长江上游地区地表温度变化与驱动因素研究

Study on Land Surface Temperature Variation and Driving Factors in the Upper Reaches of Yangtze River

地表温度(Land Surface Temperature, LST)是研究地表和大气物质和能量交换的重要参数。基于MYD11A2的地表温度数据,结合气温、降水和归一化植被指数(NDVI)数据,利用Theil-Sen趋势法、Mann-Kendall显著性检验法以及相关性分析法,对2003~2021年长江上游地区的年度、昼夜以及四季时间尺度的地表温度变化规律进行分析,并深入探讨了上游地表温度与环境因子之间的关系。研究结果表明:1) 长江上游地区的年均地表温度呈现出明显的西低东高的空间格局,其多年平均地表温度约为10.31℃。2) 在2003~2021年间,长江上游地区整体呈现出升温趋势,升温速率为0.18℃∙10a−1。昼夜地表温度呈现出明显的不对称增温现象,夜间地表温度升温速率远快于白天;变化趋势在四季表现为:夏季 > 春季 > 秋季 > 冬季。除冬季呈降温趋势,夏、春、冬季均呈升温趋势。3) 上游地区地表温度与气温整体呈正相关关系,而与降水和NDVI呈负相关关系。这些结果为我们更好地理解长江上游地区地表温度变化规律提供了重要依据,并为相关地区的生态环境保护和气候适应提供了科学支持。Land surface temperature (LST) is a crucial parameter for studying the exchange of matter and energy between the surface and the atmosphere. The Theil-Sen trend method, Mann-Kendall significance test method, and correlation analysis method were used to analyze the LST data of MYD11A2 in combination with air temperature, precipitation, and the normalized vegetation index (NDVI) data. The study analyzed the annual, diurnal, and four-season time scales of land surface temperature (LST) in the upper reaches of the Yangtze River from 2003 to 2021 and discussed the relationship between LST and environmental factors. The results indicate that: 1) The annual average land surface temperature in the upper reaches of the Yangtze River is lower in the west and higher in the east, with an average of about 10.31˚C. 2) From 2003 to 2021, the upper reaches of the Yangtze River have experienced an overall warming trend, with a rate of 0.18˚C∙10a−1. The land surface temperature (LST) increases asymmetrically between day and night, with a faster increase at night. The seasonal variation trend is as follows: summer > spring > autumn > winter. While winter shows a cooling trend, all other seasons show a warming trend. 3) The surface temperature in the upstream region showed a positive correlation with air temperature, but a negative correlation with precipitation and NDVI. These findings provide a valuable foundation for comprehending the pattern of surface temperature variation in the upper reaches of the Yangtze River. Additionally, they offer scientific support for the protection of ecological environments and climate adaptation in related areas.