Author(s): Youngwook Kim; Abdalla Saber Abdalla Abdelhamid; Benazir Meerasha; Young Ki Kim; Ashley Kim
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Keywords: No Keywords
Abstract: Seasonal dynamics and inter-annual variation of vegetation productivity is closely linked with temperature variations in most of terrestrial biomes, but soil water moisture is an additional factor to determine eco-hydrological processes in the water-limited regions. Studies using in-situ observation and satellite remote sensing have been widely used to monitor temporal variations of terrestrial ecosystem productivity and associated biogeochemical processes, including carbon and water cycles. However, there are few studies on the changes of seasonal eco-hydrological dynamics and the resulting biogeochemical cycles, and associated hydroclimate impacts on dryland ecosystems, particularly sparsely vegetated areas. In this study, we used optical and microwave satellite remote sensing data records, to monitor spatial and temporal patterns of surface soil moisture (SFSM), root-zone soil moisture (RZSM), vegetation greenness and evapotranspiration (ET) associated with regional carbon and water cycles over a sparsely vegetated area of the United Arab Emirates (UAE). The multi-source satellite data records include the six-year (2016-2021) surface soil moisture, and optical- and microwave-based vegetation index (VI) and ET derived from MODIS, LANDSAT-8, and Sentinel-2. We also used Delta-T WET-2-K4 sensor to measure in-situ surface soil moisture at the sparsely vegetated site in Al Ain, UAE. The surface soil moisture measured represents the point-level water content in the surface soil (~5cm depth). The combined satellite remote sensing data provide the enhanced ability to monitor vegetation dynamics and biogeochemical cycles. The results will show a better understanding of how the seasonal responses of the vegetation productivity, ET, and carbon and water cycle feedback to hydro-climate change. Knowledge obtained from this study will provide important insights for future feedbacks and their consequences on biogeochemical dynamics in hyper-arid ecosystems.
Year: 2024