Flood Hazard And Risk Mapping Using Multicriteria Evaluation And Geospatial Technology: A Case Of Jimma Town Oromia Region, Ethiopia

Abstract

Floods Are One Of The World's Most Common And Devastating Natural Disasters, Claiming Lives And Causing Severe Economic Damage Throughout The World. The Flooding Behavior Has Been Changed Due To How Humans Are Using The Existing Land. Inadequate Drainage Systems And Different Activities Including Deforestation Are Increasing The Magnitude Of The Flood. Jimma Town Is One Of The Floods Affected Areas In The Oromia Region, Especially Areas Around The River. Locally, Jimma City Is Drained By Two Perennial Rivers, Namely Awetu And Kito, Which Will Be Combined Near Dedo Bridge Located Towards The Southwest Tip Of The City And Pass Through Boye Swamp Before They Join The Gilgel Gibe River. Awitu River Is One Of The Main Causes Of The Previous Flood Hazard In The Study Area. Due To The Quick Increment Of The Population, Individuals Are Misusing The Normal Vegetation For Different Purposes, Which Has Lead To Deforestation And Vulnerability To Different Natural Hazards Including Floods. Thus, To Manage Such A Problem, A Detailed Understanding Of Hazard Identification Or Hazard-Prone Area Delineation Is Very Crucial. Therefore, This Study Was Carried Out To Prepare The Flood Hazard And Flood Risk Mapping In Jimma Town Using The Multi-Criteria Evaluation Technique And Geospatial Technologies. Eight Flood Causative Factors Including Rainfall, Drainage Density, Slope, Elevation, Soil Type, Topographic Wetness Index, Distance From The River Were Developed In The Gis Environment And Land Use Land Cover In Remote Sensing Environment Using Erdas Imagine Software. Then, The Weighted Overlay Mce Technique Was Used To Produce A Flood Hazard Map Depending On The Analytical Hierarchy Process (Ahp) Pairwise Comparison Of Eigenvector Value. Idris Software Was Used To Compute The Eigenvector To Derive The Weight Of Each Factor. To Prepare A Flood Risk Map Of The Study Area, Flood Hazard Map, Population Density, And Land Use Land Cover Layer Were Overlaid. The Findings Of The Study Revealed That 6.81% And 28.11% Of The Town Is Under Respectively Very High To High Flood Hazard Zone. Therefore, The Study Will Help The Concerned Authorities To Formulate Their Development Strategies According To The Available Flood Hazard In The Area.