THE WORLD KARST AQUIFER MAPPING PROJECT (WOKAM): A TOOL FOR REGIONAL TO GLOBAL SCALE KARST RESEARCH

A fundamental karst research tool is a map of the specific karst area under study. While easily available at the local level, maps of karst at the regional to global scales have historically been poorly available and of low resolution. Since 1968, at least five maps have been published of karst distribution around the planet. Most were generalizations of mapped carbonate and evaporite outcrops, with the world’s total karst areas estimated as 12-25% of the ice-free land surface. Karst regions contain aquifers and ecosystems that are difficult to manage and highly vulnerable to contamination, especially where they cross international borders. More accurate mapping of their extent is crucial for effective policymaking, research, and public education.

The WOKAM project was established in 2012 to refine earlier maps and establish an international database of karst aquifers. As another advance over previous maps, WOKAM is based on the highly detailed Global Lithological Map (GLiM) and includes selected karst springs, thermal springs, submarine springs, major groundwater pumping sites, caves, and boundaries of confined karst aquifers. WOKAM is a collaborative effort of the International Association of Hydrogeologists’ (IAH) Karst Commission and is partially funded by the IAH.

Data are still being collected and the draft map is under review. Detailed geologic mapping of some areas is lacking, such as in Siberia which preliminary information suggests may contain the world’s largest karst area. WOKAM is created in a GIS platform and updates are planned to continue, even after the initial map is published. The karst hydrogeological community will be invited to contribute to refine the map and its database.