Groundwater recharge assessment and hydrometeorological scenario in the
Fetam catchment Upper Blue Nile Basin, Ethiopia.
Abstract
Groundwater serves as a vital freshwater source for communities in
Ethiopia, particularly in regions like the Fetam River Catchment within
the Upper Blue Nile Basin, where reliance on rainfall recharge is
significant. However, the uneven distribution of rainfall influenced the
distribution of groundwater. The variability of such factors like
altitude and land use practices presents challenges for sustainable
groundwater management. This study aims to quantify groundwater recharge
rates within the catchment, and assess the land use practices affecting
recharge, and determine average annual meteorological conditions. Seven
years daily meteorological data, including temperature, humidity,
sunshine hours, wind speed, and precipitation were analyzed.
Additionally, satellite imagery was utilized to understand land use land
cover distribution, with the help of field investigation the area is
dominated by cultivated land, grass land bult up, forested and bar
lands. Three established methods like chloride mass balance, water
balance, and water level fluctuation provides 114.5,165 238 mm/year. The
mean annual precipitation over a period of seven years is 1727.2mm/yr
and its average temperature varies from 10.4 to 29.6C°. The mean
recharge rate calculated across all three methods was found to be
172.5mm/yr slightly lower than Ethiopia’s national average of 200 mm/yr.
The dominant land use/cover types identified within the catchment
include agricultural fields, grasslands, forests, developed areas, and
bare land. Notably, water level fluctuation yielded higher recharge
estimates compared to the other methods. Considering the specific
physiographic characteristics of the region, the average value derived
from all three recharge estimation methods offers the most accurate
representation.