Evaluation of Surface Water Resources Using Weap Model (Case Study- Qaraso Basin)

Abstract

This paper provides a method that by using hyologic models determines risk and flood prone zones into the basin and also determines flooding intensity at each sub-basin. First, the basin in the geographic information system (GIS) using Arc Hyo amendment were divided into 14 sub-basins and then the physical characteristics of the basin and sub-basin using ArcHyo entirely were determined by climate and land use and using WEAP model which required simulation of hyological catchments and the total for each sub-basin have been done. Resulted calculations from model run indicate that the contribution level of the small and large sub-basins in the flood basin outlet does not depend on sub-basin discharge quantity and sub-basins with more di charge do not necessarily have more contribution in the outlet discharge. In other words, sub-basins have shown a kind of non-linear behavior. Also, this paper also examines quantitative comparison of peak discharge changes of the basin outlet per watershed, average slope changes, stream, Runoff Resistance Factor (R. R. F) in each of sub-basins, take action to identify most important effective factors on watershed flooding and also critical sub-basin. For this purpose, each of desired facto rs in specific range separately changed at each of sub-basins and amount of this change obtained in the whole basin outlet discharge. In this regard, among sub-basins the sub-basin A9 has the most critical condition regarding effect on the basin outlet flood.