Mohammad Golshan; Abazar Esmaili; ali afzali; Afshin Jahanshahi
Abstract
Simulation with using of computer models are developing very fast and these models are essential tools for understanding of man from the watershed and hydrological processes. In this study IHACRES and HEC-HMS rainfall runoff models was used for simulation of four flood hydrographs in Kasilian watershed ...
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Simulation with using of computer models are developing very fast and these models are essential tools for understanding of man from the watershed and hydrological processes. In this study IHACRES and HEC-HMS rainfall runoff models was used for simulation of four flood hydrographs in Kasilian watershed with area 67.8 square kilometers in Mazandaran province. To prepare the Requirements maps for running HEC-HMS model was used HEC-GeoHMS extension. Hyetograph data with 15 minutes time step and its related hydrograph was entered to two models based on 1 hour time step. Then simulation of the flood hydrograph was done based on 15 minutes time step. CP and RE% statistical coefficients was used for evaluation of models performance. Values of this coefficients using the HEC-HMS model for flood 26 November 1994 was calculated 0.72 and 118.26 respectively and for flood 6 October 1996, 0.89 and -24.63 respectively and using the implementation of IHACRES model these coefficients in the first flood was calculated 0.63 and 152.4 respectively and in the second flood 0.79 and -35.6 respectively. The results showed that both use models have acceptable performance for simulation of flood hydrograph in this area and HEC-HMS model has better performance in compared with IHACRES model.
Afshin Jahanshahi; Alireza Moghaddamnia; Hasan Khosravi
Abstract
To assessment and preparation of desertification mapping, much research has been conducted ever within and outside the country that has led to numerous regional models. To provide a regional model and quantitative assessment of current state of desertification, ShahrBabak plain with an area of 4112 square ...
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To assessment and preparation of desertification mapping, much research has been conducted ever within and outside the country that has led to numerous regional models. To provide a regional model and quantitative assessment of current state of desertification, ShahrBabak plain with an area of 4112 square kilometers (Km2) located in the Northwest of Kerman province were considered. In this study, to assess the severity of desertification using thirteen indices that five of them based on groundwater and include: electrical conductivity (EC), sodium absorption ratio (SAR), chloride (Cl), drop of groundwater and water table depth and three of them based on climate data and included: annual rainfall, Transeau drought index, drought index and also three of them based on vegetation and included: Conditions, exploitation and restoration of vegetation, water erosion and irrigation methods in format of desertification Iranian model IMDPA to investigation and determine the class of desertification intensity were done in each of work units. The final score of each of work units and then total area were determined using Geometric average from any of the mentioned indices. Finally the current status of desertification intensity classes were estimated in low, medium, high and very high classes. The results indicated that in the regional proposed model, the study area with respect to intensity of desertification is placed in about 61351 ha (14.92 %) in low class and about 138575 ha (33.7%) in medium class, about 117685 ha (28.62 %) in high class and about 93589 ha (22.76 %) in very high class. Also the weight average of quantitative value estimated 2.06 in total area that it indicated the medium desertification class in the total area.
