Frequency Ratio Model for Mapping Groundwater Potential Zones Using GIS and Remote Sensing; Medjerda Watershed Tunisia

Abstract

Groundwater potential mapping and its sustainable development are an important aspect in the Lower Valley of Medjerda (LVM) river sub-basin due to increased water demand for irrigation and domestic use. The main goal of this study is to investigate the application of the probabilistic-based frequency ratio (FR) model in groundwater potential mapping at LVM river in Tunisia using GIS. This study includes the analysis of the spatial relationships between Transmissivity and various hydrological conditioning factors such as elevation, slope, curvature, river, lineament, geology, soil, rainfall, and land use. Eighteen groundwater-related factors were collected and extracted from topographic data, geological data, satellite imagery, and published maps. About 60 groundwater data of transmissivity were randomly split into a training dataset, 70% was used for training the model and the remaining 30% for validation purposes. Finally, the FR coefficients of the hydrological factors were used to generate the groundwater potential map. It was classified into five zones as very high, high, moderate, low, and very low. This information could be used by water decision makers as a guide for groundwater exploration and assessment in the LVM River.