A Statistical Approach to Karst Collapse Hazard Analysis in Missouri

Over 170 karst collapses were documented in reports by the Missouri Department of Natural Resources between 1968 and 2007. Several collapses occurred in populated areas and several resulted in loss of property. Historically, several sewage lagoons in Missouri have failed due to karst collapse resulting in considerable groundwater contamination and leading to the development of a method for evaluating the potential for karst collapse. Typically, karst collapse potentials are evaluated by scoring a set of risk factors on the basis of casual observation. It is known that the likelihood of a collapse occurring is directly related to several factors including overburden characteristics, depth to groundwater, weather, geologic setting, and karst development. These factors must be identified and quantified or normalized in order to be utilized in an analytical method. Methods of analysis include measuring and normalizing geologic outcrop patterns, identifying water wells that intersect karst features, and developing spatial databases of existing springs, sinkholes, geologic structural features, and other factors. This presentation will discuss the use of spatial and cultural information, associated databases, hazard, risk, and vulnerability analysis.