A Comparative Analysis of Topsis and Fuzzy- Topsis for Groundwater Potentiality Prediction in Basement Terrain Using Geophysical Data Sets

Abstract

This research combined remote sensing, geology and geophysical methods, fifty five (55) Vertical Electrical Sounding was carried out in the study area for proper groundwater potential investigation. In order to map groundwater potential of the area, eight thematic factors that influence groundwater occurrences and movement such as geophysical data (aquifer transmissivity, hydraulic conductivity, overburden thickness, recharge rate and aquifer resistivity), geologic data (lithology) and remote sensing data (slope and lineament) were ranked based on technique for order of preference by similarity to ideal solution (TOPSIS) and the developed Fuzzy technique for order of preference by similarity to ideal solution (FTOPSIS). The groundwater potential model map was evaluated using the developed FTOPSIS (Fuzzy Technique for Order of Preference by Similarity to Ideal Solution) and conventional TOPSIS. The groundwater potential of the area of study was qualitatively classified into five classes, namely; very high, high, moderate, low, and very low which account for 19%, 21%, 23.5%, 31.5%, and 5% of the total area respectively. The quantitative validated result of the developed GPM map (FTOPSIS) using the Receiver Operating Characteristics (ROC) technique, yielded the result of 0.84 which indicates 84% prediction accuracy while the prediction rate for the TOPSIS based model 0.75 representing 75% prediction accuracy respectively.