Groundwater Potential Zone Identification Using Remote-Sensing-Based/GIS Based Machine and Analytical Hierarchy Process (AHP) for Abbay Watershed, East Africa

Abstract

This paper presents and examines groundwater potential zones with the help of remote sensing and GIS methods for controlling and investigating the geospatial data of each parameter. Groundwater is the most reliable source of fresh water. Because of several conditions such as rapid population growth, urbanization, industrialization and agricultural development, groundwater sources are under severe threat. Climate change plays an important role in the quality and quantity of groundwater potential. In addition, climate change severely affects parameters that influence groundwater recharging. Unreliable exploitation and poor quality of surface water resources tend to increase the decline in groundwater levels. Hence, it is necessary to identify groundwater potential zones that can be used to optimize and monitor groundwater resources. This study was conducted in the Abbay River Basin, where groundwater serves as the main source for agricultural purposes rather than surface water. Seven selected parameters—lineament density, precipitation, geology, drainage density, land use, slope and soil data—were collected, processed, resampled, projected and reclassified for hydrological analysis. For generation of groundwater zones, weightage was calculated using an analytical hierarchy method, reclassified, ranked and overlaid with GIS. The obtained results of weightage were lineament density 37%, precipitation (30%), geology (14%), drainage density (7%), land use land cover (5%), slope (4%) and soil (3%). The consistency ratio estimated for this study was 0.089, which was acceptable for further analysis. Based on the integration of all thematic layers and the generated groundwater potential zones, the map was reclassified into five different classes, namely very good, good, moderate, poor and very poor. The results of this study reveal that 1295.33 km2 of the study area can be considered very poor, 58,913.1 km² is poor, 131,323 km² is moderate, 18,557 km² is good and 311.5 km2 is very good. Any groundwater management project performed in the better regions would offer the greatest value. A similar study would be valuable before planning any water resource development activity, as this would save the expense of comprehensive field investigations.

Keywords: ground water; sensitivity analysis; AHP; GIS; thematic layer; watershed.

DOI: 10.7176/JIEA/14-1-04

Publication date: January 31^st 2024