USING SUPERVISED CLASSIFICATION TO DELINEATE THE GYPSUM DUNE FIELD BOUNDARY AT WHITE SANDS NATIONAL PARK

White Sands National Park contains part of the largest gypsum dune field in the world. This rare geologic feature is stabilized by groundwater, and is therefore susceptible to increased water withdrawal and changes in climate. Without water to give structure to the dunes, the gypsum sand would be subject to accelerated erosion during the high wind events that occur in southern New Mexico.

The primary aim of this work was to establish a method for monitoring changes to the stability of the dune field. We used USGS Landsat data to develop a Random Forest classification model that identifies the boundary of the dune field. To establish a baseline for future comparison, we ran the model against data from 2013, 2017, and 2020 aggregated at the monthly level. The results show negligible variation in the dune field area during this period, with a 1.9% decrease between 2013 and 2020. In addition to monitoring changes in area, the model also allows us to identify locations of potential dune migration, as well as seasonal fluctuations in the dune field extent.