Identification of Groundwater Potential Zone using Multi-Influence Factor Technique (Study Case: Brantas Groundwater Basin, East Java, Indonesia)

Abstract

Brantas Groundwater Basin is the biggest groundwater basin in East Java Province, Indonesia. It is covering 22 regencies/cities which have high water need. Mostly people water need is supplied from groundwater. Identification of Groundwater Potential Zone (GWPZ) is required to ensure sustain groundwater supply for fulfilling that water need. One technique for that is Multi-Influence Factor (MIF). It considers influence factors of groundwater such as rainfall, geology, geomorphology, slope, lineament density, drainage density, soil texture, and land-use/landcover. Raster data obtained from Google Earth Engine (GEE), Aster DEM, and Geological Map of East Java were included as the research data. They had score and were estimated by using MIF technique. GEE and open-sourced GIS were used in computational raster data processing of MIF technique. Identification result of GWPZ showed that Brantas Groundwater Basin consist of zones which are very poor (2% area), poor (24% area), good (47% area), and very good (17% area). The result can assist hydrogeologist and local authorities to formulate further policy of GWPZ management.