Mapping the karstification potential of central Cebu, Philippines using GIS

Abstract Karstification is influenced by numerous factors, such as climate, geomorphology, and anthropogenic processes. Karstified areas are usually faced with numerous karst-related problems such as sinkhole formation, ground subsidence, and groundwater vulnerability. We evaluated the karstification potential of central Cebu, Philippines using Raster Overlay Analysis (ROA) in a geographic information system (GIS) platform. Raster Overlay uses multiple thematic maps which represent the different factors affecting karstification. Thematic factors include precipitation, temperature, vegetation density, elevation, slope, drainage density, lineament density, and geology. These factors were then correlated with the generated karstification potential map using the Cell Statistics tool. ROA reveals that more than 65% of central Cebu has low to moderate karstification potential. Areas with moderate to very high karstification potential coincide with locations of nine known caves. Cell Statistics reveal that the karstification potential map is strongly correlated with precipitation and is least correlated with drainage density. Information on the karstification of an area underlain by highly soluble bedrock is beneficial to effective land use planning and reduction of hazards related to karst degradation and collapse.