APPLICATION OF HYDROLOGICAL MODELS IN A SMALL AGRICULTURAL CATCHMENT FOR WATER MANAGEMENT: CASE STUDY ON WADI EL-RAML WATERSHED-NORTH WESTERN COAST OF EGYPT

Abstract

North Western Coast of Egypt as a semi-arid region suffers from lack of rainfall most of the year except during rainfall events during the winter season which may even culminate with flash floods that causes acceleration of soil erosion and water losses resulting in degradation of the cultivation lands and consequently the agri-food productivity. This region Suffer lack of water reservoirs and terraces construction. Hydrological models are very useful tools for simulating the effect of natural processes and management practices on soil and water resources. Hence, the aim of study is calibrating and validating hydrological models KINEROS2(K2), ARCSWAT, to select the appropriate model and applying it to establish water and Soil conservation strategies such as terraces construction and building reservoirs. A yearly data set was used consisting of weather data, water content measurements and Gerlesh trough technique. Satellite image Digital elevation model (DEM), Land Cover classifications and soil map were used as layers input in models. The Nash–Sutcliffe coefficient (NSE) and coefficient of determination (R²) were used to evaluate model’s performance. The results reveal that the K2 are better than ARCSWAT, with acceptable NSE and R2 values, where the NSE, R2 were 0.86, 0.84 fork 2 and NSE, R2 were 0.55, 0.47 for ARCSWAT respectively. The K2 model was applied in sub-catchment where the estimated result of surface runoff was ranged from 21.92 to 169.695 m 3 ha-1 year-1. Hence, it is recommended that a reservoir can be constructed inside field approximately about 200 m3 ha-1 y-1 for using as Supplementary irrigation during dry period and the result indicated to areas with a high risk of soil loss that ranged from 38.88 to 3,860 kg. ha-1. year-1 .