dc.description.abstract |
Floods are common to many parts of Ethiopia causing a lot of losses to human lives as
well as damage to property. This thesis was conducted to know the extent of flood
inundation area for Azuari River. Different models used for this study such as, hydraulic
model HEC-RAS, hydrological model HEC-HMS with integration of ArcGIS, HECGeoHMS and Ras Mapper tools. Primary data, surveyed river cross section and
secondary data‟s such as rainfall, stream flow, DEM, Land use / land cover and Soil type
data‟s collected and used for the study. Totally around 30 years of observed flow data 20
years (1985-2004) for calibration and 10 years (2005-2014) for validation used. After the
analysis of the data it was find that HEC-HMS calibration and validation result was good
and the performance of the model. This performance is checked with coefficient of
determination, Nash-Sutcliffe Efficiency, Root mean square error(RSR) and present of
bias (PBIAS) with good result of 0.73,0.73,0.49 and -1.5% for calibration, 0.81, 0.8, 0.45
and-1.3% for validation respectively. The result of hydrologic model by HEC-HMS
shows a flow value of 52.80m
3
/s, 121.00 m
3
/s,181.00m
3
/s and 223.00m
3
/s for return
periods of 2, 10, 50 and 100 year respectively. Due to the unavailability of observed
water level and rating curves in the study area the HEC-RAS model calibration and
validation result compared information gathered from elderly person. These flooded areas
along the side of the Azuari River are 0. 92 km
2
, 0.72km
2
, 0.59km
2
and 0.42km
2
for 100,
50, 10 and 2years return periods, respectively. Therefore in order to mitigate this damage
structural and nonstructural measures recommended depending upon the severe of
damage at each station.
Key words: ArcGIS, HEC-HMS, HEC-RAS, TIN, DEM, Flood map |
en_US |