Remote sensing and GIS for mapping groundwater potential zones

Low success rate of drilling productive wells is a common challenge in hard rock environment. The use of remote sensing with ground information is becoming effective method in improving success rate. In this work thematic layers generated from satellite images, existing maps and ground survey results were integrated to delineate the groundwater potential zones. Lineament, thermal lineament, soil moisture, vegetation anomaly and landuse/landcover factors maps were generated from images and slope, drainage density and lithology were derived from existing maps. The zone of weathering layer is generated from water point inventory and Vertical Electrical Sounding survey interpretation results. Data derived from different sources were processed, analyzed and reclassified to common scale and weighted. Multi-criteria evaluation using pairwise comparison matrix was used for ranking the thematic layers. Then raster based GIS modeling was conducted using Weighted Linear Combination method to generate the groundwater prospect map. The resulting groundwater prospect map revealed large part of the study area has poor groundwater potential which is in good agreement with the field survey result.

Autorentext

Gezahegn Lemecha has graduated with Bsc degree in Geology from Addis Abeba University in 1991. Since then he has worked as field hydrogeologist. In 2oo7 he graduated with MSC degree in Remote Sensing and GIS. This work is part of the long year experience as field hydrogeologist and MSC research result.