Estimation of Hydrologic Budget for Gharasou Watershed, Iran

The performance of the SWAT2012 model for estimation of hydrological budget in Gharasou watershed, west of Iran, during 1995 to 2005 was assessed. Digital Elevation Model, hydro-climatological data, soil and land use maps with their properties relevant to the watershed were considered to fulfill the model. A branch program in SWAT-CUP software (SUFI2) program implemented to simulate and validate the model. Both coefficients of determination (R2) and Nash- Sutcliffe coefficient exploited reliable analysis for simulation of the model from 0.37 to 0.87 and 0.39 to 0.73, respectively. Results showed that evapotranspiration was the main source of waste water (49.3%) in the study area. Surface runoff, subsurface flow, groundwater flow, and variation of soil moisture are 14.8, 0.8, 29.9 and 5.2 percent during the study period, respectively. The monthly proportions of different water pathways of input to the river flow take place from intense storms and snow melt during April to the end of May. This study has produced a technique with reliable data base for water budget in Gharasou catchment, which could be successfully developed to manage water resources by many government agencies.