Identification Of Groundwater Potential Zones Using GIS And Remote Sensing Techniques:a Case Of Adama Watershed, Oromia Region, Ethiopia.

Abstract

Groundwater Is Occurring Within Different Hydrogeology Environment, Geologic Formations And Topographic Settings Are The Factors That Mainly Control The Groundwater Distribution And Development For Different Purposes. A Systematic Evaluation Of Groundwater Is Essential For The Proper Utilization And Management Of This Precious Natural Resource. Integrated Gis(Geographic Information System) And Remote Sensing Are Efficient Techniques In Groundwater Studies; In Facilitate Better Data Analysis And Their Interpretations Of Groundwater Potential Controlling Parameters. In The Present Study, An Attempt Has Been Made To Delineate And Classify Possible Groundwater Potential Zones In The Adama Watershed Of The Ethiopian Rift Escarpment, Found In Oromia Using Integrated Remote Sensing And Gis Techniques. The Thematic Layers Considered In This Study Are Geology, Geomorphology, Drainage Density, Lineament Density, Rainfall, Soil Types, Slope And Landuse/Cover. Further, The Weights Have Been Assigned According To Their Relative Importance In Groundwater Occurrence And The Corresponding Normalized Weights Were Obtained Based On The Saaty's Analytical Hierarchy Process. These Weights Were Applied To Obtain A Unified Weight Map Containing Due Weights Of All Input Variables. The Thematic Layers Were Finally Integrated Using Arcgis And Idris Software To Produce A Groundwater Potential Zone Map Of The Study Area. Thus, Five Different Groundwater Potential Zones Were Identified. In This Study Area, 47.94% Moderate, 33.51%High, 16.73% Low, 1.23% Very Low And 0.59% Very High Groundwater Potential Zones Have Been Identified. The Resulted Groundwater Potential Zoning Map Validated By Using 55Borehole Data. Interestingly Out Of 55 Boreholes 35 Falls On The High, 20 Boreholes Are Overlaid Properly On Moderate Class Of Groundwater Potential Zone. Moreover No Boreholes Were Found Under Low Groundwater Potential Zones Which Reflects The Accuracy Of Results. Finally, It Is Concluded That The Integrated Gis And Remote Sensing Techniques Are Very Efficient And Useful For The Identification Of Groundwater Potential Zones.