GIS-Based Assessment of Groundwater Recharge Areas and Spatial Planning Suitability in West Pasaman Regency - Indonesia

Abstract

The decline in the function of groundwater recharge areas is one of the impacts of uncontrolled land-use change. West Pasaman Regency, a region characterized by high annual rainfall and rapid expansion of cultivated land, faces increasing challenges in maintaining regional hydrological balance. This study aims to assess groundwater recharge conditions and evaluate their suitability with the Regional Spatial Plan (RTRW) of West Pasaman Regency using a Geographic Information System (GIS). The analysis integrates four environmental parameters, namely land cover, soil type, rainfall, and slope, using a scoring and weighting approach based on the Regulation of the Minister of Forestry No. 32 of 2009 combined with GIS overlay analysis. The results classify groundwater recharge conditions into five categories: Good, Natural, Moderately Critical, Critical, and Very Critical, with moderately critical to very critical areas predominantly occurring in cultivated and settlement zones. The suitability analysis further reveals several inconsistencies between groundwater recharge conditions and the existing spatial plan that may reduce groundwater recharge functions. By integrating groundwater recharge assessment with spatial planning evaluation, this study provides a practical GIS-based framework for identifying priority areas for groundwater conservation and supporting sustainable land-use planning.