YonasDejenne, Wondwosen2018-07-262023-11-112018-07-262023-11-112005http://etd.aau.edu.et/handle/12345678/10119Flood occurs repeatedly in Ethiopia and cause tremendous losses in terms of property and life, particularly in the lowland areas. The majority of flood disasters’ victims are poor people living in nearby stretch of floodplain. Therefore, the study was carried out to perform floodplain analysis and risk assessment of Fogera and near by areas. This research involves application of 2D Hydrodynamic Modeling System with Geographic Information Systems (GIS) to develop a regional model for floodplain determination and representation. The study describes the Velocity mangitude ,innudation depth in the area for different flow conditions derived from the historical flow data of the Gumera River. Flood frequency analysis is used for prediction of peak flow for daily time series data and Gumbel and Log pearson Type III is used and Gumbel Distrubution is adopted with( R2 =0.994) and peak flow of the River for return periods of 2,5, 10, 25,50 and 100 years. boundary condition for upstream and downstream were defined. Similarly, flood discharges for different return periods were also inputted as inlet boundary and steady flow analysis was done for the results. The result of Gumbel Distrubution shows a flow value of 233m3/s,281 m3/s,312m3/s,352m3/s,382 m3/s,and 411 m3/s for return periods of 2,5, 10,25, 50 and 100yr respectively. Detailed topographic maps collected from various utility organizations and CCHE2D hydrodynamic models were used for simulations. Model results were evaluated for six different scenarios varying return period 2,5, 10,25,50 and 100yr. Finally, flood map was created. Based on the study the following conclusions were drawn: to represent river flood modelling , we need Good mesh generated based on bathzemeteric data high resolution inculding both river geometry as well as flood plain is very important to get meanigful innduation depth and velocity mangitude map on flood plain. Key words: CCHE2D, GIS, DEM, Flood MapenCCHE2DGISDEMFlood MapThesis