Abstract:
The impacts of global climate change on different regions are diverse and complex. Research on climate and hydrological elements in large-scale watersheds can reveal the manifestations and impact mechanisms of climate change in specific regions, providing scientific basis for formulating regional response strategies. Poyang Lake is one of the important sub basins of the Yangtze River, and its hydrological changes directly affect the water quantity and quality of the Yangtze River. Based on the GEE (Google Earth Engine) platform, daily precipitation and temperature data of the Poyang Lake Basin from 1981 to 2022 were obtained. Ten precipitation indicators and six temperature indicators were selected, and the spatiotemporal variation characteristics of precipitation and temperature in the Poyang Lake Basin were analyzed using linear trend method, moving average method, and Mann-Kendall trend test method. The research shows that from 1981 to 2022, the annual precipitation and the precipitation in flood season in Poyang Lake Basin will not increase significantly, and the number of regular precipitation days will not decrease significantly, but the number of rainstorm days and rainstorm will increase significantly. Precipitation shows a spatial trend of increasing in the east and decreasing in the west, increasing in the north and decreasing in the south, and decreasing from the northeast to the southwest of the watershed. The temperature in the Poyang Lake Basin is showing a warming trend, with severe interannual variations in extreme temperatures (highest and lowest), a significant increase in extreme high temperature days, and a decrease in low temperature days. The temperature in the watershed shows a spatial pattern of high in the middle and low in the surrounding areas, with significant spatial variations in persistent temperature indicators influenced by geographical location factors. The research results can enhance the understanding of the hydrological cycle characteristics and changes in the Poyang Lake Basin, and provide reference for the development of water resource management and flood and drought disaster prevention measures in the basin under the influence of climate change.