Application of the APLIS Method for Groundwater Vulnerability Assessment in Rote Island Karst Areas

Abstract

The karst area on Rote Island dominates more than 60% of the Island. The land surface conditions in karst areas are generally dry, while below the subsurface is the potential for abundant water resources. This study aims to assess groundwater vulnerability using the APLIS (Altitude, Pendiete/Slope, Lithology, Infiltration, and Soils) method that will integrate with Geographic Information System (GIS) technique. The parameters used are elevation, slope, lithology, infiltration zone, and soil type. Slope and elevation are obtained from DEM maps, the soil is obtained from soil type maps, while lithology and infiltration zone are obtained from geological maps. The lithology and the infiltration zone in APLIS method analysis have a high role in determining the level of groundwater vulnerability. The groundwater vulnerability in Rote Island was divided into four classes: Very low in the Northeast, low in the South, moderate in the East and North, and high in the East and West part of the Island. It explains that a high level of groundwater vulnerability in Rote Island needs to be used as a groundwater protection zone.