Remote Sensing and Gis for Groundwater Assessment in Hard Rock Areas. Applications to Water Well Siting in Ghana and Botswana

摘要: Different types of remote sensing data have been evaluated in this thesis with respect to their potential use groundwater assessment hard rock areas. The primary objectives the study (1) evaluate interpretation indicators from high resolution satellite images and aerial photography (2) investigate how interpretations subsequently can be integrated other pertinent data, as a decision support water well siting under difficult hydrogeological conditions. Two areas low-grade metamorphic crystalline rocks Ghana Botswana focus study. has included general field evaluation various optical imagery, special emphasis on lineaments, vegetation, drainage bedrock characteristics. results indicate that top-down approach using multiple sources is beneficial assessment, there are clear advantages digital image preference paper prints. Remote geological topographical maps, borehole geophysical investigations geographical information system (GIS). A number spatial analyses performed identify relationships will prove useful exploration strategies. Correlation studies lineaments capacities not conclusive areas, but demonstrated need for improved lineament descriptors exploration. Lineaments classed by inferred significance has, between several interpreters, shown good reproducibility most significant lineaments. confidence these features being important availability, thereby increased. probabilistic incorporates professional judgment Bayesian framework based different datasets indicating occurrence. clearly show promising, it restricts detailed favourable targets. However, methods assessing fracture zone characteristics needed. Data GIS found an ideal support, time cost effective selection sites or target Errors positional accuracy should, however, carefully considered, yield meaningless analysis GIS. global positioning (GPS) very limiting inaccuracies data.