Abstract:
Floods have caused devastating impacts to the environment and society in Awash River Basin, Ethiopia.
Since flooding events are frequent, this marks the need to develop tools for flood early warning. In this
study, we propose a satellite based flood index to identify the runoff source areas that largely contribute
to extreme runoff production and floods in the basin. Satellite based products used for development of
the flood index are CMORPH (Climate Prediction Center MORPHing technique: 0.25
by 0.25
, daily)
product for calculation of the Standard Precipitation Index (SPI) and a Shuttle Radar Topography Mission
(SRTM) digital elevation model (DEM) for calculation of the Topographic Wetness Index (TWI). Other
satellite products used in this study are for rainfall-runoff modelling to represent rainfall, potential
evapotranspiration, vegetation cover and topography. Results of the study show that assessment of
spatial and temporal rainfall variability by satellite products may well serve in flood early warning.
Preliminary findings on effectiveness of the flood index developed in this study indicate that the index is
well suited for flood early warning. The index combines SPI and TWI, and preliminary results illustrate
the spatial distribution of likely runoff source areas that cause floods in flood prone areas
