosayeb Heshmati; Yayah Parvizi; Mohamad Gheitury; Mojtaba Sanee; Samad Shadfar; Masud Goodarzi
Abstract
Abstract: land degradation, air pollution, food deficient, poverty as well as inequality are the main challenges worldwide. However, overcome these challenges are impossible without local inhabitants’ participation. The objective of this research was to evaluate the watershed management measures ...
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Abstract: land degradation, air pollution, food deficient, poverty as well as inequality are the main challenges worldwide. However, overcome these challenges are impossible without local inhabitants’ participation. The objective of this research was to evaluate the watershed management measures which measured through joint project by Forests, Rangelands and Watershed Organization (FRWM) and Middle East and North Africa Regions Program for Integrated Development (MENARID) in Razin watershed, Kermanshah, Iran during 2013-16. Local inhabitants were interviewed using questionnaire. The results explored that constructed measures comprise the pit- seeding, rain-fed orchard, stony dam, gabion and dyke. However, most of respondents did not agree with biological measures (pit- seeding, rain-fed orchard) due to limitation for their animal grazing, persuading land-use change and enhancing conflicts among them, while rare inhabitants were willing to rain-fed orchard due to their expects on rangeland ownership and loan opportunity. Approximately 85% of local people confirmed that they did not consult or collaborated during watershed management measures, although they had environmental friend ideas. They believed that mechanical measures are impossible solutions in terms of soil conservation, flood control, runoff harvesting and supplemental irrigation. Overall, local communities worried about climate change and its sever negative impacts on agricultural activities and livelihood, thus watershed management and governance should be taken urgent steps overcome or adapting hits of droughts due to their literacy and experience during recent years. It is concluded that local inhabitant's ideas and their participations should be considered as the necessary step to obtain the effective results and sustaining watershed management measures.
Samad Shadfar
Abstract
Gully erosion is a type of water erosion that causes significant sedimentation in watersheds and damages in agricultural lands, rangelands, and infrastructures. This study was conducted to determine the potential of gully erosion by artificial neural network. The Levenberg-Marquardt (LM) ...
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Gully erosion is a type of water erosion that causes significant sedimentation in watersheds and damages in agricultural lands, rangelands, and infrastructures. This study was conducted to determine the potential of gully erosion by artificial neural network. The Levenberg-Marquardt (LM) algorithm and Multi-Layer Perceptron were used employing soil, geology, land use, distance to fault, slope, aspect, distance from roads, distance from drainage, and elevation data as its variables. Results showed that the structure of 1-13-9 with sigmoid activation function in the hidden layer is more suitable for gully erosion potential assessment. Zonation of gully erosion revealed that the watershed area was divided into different classes of different extent, including 70.26% in very low, 1.71% in low, 2.45% in medium, 2.65% in high, and 22.93% in very high potential class. Furthermore, results indicated that slope less than 10%, 50 m distance from the stream, rangeland area, and lithological units of EM and M2 had the greatest impact on the occurrence of gully erosion.
Rahim Kazemi; Samad Shadfar; Reza Bayat
Abstract
Information on the hierarchical importance of the factors influencing on the spatial distribution of springs in a watershed are required for the development of the water quality and quantity management plan. In this regard, we address the integration of GIS and decision support tools, for zoning prone ...
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Information on the hierarchical importance of the factors influencing on the spatial distribution of springs in a watershed are required for the development of the water quality and quantity management plan. In this regard, we address the integration of GIS and decision support tools, for zoning prone areas. In this research to determine hierarchical importance of the elements on the water resources development in Karst regions, first with literature review and field studies, the effective parameters in occurrence of spring were selected. Then thematic layers of these parameters in GIS environment were prepared. Each layer separately crossed with the spatial distribution of spring's layer and priorities of each sub layer with respect to each other in terms of frequency of spring's occurrence were determined. Finally, using the analytic hierarchy process, factors affecting the occurrence of this phenomenon and the weight of each factor was calculated by Expert Choice software. Results showed that the weight of the top layer assigned to the lithology and carbonate substrate alone formed 54% of the weight of this layer. The next layers in order of importance were including the layer of the slope and elevation classes, structural elements, lineaments, limestone contact and drainage layer. Potential map prepared by this method, match 76 percent with the spatial distribution of springs.
