On the Land-Atmosphere Water and Energy Cycle – Land Use/Cover and Drought

In this project, we aim to study the relationship between land use/cover (LULC) and drought under the framework of land-atmosphere water and energy cycle. Long-term energy flux data will be utilized to answer a critical question how LULC affects energy partitioning and what impacts they are in regional and global climates. We propose a three-year project to investigate how heterogeneous LULC and climate factors alter energy partitioning, quantify duration and intensities of drought, and understand how LULC changes affect regional and global climates based on long-term data from our ASOS (Automated Surface Observing System) sites and HiWATER (Heihe Watershed Allied Telemetry Experimental Research) project. Hence, the first-year (2018/8-2019/7) plan is to analyze the data from our ASOS sites to understand the partitioning of surface energy in response to different climates and LULC changes and the associated signatures of Bowen ration, base of a newly-developing drought index. That is, a landuse-adapted drought index will be developed to study what impacts LULC would have on Bowen ratio. In the second year (2019/8-2020/7), we will evaluate LULC changes’ impacts on drought events through comparing new drought index before and after land use changes. Then, we can assess combined impacts from natural drought and anthropogenic drought. In the third year (2020/8-2021/7), under different spatial and temporal scales, we will evaluate these terrain change’s effects on drought occurrence, and develop a new Bowen ratio model based on climate and land cover 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.