ASSESSMENT OF THE USE OF REMOTELY SENSED RAINFALL PRODUCTS FOR RUNOFF SIMULATION IN THE UPPER BLUE NILE BASIN OF ETHIOPIA

Abstract

The successful application of hydrological models                               
model verification [3], and more generally, it
improves the understanding on the hydrologic
cycle. Nowadays, remote sensing imagery acquired
and processed in real time can provide near-realtime
rainfall at relevant spatio-temporal scales (tens
of kilometers and sub-daily) [2], [4], [5], [6].
Remote sensing has increasingly become a viable
data source to supplement the conventional
hydrological rainfall-runoff simulation, particularly
for inaccessible regions or complex terrains and in
areas where there are no rainfall and stream flow
gauging stations [5], [6].
depends not only on the model structure and
spatial and temporal scale, but also on the
accuracy of the rainfall as a main input. In many
developing countries like Ethiopia, the rainfall
observation network is relatively sparse. In recent
years, several techniques have been developed for
estimating rainfall using satellite data. The Climate
Prediction Center Morphing Method (CMORPH) is
one of them and it uses motion vectors derived from
half-hourly interval geostationary satellite infrared
imagery to propagate the relatively high quality
precipitation estimates derived from passive
microwave data.
The main objective of this research is to compare
the performance of SWAT model using rainfall
input data from remotely sensed and ground
measured data for Gilgel abbay catchment. Based
on the results obtained, it can be said that SWAT
model yields good results for the satellite rainfall
input data when compared to in situ rainfall input
data. Thus, CMORPH rainfall products can
possibly be used for the un-gauged catchment in
the Upper Blue Nile Basin. It is recommended to
test the CMORPH rainfall product over other
catchments with relatively dense in situ data in the
Upper Blue Nile Basin with the same CMORPH
and finer spatial resolutions products.