Saeed Nabipay Lashkarian; Seyed Ali Asghar Hashemi; Samad Shadfar
Abstract
Erosion and sedimentation are main challenges in Iran, which cause the reduction of soil quality and quantity. Soil conservation and watershed management activities should be implemented to reduce the impact of these phenomena. Therefore, the knowledge of critical area is necessary through the learning ...
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Erosion and sedimentation are main challenges in Iran, which cause the reduction of soil quality and quantity. Soil conservation and watershed management activities should be implemented to reduce the impact of these phenomena. Therefore, the knowledge of critical area is necessary through the learning the amount of sedimentation and erosion. Because of lack of sediment measurement stations in more watershed outlets in Iran and insufficient data, empirical models are proper tools for data layers generation. Factorial Scoring Model (FSM) is one of the experimental models which has been recently developed out of the country. The main objective of this research is to compare sediment yield estimated by FSM model and observed values. So, in order to evaluate the model, nine small dams of 10 years old with no overflows were selected from in Semnan province. For modeling sediment yield, topography, lithology, gully, catchment shape and vegetation cover of related catchments were studied and required data layers were prepared and scoring indexes were given and finally, the calibrated model was presented. Estimated model values were then compared with measured values. Results showed that main model equation does not have sufficient efficiency. Also, results demonstrated that calibrated FSM model has conformity with observed sediment values at 84 percent.
Hamid Reza Peyrowan; Amir Samadi Tabrizi; Samad Shadfar; Ahmad Motamed
Abstract
Marl formations are widespread in Iran. High potential to erodibility of marl formations in watershed basins of Iran cause many problems including loss of soil quality in agricultural and pasture lands and forests, increasing the risk of landslides and mass movements, reducing the quality of ground and ...
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Marl formations are widespread in Iran. High potential to erodibility of marl formations in watershed basins of Iran cause many problems including loss of soil quality in agricultural and pasture lands and forests, increasing the risk of landslides and mass movements, reducing the quality of ground and surface water, sediment load increases entered into the reservoirs, desertification areas due to intensive erosion and watershed management plan failure due to inadequate knowledge of the susceptibility to erosion the formations. The study area, Gatchab and Siahkooh Mountains situated in the northwest of central playa of Iran (Kavir plain). It is located in southwest of the Semnan city with 74 km distance. The widespread of the geological unit in the area is upper red formation with three members M1, M2 and M3. With respect to sedimentology finding on textures of Neogene sediments, they are sandy silt, silt, sandy mud and mud particles. The examination of distribution of various particle size of the sediments have shown that these sediments deposited in shallow water and lagoonal environments with changing of the depth, that changed to high dynamic environments condition of channel rivers. The results of analyses have shown that the percent abundance of lime in these sediments change from 24.28% to 34.98%. Because of the low contents of lime compound and clay particles, it is better to called them salty and gypsiferous siltstone and mudstone instead the marl term for these sediments.
Samad Shadfar; Ali Akbar davoodirad; Hamid Reza Peyrowan
Abstract
Gully erosion is a type of water erosion which causes degradation in both agricultural fields and rangelands as well in arid and semi-arid areas. According the role of soil degradation due to erosion, research objectives were to find out investigation causes gully erosion in Robat Tork Watershed. In ...
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Gully erosion is a type of water erosion which causes degradation in both agricultural fields and rangelands as well in arid and semi-arid areas. According the role of soil degradation due to erosion, research objectives were to find out investigation causes gully erosion in Robat Tork Watershed. In this research three representative gullies were selected in agriculture and rangeland working units. In each working unit, samples taken from nine soil profiles were analyzed for texture, organic matter, gypsum, total lime, pH, EC and SAR. Soil infiltration rate was measured where were drilled profiles in each working unit too, In addition, morphometric characteristics of gullies including length and lateral profiles, top and down width, depth of gully, the cross section, width to depth ratio, the slope of bed, gully length were studied. Results of the study showed that SAR and sodium cation are caused dispersion of soil particles and increasing gully erosion. percentage of clay and silt is 11% and 29% in surface layer representative head cut gully and organic matter is between 0.30% to 1.82% in agriculture unit. In rangeland unit, percentage of clay and sand is 41% and 43% in surface layer representative head cut gully and organic matter is between 0.29% to 0.99%.In rangeland unit, in a specified level, the number of gully is more than agriculture unit. Furthermore, the results showed that TNV in agriculture unit and pH, EC in rangeland unit is more than. In both units depth to wide ratio is more than 1 in every gully. Permeability of soil is 4.25 cm and 3.45 cm in agriculture and rangeland units respectively.
