Assesement of Groundwater Potential Zones Using Remote Sensing and Gis Technique; a Case Study in Lake Awassa Catchment
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Date
2015-06-06
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Addis Ababa University
Abstract
Groundwater is an important source of potable water. It represents the largest available source of fresh water which lay beneath the ground therefore it has become crucial targeting on identifying groundwater potential zone. Thus an integrated approach was implemented using Geographic Information System (GIS) and Remote Sensing technique for locating promising areas. For groundwater exploration in Lake Awassa catchment, Southern Ethiopia; Satellite image and Toposheets together with field traverses and secondary data have been used as the data source. The thematic layers considered in this study are geology, geomorphology/landform, drainage density, lineament density, rainfall, soil, slope and land-use/land-cover were prepared ;As a result, a ground water potential map (GPM) was generated by modeling these parameters. A multi-criteria analysis following probability weighted approach has been applied for overlay analysis that allows a linear combination of weights of each thematic map with individual capability value. Groundwater potential map results were classified into four classes that describe the potentiality of each cell in the study area for groundwater exploration. These classes are; high, moderate, low and poor groundwater potential area. The high potential zones correspond to lacustrine sediment overlain by alluvium deposit and ignimbrite, and flat to undulating surface which coincide with the low slope and high lineaments density areas. The central part of the study area falls under moderate ground water potential zone while the eastern and southeastern part falls in low to poor ground water potential zone. The resulted groundwater potential zone map validated based on existing water sources well location which were plotted in the Ground water potential zone model and it was clearly shown that the well coordinates were exactly seated with classified zones
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Gis, Ground Water Potential, Lake Awassa Catchment, Landsat, Remote Sensing