ِAli Tavili; S. Motahareh Hosseini; Mohammad Jafari; Ali Golkarian
Abstract
MAXENT model was used to evaluate the probability of Dorema ammoniacum development in rangelands of Southern Khorassan. Presence data of D. ammoniacum was recorded based on field survey and GPS application. Nine environmental information layers were used to model potential habitat of the understudy species. ...
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MAXENT model was used to evaluate the probability of Dorema ammoniacum development in rangelands of Southern Khorassan. Presence data of D. ammoniacum was recorded based on field survey and GPS application. Nine environmental information layers were used to model potential habitat of the understudy species. Relationship between species presence and environmental parameters was determined using maximum entropy. Map of species distribution was achieved. Results showed that the probability of D. ammoniacum is higher in regions with the following environmental characteristics; elevation of 1017-1933 m, average temperature of 13.96 to 15.17 ºC, average precipitation of 112- 131 mm, slope of 0-14% and LST range between -4 to 10 ºC. An AUC of 92 demonstrated that MAXENT is a suitable model for prediction of D. ammoniacum distribution and potential habitat.
mahbube hoseini; Ali Golkarian
Abstract
Resource management governing as one of the most valuable nature resource of watersheds with the involvement of local beneficiary to participatory management of water resources, one of the requirements of the water security program. So we considered social network analysis as an approach to analyzing ...
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Resource management governing as one of the most valuable nature resource of watersheds with the involvement of local beneficiary to participatory management of water resources, one of the requirements of the water security program. So we considered social network analysis as an approach to analyzing the relationship between local stakeholders for sustainable management of water resources. The purpose of this study is study social network of local stakeholders using social network analysis in watershed of Kharve Olya of Neyshabur city. This study has been made based on trust and participant links and using quantitative and mathematical indicators in network macro-level (density, concentration, links reciprocity, transferability of links, the average geodesic distance). The results show that social capital degree based on trust and participant links was strong and stability and balance of network is evaluated at the upper limit that indicates a high level of mutual trust and participant among the local stakeholders. Also the correlation between trust and participant links based on QAP index was 66% and upward average. Results of mean geodesic distance index based on trust and participant link trust indicate trust and participant flow rate is from moderate to high degree. The results can be argued that high levels of social capital and unity among people lead to increase trust and participant flow rate among stakeholders so we can accomplish successful governing of water resources at the less expense and time.
Ali Golkarian; Abbasali Mohammadian; Abolfazl Abdollahi
Abstract
The first condition for control erosion and improve of watershed with critical status, identify and prioritize areas and catchments with a critical situation. At the time of control activities implementation, this action causes, more considered higher priority areas and conservation programs focus on ...
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The first condition for control erosion and improve of watershed with critical status, identify and prioritize areas and catchments with a critical situation. At the time of control activities implementation, this action causes, more considered higher priority areas and conservation programs focus on such areas. The purpose of this research is priorities for watershed management sub basins of Daryan watershed, using similarity to ideal option (TOPSIS) method. First, in this study, six criteria (population, average production, water resources, agricultural land surface, erosion and formation) to prioritize is selection, and then the weight of each criterion using entropy method was determined. Among the criteria studied population and erosion were the highest and lowest weight respectively. The results showed that among the 38 sub-basins studied, sub basin A10, A’11 and B’7_A’12_C’21 because of high-ranking criteria of population, water resources and agriculture have the highest priority and sub basin C6, C9 and C’7 due to the lower these criteria the lowest priority given to the watershed.
Bita Shiravi; Ali Golkarian; Ali Abotalebi pirnaeemi
Abstract
Check dams, are small dams in the watershed. These dams are constructed in susceptible areas to erosion due to reduce of flow velocity and erosion, control of sediment and flood in upstream of reservoir dams. These structures are made using wood, stone and cement, and Gabion. These structures change ...
