GIS ANALYSIS OF SINKHOLE DISTRIBUTION IN NIXA, MISSOURI

Recent sinkhole collapses in the Nixa quadrangle, Southwestern Missouri have triggered the need for detailed sinkhole analysis for the area. New sinkhole maps and a comparison between existing and new maps help to better understand the distribution/pattern of sinkholes in the study area. This study analyzes and compares the sinkhole distribution based on the sinkhole data available from Missouri Department of Natural Resources (MODNR) and Light Detection And Ranging (LIDAR) data available from United States Geological Survey (USGS) on a Geographic Information System (ArcMAP^®) platform.

LIDAR data was used to create a depression-less digital elevation model (DEM) by filling sinks. A DEM subtraction was performed using the original DEM and filled DEM to locate the depressions. The subtracted layer was then processed with different thresholds of elevation differences to map/locate sinkholes. The subtracted layer with 4m threshold value closely matches the current database of MODNR. The layer with 4m threshold produced 221 sinkholes compared to 217 sinkholes listed on MODNR data. This also means that sinkholes mapped with layer threshold below 4m were most probably missed by state database. A proximity analysis was conducted for the depressions that were created with 1, 2, 3, and 4m layer thresholds to study the distribution of sinkholes. Potential new sinkholes were predicted but missed in previous studies. Fine scale details of some sinkholes were mapped correctly using the high resolution LIDAR data.