FLOOD HAZARD ASSESSMENT AND ITS IMPACTS ON PEOPLE LIVING DOWNSTREAM BY USING GIS (CASE OF BARO AKOBO RIVER, JEKOW DISTRICT, GAMBELLA, ETHIOPIA)

Abstract

Flood is one among major problems faced in the Jekow district as it has a devastating effects on households, crops damage, loss of livestock and destruction of other properties. Naturally, flood is a potentially damaging physical event, phenomenon or human properties, cause the loss of life or injury, property damage, social and economic disruption, or environmental degradation. The recent flood impact has displaced many people in the district. The purpose of this study is to assess the flood hazard areas and its impacts on the people living downstream of the Baro river in Jekow district by using Geographic Information System (GIS) tool. From this study, GIS tools of this study used to determine the areas affected by floods due to the high water level in a river caused by the heavy rainfall in the Ethiopia highland. In addition to this, Meteorological data such as temperature data and rainfall data obtained from National Meteorological Service Agency and the digital elevation model (DEM) of the catchment area extracted from the country Digital Elevation Model. Furthermore, frequent field observation also used together with the Global Positioning System readings to generate primary information such as the Jekow river coordinates. Software that have been used in this study is the Arc Hydro 10 software that works as extension on ArcGIS 10.4.1. It has been used for the delineation of the watershed, flood factors generation such as elevation, slope, soil types, land use/cover, rainfall and drainage density maps for the development of the flood hazard map and Multi Criteria Decision Making (MCDM) called Analytical Hierarchy Process (AHP) has been also used for weighting coefficient calculation for the overlay of flood hazard map. Microsoft Excel used for some constructive tables. The study finding shows that, many parts of the district occupied by flood hazard but the areas which are the most suffering (very high) flood areas located in the south west part of the district. The most suffering areas identified as, Mading, Banyrial and Kalkich kebeles. In addition to this, the study finding also found that, the main causes of the flood hazard in the district is the overflow of the Baro river that caused by the heavy rainfall from the Ethiopia’s highland. Moreover, the most flood affected areas identified and its causes are known and the possible mitigation measures are not taken seriously for the control of the flood hazard. Overall, the lives of individuals living in flood-affected areas are at high risk due to a variety of causes, including the deterioration of the flood-prone area's food security status. The District Flood Task Force (Committee) should take their given responsibility seriously and actively.