Ying Huanchang, Wang Shenglei, Zhang Bing, Mao Zichen, Zhang Fangfang, Li Junsheng
Key Laboratory of Digital Earth Science, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing, 100094, China; International Research Center of Big Data for Sustainable Development Goals, Beijing, 100094, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
Key Laboratory of Digital Earth Science, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing, 100094, China; International Research Center of Big Data for Sustainable Development Goals, Beijing, 100094, China.
J Environ Manage. 2024 Nov;370:122809. doi: 10.1016/j.jenvman.2024.122809. Epub 2024 Oct 8.
Water colour has been recognized as one of the most important Essential Climate Variables of the lake ecosystem, as it is directly related to changes in water constituents and almost all of the lake's ecological changes could alter water colour. Given the high retrieval accuracy from existing Earth observation satellite data, water colour, in terms of Forel Ule Index (FUI), can be a realistic indicator to track the long-term changes in the lake ecosystem and further explore the lake response to environmental changes. This paper aims to comprehensively investigate the spatiotemporal variation patterns of FUI in 159 large lakes (≥25 km) across China during 2000-2022 based on the MODIS data and detect the climatic and anthropogenic driving forces of these changes. The 23 years of MODIS records revealed an overall downward trend of lake FUI across China, indicating the lakes in China shifted to bluer colour during the past two decades. Through driving factor analyses, the complicated interplay among lake colour, lake morphology, regional climate shifts and human interference dynamics was uncovered. In the long term, it was found the pronounced change in lake colour in the western lake zones was primarily attributed to climate warming and humidification, whereas that in the eastern lake zones was mainly related to the alterations in regional land cover during the past two decades. Seasonally, lake basin's air temperature was identified as the main factor impacting the seasonal patterns of lake colour, followed by wind speed and runoff. Spatially, there was high spatial variability in lake colour across China, which was mainly associated with lake elevation and lake basin's precipitation rate, although the factors exhibited considerable divergence across different zones. Based upon the above findings, the implications for lake environment protection and management in different regions of China were further discussed.
水色已被公认为湖泊生态系统最重要的基本气候变量之一，因为它与水体成分的变化直接相关，而且几乎所有湖泊的生态变化都会改变水色。鉴于现有地球观测卫星数据的高反演精度，就福尔指数（FUI）而言，水色可以作为追踪湖泊生态系统长期变化以及进一步探究湖泊对环境变化响应的一个现实指标。本文旨在基于中分辨率成像光谱仪（MODIS）数据，全面调查2000年至2022年期间中国159个大型湖泊（≥25平方千米）的福尔指数的时空变化模式，并检测这些变化的气候和人为驱动力。23年的MODIS记录显示，中国湖泊的福尔指数总体呈下降趋势，表明在过去二十年中，中国湖泊的颜色变得更蓝。通过驱动因素分析，揭示了湖泊颜色、湖泊形态、区域气候变化和人类干扰动态之间复杂的相互作用。从长期来看，发现西湖区湖泊颜色的显著变化主要归因于气候变暖和湿润，而在过去二十年中，东湖区湖泊颜色的变化主要与区域土地覆盖的改变有关。季节性方面，湖盆气温被确定为影响湖泊颜色季节模式的主要因素，其次是风速和径流。在空间上，中国湖泊颜色存在高度的空间变异性，这主要与湖泊海拔和湖盆降水率有关，尽管不同区域的这些因素存在相当大的差异。基于上述研究结果，进一步讨论了对中国不同地区湖泊环境保护和管理的启示。
