ANALYZING LIDAR SLOPE DATA TO CREATE GEOLOGIC MAPS

Slope data derived from a LiDAR dataset was analyzed to create a geologic map based on erosion patterns. The research area is located in south east New Mexico in the western extent of the Guadalupe Mountain range. The strata found in this region are similar to that exposed along the eastern edge of the Guadalupe Mountains. This project focused on the western escarpment that is primarily in the Pinon Ranch Quadrangle. Background research over the study area was conducted and various digital maps were downloaded (topographic, geologic, etc.). The LiDAR bulk data was obtained from the OpenTopography web site and imported to an Arc GIS system. From this basic data elevation chloropleth maps and a 3-D TIN model were created and analyzed in order to better understand the area. With these maps Slope Class-Breaks of grouping by degrees of slope were then manually determined using topographic slope data compared to descriptions of local geology. A geologic map was then built using the class breaks as a proxy for formations and members. This highlighted the ridge line of the Rio Bonito Member which has the steepest slopes in the study area. A trip was then made to the study area to ground truth the multiple maps that were created in the lab. Field observations found that the initial LiDAR slope mapping hypothesis generally holds true. Other factors such as vegetation type and drainage patterns are also being evaluated as indicators of underlying geology that can be examined with LiDAR.