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Check dams, are small dams in the watershed. These dams are constructed in susceptible areas to erosion due to reduce of flow velocity and erosion, control of sediment and flood in upstream of reservoir dams. These structures are made using wood, stone and cement, and Gabion. These structures change the hydrological response of the watershed by reducing flow velocity, the channel slope and storage of flow.
Analyzed the effects of these dams before making can be deciding on the correct and efficient implementation of the project as well as better management in order to achieve various objectives effectively. Since the constructions of these dams are effective on flood behavior, this research aims to impact of check dams on time of concentration and reduction of flood peak discharge in the Gash watershed. In this research are used from Puls method for flood routing in reservoir and Muskingum method for flood routing in river due to evaluate the impact of dams, and also flood hydrograph with 25 to 100 year return period was simulated the situation before and after construction of dams. The results showed that the proposed check dams are reduced peak of flow between 75 to 97 percent and flood volume from 73 to 98 percent that shows the positive effects of the construction of these dams in reducing the peak of flow and flood volume. In addition, in different return period with increasing peak of flow and flood volume, reservoir role in reducing peak of flood discharge and flood volume will be decreased. Also time of concentration will be increased between 0.26 to 0.98 hours by Construction of check dams.
Ali Golkarian
Abstract
Erosion is one of the important factors in soil degradation and decrease fertility and slope length is one of the most effective factors in land form and amount of erosion. The objective of this study was investigation of spatially variation of sediment concentration in slope length until to receive ...
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Erosion is one of the important factors in soil degradation and decrease fertility and slope length is one of the most effective factors in land form and amount of erosion. The objective of this study was investigation of spatially variation of sediment concentration in slope length until to receive transport capacity. To obtain this goal a hill slope simulator system designed and manufactured. This system include 10 flumes, each has five meter length which after series them become fifty meters. This system can produce cumulative flow via fifty watering can tube which are install on flumes with one meter interval and each flume discharging is 100 cc. Other variables include two type of soil and slope in three level 15, 22.5, 30 percent. Three replications were used for each treatment and totally 18 experiment was done. In each experiment four samples were gathered from end of each flume and concentration was determined. Complete randomized design with factorial arrangement was used for data analyzing. Richard’s function was used for fitting a suitable curve on observed data. Result was shown that effect of soil type on sediment concentration was not significant while slope and slope length effects was significant. Otherwise sediment concentration in the two last flumes was located in same class which is shown that sediment concentration achieved to transport capacity in this slope length. Also results were shown that Richard’s function can simulate trend of concentration variety in slope length.
Ali Golkarian; Davoud Davoudi Moghaddam; Seyed Amir Naghibi; Masoud Eshghizadeh
Abstract
Soil erosion is undoubtedly one of the most important problems in natural areas and has a devastating impact on grassland ecosystems. The present study was conducted to assess the ability of Rangeland Hydrology and Erosion Model for estimating sediment yield on rangeland’s hill slopes in dry regions ...
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Soil erosion is undoubtedly one of the most important problems in natural areas and has a devastating impact on grassland ecosystems. The present study was conducted to assess the ability of Rangeland Hydrology and Erosion Model for estimating sediment yield on rangeland’s hill slopes in dry regions at Shahid Noori paired watershed of Kakhk. RHEM is a mathematical, distribution and physical model that is capable to simulate hydrological and erosional processes with climatic data and hill slope’s characteristics. Measuring of sediment yield performed on 18 erosion plots in both disturbed and undisturbed rangeland conditions. In order to implement the model, the parameters of climate, soil texture, slope length, slope steepness, canopy cover and ground cover were measured and entered into the model to estimate amount of runoff and sediment yield in each year. The analysis showed no significant difference between observed and estimated values at 5% level in both all erosion plots and the average of measured values of all three different aspects. The results indicate that the model is capable to determine the quantity effects of rangeland conservation practices in hydrological and soil erosion processes. Overall, the present study suggested good potential for application of the model in the same rangelands of dry regions.