Remote Sensing Analysis of the Relationship between Sand Dune Topography and Vegetation Response to Varying Precipitation in the Central Great Plains

Abstract

The Central Great Plains is a premier site of sand dune landscapes. These sand dunes are largely covered by native vegetation and as a result, are often used for livestock grazing. The beef industry is an important sector to the region, thus, the maintenance of these landscapes could potentially be important for this region’s economy. The Nebraska Sandhills have been shown to be influenced by their environmental conditions in the past. As climate change produces extremes of weather, these sand dunes are vulnerable to activation and transportation by wind or water. The objective of the proposed project is to determine how sand dune topography and precipitation levels affect vegetation growth, a key protector against soil erosion. The project will investigate this relationship in reference to crests and interdunes and during years of drought and heavy rain. To answer our research question, we analyzed NDVI data (used as a proxy for vegetation growth) available for sand dune fields near two Nebraska villages in Google Earth Engine. We hypothesized that crests will experience more of a vegetative reaction to the varying levels of precipitation due to increased exposure to the elements (e.g. wind). However, our results suggest the contrary and, in fact, interdunes had a greater reaction. Our statistical analyses show that this difference between the dune features is significant (p-value <0.05). Our results affirm the relationship between precipitation and vegetation growth previously established in other studies and imply topography plays a bigger role in sand dune vegetation growth.