Determining potential points of pollution in a river catchment using GIS and remote sensing.

Abstract

The quality of surface water in many areas of the world is being deteriorated from both point and non-point sources however this study focuses on factors enhancing surface water pollution from non-point sources which is a necessity to enable implementation of management practices that control and prevent pollution. In this study, the basic factors enhancing pollution of surface water were identified including five factors Land use/land cover, Flow accumulation, slope map, soil infiltration, and distance from streams and their thematic layers were prepared from. some maps and satellite images by the remote sensing techniques, digitized and integrated in the GIS environment using Weighted Index Overlay Analysis (WIOA) method. The weights of different factors were objectively determined during the research. Through this integrated GIS. analysis, potential risk pollution map of the study area was prepared. This work nee-ds to be. verified by further analysis of the potential risk polluting areas and also putting in consideration factors like, soil depth and ground water depth and flow. The output of the overlay in the pollution risk map were verified by looking at the Google Earth imagery and incorporation of USGS overlays (contours) in them and field visits in some cases were done The study revealed that this approach can be used by decision makers as a land use planning tool