Samad Shadfar; Mojtaba Yamani; Mohammad Namaki
Abstract
One of the hillslope movement processes is land sliding which causes both human loss and economic damages. Factors such as structural and dynamic developed landforms , forests clearing, incorrect technical principals in construction and maintenance of rural and forest roads, lack proper management and ...
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One of the hillslope movement processes is land sliding which causes both human loss and economic damages. Factors such as structural and dynamic developed landforms , forests clearing, incorrect technical principals in construction and maintenance of rural and forest roads, lack proper management and using existing resource causes much damages to rural settlements, construction activities, forest, rangeland, and agriculture lands every year. Landslide Hazard Zonation is the first step for proper land management to overcome these problems. To prepare LHZ, several thematic layers such as lithology, slope, elevation, land use, distance from faults and distance form drainage were digitally prepared. Landslide distribution map of the area was prepared through Arial photos interpretation and also field checks. The thematic layers were integrated using information value, area density and LNRF models in a GIS environment. Finally to validate the results, a sub-basin was selected as a control area and the calculated weights for this sub-basin were applied for the rest of the catchments. The result of this investigation indicates that most of the landslide occurred in pdr, Js lithological units composed of marl, clay and silt layers, slope class 30- 50 and on elevation 2000- 2500 m. Also, most of the instability are on rangeland and occurred in a distance of 0-300 m from drainage network. The research shows that the estimated percentage of high hazard class is 79, 63, and 66 percent for area density, LNRF, and information value models respectively.
Esmaeil Sharifi; Hossein Ali Habibi; Mohammad Namaki; Samad Shadfar
Volume 2, Issue 1 , May 2010, , Pages 1-10
Abstract
Leadership is one of four basic steps in the management process. It involves leading, influencing and motivating group or organization members and or any social structure. Investigation of leadership characteristics in watershed management which is a non-governmental social structure is of important ...
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Leadership is one of four basic steps in the management process. It involves leading, influencing and motivating group or organization members and or any social structure. Investigation of leadership characteristics in watershed management which is a non-governmental social structure is of important consideration. In this research, various theories of leadership along with integrated definition of its obligations were brought under consideration. Furthermore, various methods and styles of leadership were analyzed by exact designing about its network. Thirteen required attitudes for practicing of management were extracted and determined during this research. Nowadays, scientists believe that consultation and intermediation skills are the most important factors in non-government and social organizations since in the various research is known that economic analysis are among the isolated matters for these non-governmental social systems. Importance of getting in contact with minorities and other cultural groups, ability in resolving of wrangling and evaluation of politic conditions, and also distinguishing of social requirements have been recommended as the most important factors for management of such an organizations. In consequence of different adjusting theories and styles of leadership in various conditions of watersheds and their residents, the best of leadership options were introduced in different cases. Finally, considering the exploiting of scientific management in watershed administration, suggestion for training managers with scientific skills in post graduate studies are made for watershed management.
Alireza Habibi; Samad Shadfar; Younes Daghigh
Volume 2, Issue 1 , May 2010, , Pages 18-24
Abstract
Recognition from coverage amount of country present conditions in a watershed is unavoidable necessity for optimal and permanent development and utilization. In this research, we choose Fashand watershed in north-eastern of Hashtgerd city. First have recognized independent variables to predicting country ...
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Recognition from coverage amount of country present conditions in a watershed is unavoidable necessity for optimal and permanent development and utilization. In this research, we choose Fashand watershed in north-eastern of Hashtgerd city. First have recognized independent variables to predicting country power. Then prepared various weight maps as informational layers using field studies and Geographical Information Systems (GIS), and classified and composed them together using coverage index. In next stage, coverage predicting agriculture power map with present country conditions map and calculate correlation matrix. Results showed that predicted area with much week and week talent include intermediate rangelands with 19.47 percent coverage areas with medium talent for agriculture intensity have 0.3 percent stratification. And good and very good predicted areas for agriculture intensity include 39.7 percent, good rangelands 2 percent, poor rangelands 29 percent. Unfortunately 994 Hectares of very good agriculture rascals have specialized to civic areas that shows having no comprehensive programs in this base. Prediction shows that 9259 ha of rascals with 53.17 percent of total areas include very good agriculture lands and medium, week and very week areas include less than 23 percent of total Fashand area. Finally, we suggest that programmers and propagators present a model for each area regard to ecological power of area and present intensities conditions, to have in mind area with optimal utilization and suitable intensity use.
