Abstract
Modelling the hydrological characteristics of watershed is a method of
understanding behavior and simulating the water balance components of
watershed for planning and development of integrated water resources
management. The soil and water assessment tool (SWAT) physically based
hydrological modelling was used for modelling hydrologic characteristics
of the Hangar watershed. The data used for this study were digital
elevation model (DEM), land use land cover data, soil map,
climatological and hydrological data. The model calibrated and validated
using measured streamflow data of 13 years (1990-2002) and 9 years
(2003-2011) respectively including warm-up period. The SWAT model
performs well for both calibration (R2 = 0.87, NSE = 0.82 and PBIAS =
+1.4) and validation (R2 = 0.89, NSE = 0.88 and PBIAS = +1.2). The
sensitivity analysis, which was carried out using 18 SWAT parameters,
identified the 13 most sensitive parameters controlling the output
variable and with which goodness-of-fit was reached. The analysis
results indicated that the watershed receives around, 9.6%, 59.9%, and
30.5% precipitation during dry, wet and short rainy seasons
respectively. The received precipitation was lost by 9.6 %, 40.5%, and
41.3% in the form of evapotranspiration for each seasons
correspondingly. The surface runoff contribution to the Watershed were
3.8%, and 79.2% during dry and wet seasons respectively, whereas, it
contributes by 17.0% during short rainy seasons.