Flood Hazard Assessment Using Gis in Bacho Plain, Upper Awash Valley, Southwest of Addis Ababa
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Date
2007-07
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Addis Ababa Universty
Abstract
Gis In Bacho Plain Flood hazard mapping is used to determine the areas susceptible to flooding when
discharge of a stream exceeds the bank-full stage. Using historical data on river stages
and discharge of previous floods, along with topographic data, maps can be
constructed to show areas expected to be covered with flood waters for various
discharges or stages. An effort was made in this study to identify flood hazard areas in
Bacho Plain using GIS technology. Bacho Plain is an agricultural potential area in the
western extreme of Upper Awash Valley. The area is drained by a number of large
perennial rivers which are tributaries of the largest Awash River. The study area is
spread within an extent of 1,539 sq km. Bacho Plain experienced flooding problem of
different level (very low to moderate) almost every year and major floods every five
years for the last two decades. These destructive floods were detrimental to Bacho
Plain’s vulnerable social and economic development due to loss of lives and
destruction to properties. Settlement areas and agricultural fields are situated along the
river banks, which are severally vulnerable to flooding. The main objective of the
study was to develop landuse zonation map of Bacho Plain area, and to identify the
areas vulnerable to flood. Accordingly classified flood hazard map was developed
using GIS and the landuse pattern was identified within the hazard areas. Flood
hazard map was classified into five categories very high, high, Moderate, Low and
very low. The weighted overlay analyses also showed that most of the cultivated
lands, settlements, swampy land areas are in high to very high risk while the
remaining are very low to low risk areas
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Gis in Bacho Plain