The Impact of Climate Change on Water Resources in Penjwen District by Using Water Balance Model (WaSim)

Abstract

Using water balance model to assess the impact of climate change on water resources has increased, due to the reduction of water resources in arid and semi-arid regions. Theresearch tries to explore the impact of precipitation amount on water resources according to soil types and natural vegetation cover in Penjwen Distric. WaSim model is used to assess the impact of soil types and natural vegetation cover on water resources. Results were different depending on soil types and vegetation cover scenarios. The total of precipitation in 2005-2006 was 1267.5 mm (wet year), from this amount, 13.2% turn into overland flow, 45.4% recharge and 41.1% evaporate in loamy to clay scenario, on the other hand in silty clay to clay scenario, 35.8% turn into overland flow, 25.6 recharge and 38.6 evaporate. In the same year, in forest scenario, 8.7% turn into overland flow, 31.3% recharge and 60% evaporate, however, in grass scenario 30.4% turn into overland flow, 45.7% recharge and 23.9% evaporate. The Results were changed radically due to reduction in precipitation that was decreased to 739.1 mm in 2007-2008 (drought year). This reduction in precipitation led to an increase in evaporation rate and a reduction in overland flow and recharge rates under soil types and vegetation cover scenarios.