Abstract:
The objective of this thesis is to quantify groundwater-surface water interaction and to
detect climate change impact on the interaction of the Tana Basin, Upper Abbay Basin
Ethiopia. ArcSwat 2.3.3 model is used for the estimation of surface water balance both
for the observed climate stations and future Regional climate Models (RCM) climate
output scenarios of time periods (2031–2040 and 2091–2000) .From SWAT outputs
developed future climate scenarios have both increasing and decreasing effects in space
and time for surface runoff, but decreasing trend in deep aquifer recharges for all sub
basins.
A three-dimensional transient groundwater flow model ,Modflow 2000,has been used
to quantify groundwater-surface water interaction on those major Rivers
Gumar,Rib,Megech and Gilgel Abay for both the baseline period and future climate
scenarios of the top unconfined aquifer Tana basin .Perturbing groundwater recharge
output from SWAT model for climate scenarios the base period (1990s) and future
climate scenarios (2030s and 2090s).As that of recharge simulated from SWAT model
decreases to the future climates ,groundwater contributing to the streams depicts
reduction . Climates exert larger percentage variation on surface runoff compared to
groundwater-surface water interaction.
