Creating Water Body Maps for the Pacaya Samiria, the Everglades, and the US Gulf Coast using NASA UAVSAR Imaging Radar Data

Wetland areas are important ecosystems that are biologically diverse, have profound impacts on the global carbon cycle, and provide ecosystem services such as floodwater management. These important ecosystems are at risk due to changes in climate. Advanced remote sensing imaging techniques provide sources for greater mapping capability of these wetlands. The objective of this research is to develop a technique for mapping wetland-dominated regions, including areas of open water and inundated vegetation. This study focuses on the detection of surface water by using datasets from NASA's Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) and software tools such as ASF's Map Ready, PolSAR Pro, and ENVI. Within wetlands regions, the delineation of open water and inundated vegetation is accomplished using the Freeman and VanZyl polarization decomposition models, through application of PolSAR Pro. The Freeman and VanZyl decomposition models decompose the polarimetric radar scattering measured by UAVSAR into three different scattering components (double-bounce, single, and volume) which are related to different land cover classes and their inundation state. Test areas and regions of interest were selected in the Everglades, the Pacaya Samiria, and the Gulf Coast (Mississippi Delta) using the decomposition models as a basis. Different polarization bands (HH, HV, and VV) and band ratios (HH-HV, HH-VV) were also used to determine different areas of land cover using ENVI. Water body maps were developed based on the threshold values selected using backscatter histograms of the areas and then compared to unsupervised and supervised methods of land classification.