Developing a tool to monitor water use efficiency and vegetation greenness in hyper-arid desert using multiple satellite remote sensing data records

Efficient water management is essential for sustaining vegetation in the arid environment of the United Arab Emirates (UAE), where high temperatures and limited freshwater resources intensify the need for optimized irrigation strategies. This study develops a remote-sensing-based monitoring framework to assess water use efficiency (WUE) across the sparsely vegetated landscape of the Al Ain in the UAE. The vegetation of Al Ain is characterized by date palm cultivation and xerophytic species that are physiologically adapted to the desert, wadi, and mountainous environments. Multi-source satellite datasets—including 30 m vegetation indices from Landsat and Sentinel-1 and 1-km evapotranspiration (ET) estimates from the Simplified Surface Energy Budget (SSEBop)—were integrated to quantify spatiotemporal patterns in vegetation productivity and water fluxes. Vegetation greenness and productivity were evaluated using the Normalized Difference Vegetation Index (NDVI) and Radar Vegetation Index (RVI), while ET data captured seasonal variations in soil evaporation and transpiration. Water use efficiency (WUE), expressed as the ratio of GPP to ET, served as a metric for evaluating biomass production relative to water consumption under hyper-arid conditions. Time-series analyses revealed marked seasonal dynamics in NDVI, RVI, GPP, and ET associated with rainfall pulses and irrigation activities. Spatial mapping highlighted variability in vegetation performance and identified zones with potential for improved water-use optimization. The findings demonstrate the value of Earth-observation-driven analyses in characterizing vegetation responses to extreme precipitation events and irrigation practices. The proposed monitoring tool provides a practical foundation for advancing sustainable irrigation planning, enhancing vegetation carbon uptake, and promoting long-term water resource sustainability in Al Ain, UAE.