Browsing by Author "Teshome, Tsedey"
Item Regionalization of flow duration curve for Abbay Basin using GIS technique(Addis Ababa Universty, 2007-02) Teshome, Tsedey; Hailu, Zelalem (PhD)Water resource development planning is usually referred as the process to define how to utilize the available water resource to meet the desired objectives. In order to compensate for the scarcity of data for the available water resource, regionalization is found to be one of the best methods of transferring information from the gauged station to ungaged sites. The purpose of this paper is to develop regionalized Flow Duration Curve for Abbay Basin. Based on similarity of standardized rainfall patterns eight regions were identified and Flow Duration Curves of each region are developed. For the development of reliable flow duration curve, daily flow distribution from the mean monthly stream flow is derived. Flow Duration Curve based on the estimated daily flow is developed and an equation for each region is determined. The regional equations were developed using regression analysis. These equations relate discharges of 70 and 80 percent of exceedance for ungauged watershed in the basin, or for short record length stations and catchment characteristics. Estimation of low flow for ungaged sites (below 50% of exeedance) can be obtained using regional regression method and subsequently Flow Duration Curve for each regions. For the evaluation of hydropower potential sites requires knowledge of the time availability of flow at a certain point in a river as described in Flow Duration Curve. It is also useful in other hydrologic investigations where knowing the average time availability of flow is required, such as for irrigation projects and others.