[A-CG41] 衛星による地球環境観測

[ACG41-14] Analysis of the water color variations in Baiyangdian Lake in the past four decades from Landsat

*Yelong Zhao¹ (1.Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences)

キーワード：Forel-Ule Index, Landsat, Baiyangdian Lake, Xiong’an New Area

Baiyangdian Lake is the largest freshwater lake in the urban agglomerations of Beijing, Tianjin and Hebei province. It plays an increasingly vital role in mobilizing the water supply, supplying water for reed growth, increasing groundwater supply, improving the local climate system, protecting biodiversity, etc. Here, Landsat5 TM, Landsat8 OLI and Landsat9 OLI-2 launched in 1984, 2013 and 2020 were used to track the past four decades variations in water color. Water color has been recognized as an increasingly vital parameter for evaluating the water quality of lakes, reservoirs and ocean. Forel-Ule Index (FUI), as an important water color parameter to evaluate water quality, is a useful parameter that obtains past four decades variations in water quality. In the study, the time series of FUI yearly product were produced for Baiyangdian Lake in the past four decades. And the spatial and temporal variations of water color in Baiyangdian Lake and its driving forces (precipitation, water level, water storage, water temperature, runoff, wind speed, landscape pattern) were analyzed, especially after the establishment of Xiong’an New Area. The results showed that FUI exhibited a spatial distribution pattern with low in the south and high in the north. And FUI exhibited the trend of firstly increasing and then decreasing after the establishment of Xiong’an New Area. The water quality is greatly affected by natural factors such as precipitation, wind speed in Baiyangdian Lake. The study provides the firstly analyze of the temporal and spatial variations of FUI in Baiyangdian Lake in the past four decades, and FUI results and driving factors analyze could facilitate local water resource conservations.