FAULT DETECTION USING PALSAR-1/2 IMAGE DATA FOR GROUNDWATER ANALYSIS IN CENTRAL AND SOUTHWEST OF DJIBOUTI

Abstract

Fault mapping is done to observe the possibility of fault-driven groundwater flow into the fault systems. Fault detection analysis on PALSAR-1/2 data has been implemented through a series of adaptive and gradient filters to derive a Relief Image. This method was applied to delineate good-resolution faults distribution and to revise faults mapping derived from existing geology maps over Djibouti. Study areas are located in the central and southwest of Djibouti, where faults exist because of continental plate movements, contact of geological formation, and tectonics activities. Results show that the processed Relief Image could delineate the fault lines and remove artifacts from PALSAR-1/2 data. Furthermore, the Geology Scoring Index was introduced in this study to analyze the correlation of groundwater data with the geology setting of borehole sites such as geological formation, fault system from Relief Image, distance to rivershed, type of aquifer, etc. It is shown that the occurrence of fault systems possibly increases the groundwater volume of boreholes in study areas. The proposed study is useful to locate the potential area for groundwater resources in Djibouti.