GIS and Remote Sensing Application for Groundwater Potential Zone Delineation: the Case of Nili River Catchment of Tekeze River Basin Amhara Region Ethiopia.
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Date
2020-10
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Addis Ababa University
Abstract
Groundwater is treasured and very important natural resource globally. It is also the
most essential for the development of a country. However, groundwater potential zone
mapping still remained uncertain due to the challenge nature of groundwater and also
less studied. Therefore, this research aimed at delineating the groundwater potential
zone of Nili river catchment by using the integration of Geographic Information System
(GIS) techniques Hence, in this estimation seven controlling factors are used as thematic
layer which, were derived from 30m*30m resolution Digital Elevation Model (DEM)
data, and exiting map of geology, geomorphology, slope, drainage density and land
use/land cover, rainfall, and soil texture. The groundwater potential evaluation of Nili
river catchment utilized the above factors as an input data using weighted overlay
analysis and Analytical Hierarchy Processes (AHP) methods. In this analysis each
thematic layers were weighted, calculated and compared with different literature values
of similar researches at different localities. After weighted average calculation of each
thematic layer, relative importance was assigned values according to AHP scale.The
analysis showed that groundwater potential of the study area ranges from moderate
(31.66%) to very poor (16.13%) with intermediate potentials rated as good (27.59%) and
poor (24.62%). The analyses revealed that most important influencing factors of the
groundwater potential zones of the study area (Nili river catchment) are geology,
geomorphology, land use land cover and slope as compared to the other controlling
parameters such as rainfall, drainage density and soil texture. The model result also
indicated that good groundwater potential is associated with low slope, flood plains, crop
lands, low drainage densities and high rainfall areas. In converse, poor groundwater
potentials are associated with steep slopes mainly to mountains areas, bare lands, high
drainage densities and low rainfall areas. Therefore, this research shows vigorous
technique using GIS is economically affordable, technically competent and valuable for
delineating groundwater potential zones. It is also recommended that the Nili river
catchment needs geophysical investigations and further wells drilled in the catchment to
get supplementary subsurface formation.
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Keywords
Groundwater potential, GIS, Remote Sensing ,Blesa, Nili River, AHP