Abstract
Abstract
The karst landform holds considerable water resource potential and is known for its underground rivers. On the other hand, the high porosity carbonate rocks on this landform cause the decrease of the natural protection function against groundwater pollution. Hence, the analysis of groundwater vulnerability in the karst area is prominent before making the spatial planning regulation. This recent study aimed to analyze the groundwater vulnerability in the karst area located in a part of Umbulrejo Village, Yogyakarta, Indonesia, and proposed action in groundwater protection. The method used in this research was based on the COP method. The data acquisition was conducted by survey method both for primary and secondary data. The COP (Concentration of flow, overlaying layers, and precipitation) analysis was supported by ArcGis software. The analysis of groundwater vulnerability showed that there were two vulnerability classes, i.e., very high (48.6%) and high (51.4%). These results were influenced mainly by the close distance of the recharge area to swallow holes and the lithology type (karst), which contributed to a very high value in reducing protection against groundwater. A proposed action to support groundwater protection is regulating the land utilization in the area of the settlements.