On the Land-Atmosphere Water and Energy Exchange – Land Use/Cover, Drought and Water-Related Index(2/2)

This project is designed to study the relationship between land use/cover (LULC), water related index and drought under the framework of land-atmosphere water and energy exchanging system. Long-term energy flux data will be utilized to answer a critical question how LULC changes affect energy partitioning and what impacts they play in regional and global climates. We propose a three-year project to investigate how heterogeneous LULC and climate factors alter energy partitioning, quantify durations and intensities of drought, and understand how LULC changes affect regional and global climates based on the long-term data from our ASOS（Automated Surface Observing System） sites and HiWATER（Heihe Watershed Allied Telemetry Experimental Research） project. We will combine the analysis of latent heat fluxes and LULC with Normalized Difference Latent Heat Index（NDLI）. Hence, the first-year（2019/8-2020/7） plan is to use long-term observations to compare the effects of different LULC on energy allocation under different climatic conditions, and explore the effects of natural factors（climate conditions） and human factors（LULC） on energy allocation. We will combine the NDLI's surface covering analysis capabilities and use the newly defined land use drought indicators to analyze the impact of land use on Bowen ratio. In the second year（2020/8-2021/7）, we add more surface station observations of different LULC and climatic conditions, analyze long-term LULC change, quantify the impact of drought on different LULC, and analyze LULC changes to natural factors (such as rainfall and temperature) and drought and NDLI Impact. In the third year（2021/8-2022/7）, under different spatial and temporal scales, we will analyze the impact of land use on drought, integrate the surface distribution characteristics of NDLI, and improve a new Bowen ratio model for characterizing drought based on climate and LULC factors. By these comprehensive analyses, it is expected to have significant benefits for drought disaster reduction, heat island effects, and national land and water resource plans.