Estimation of Water Balance Components in the Gaza Strip with GIS Based WetSpass Model

This study was initiated to estimate the water balance components in the Gaza Strip for the year 2013 using the WetSpass spatially distributed water balance model. Relevant input data for the model is prepared in the form of digital maps using GIS tools such as rainfall, air temperature, wind speed, potential evapotranspiration, soil, water depth, Topography, slope and land-use. The model produces digital maps of long-term average annual surface runoff, evapotranspiration and groundwater recharge. Results of the model show that 77% of the precipitation in the Gaza Strip is lost through evapotranspiration, 11% becomes surface runoff and 12% recharges the groundwater system. Analysis of the simulated results shows that WetSpass model is good enough to simulate the hydrological water balance components of the study area. Keywords: Water balance, WetSpass model, GI