Investigating the Relationships Between Vegetation, Water Use, Habitat Quality, and Conservation Across the United States — Mexico Border Region

Abstract

The United States-Mexico transboundary region comprises myriad land covers withdistinct ecosystems, with the desert biome characterized by limited water resources. Water availability plays a vital role in evapotranspiration (ET) and is essential for determining environmental conservation strategies and sustainable management decisions. This study quantifies ET across his diverse landscape using a decade of Landsat 8 Operational Land Imager (OLI) data (2013–2022) at 30-m resolution, and climatological data from the 1-km resolution DAYMET dataset to compute ET. The empirical Nagler ET model developed using the Moderate Imaging Spectroradiometer (MODIS) was applied with Landsat to estimate ETa. A newly developed regional land cover map was used in this study to constrain the analysis of Eta patterns for six selected land cover class types as an initial proof-of-concept methodology. The results showed the highest ETa rates in the higher-elevation land cover classes (The Madrean Upper Conifer Woodland and Shrubland) and land cover classes along the riparian corridors (North American Arid West Emergent Marsh, the North American Warm Desert Lower Montane Riparian Woodland and Shrubland), while the lowest are in drier areas (The Sonoran-Mojave Creosotebush–White Bursage Desert Scrub), which reflects the capacity of each land cover class to retain and transpire water. ETa patterns aligned with vegetation indices; an indication that Eta may be considered a reliable metric for estimating land cover conditions to determine general health, habitat quality, and resilience in the face of environmental disturbance and pressures.