Study of Groundwater Vulnerability to Contamination in Part of the Klaten District Area, Central Java-Indonesia

Department of Environmental Geography, Faculty of Geography, Universitas Gadjah Mada, 55281 the Special Region of Yogyakarta, Indonesia

^* Corresponding author: mwiwik@ugm.ac.id

Abstract

Water demands and risks of groundwater pollution in the Klaten District consistently increase as the human population grows over the years. This study aimed to examine the intrinsic and specific groundwater vulnerability levels (low, moderate, high) and analyze the spatial distribution and degree of contribution of the parameters to the vulnerability in some parts of the district area. The data included depth to the water table (measured directly at selected wells), rainfall records in 2009–2019, land-use maps (RBI), 30m DEM (SRTM), geological maps and geoelectric data. Groundwater vulnerability was analyzed with the Susceptibility Index by overlaying five parameters, which according to the results varied across the district: shallow to deep groundwater, aquifers that were composed of sandstone, sand and gravels and rock materials in between, topography of <2%and 2–6% and diverse land-use types from agricultural fields to built-up lands. Most of the research area had moderate intrinsic and specific vulnerability (43.93% and 50.53%), followed by high (38.24% and 46.43%) and low (17.83% and 3.04%). Also, depth to the water table and land use are the most influencing parameters. The results of this study are expected to provide a reference for the government to consider factoring in priority areas based on groundwater vulnerability levels in formulating the district’s spatial plan.