Assessing the accuracy of GIS-based elementary multi criteria decision analysis as a spatial prediction tool – A case of predicting potential zones of sustainable groundwater resources

Summary Inappropriate handling/integration of data from various sources is a problem that can make any spatial prediction tasking and inaccurate. Attempt was made in this study to offer solution to this problem by exploring the capability of GIS-based elementary MCDA as a spatial prediction tool. In order to achieve the set objectives, spatial prediction of potential zones of sustainable groundwater resources in a given study area was used as a case study. A total of five set of criteria/factors believed to be influencing groundwater storage potential in the area were selected. Each criterion/factor was assigned appropriate weight based on Saaty’s 9 point scale and the weights were normalized through the analytic hierarchy process (AHP). The process was integrated in the GIS environment to produce the groundwater potential prediction map for the area. The effect of coherence of criteria on the efficiency of MCDA as a prediction tool was also examined. The prediction map produced was found to be 81.25% accurate. The results of the examination of the effect of coherence of criteria revealed that the ability of the method to produce accurate prediction is dependent on the exhaustiveness of the set of criteria used. It was established in the study that the GIS-based elementary MCDA technique is capable of producing accurate and reliable prediction particularly if the set of criteria use for the prediction is coherent.