Evaluation of ecological changes based on a remote sensing ecological index in a Manas Lake wetland, Xinjiang

Wetlands are important, unique, multi-functional ecosystems formed by the interaction between land and water on the earth. They are an important habitat for human beings, with one of the highest productivity and richest biodiversity in the natural world. In the past 50 years, with the large-scale development of land resources in the Manas River Basin, the agricultural production water in the upper and middle reaches has reached downstream ecological habitats, resulting in a loss of biodiversity in the Manas Lake wetland and increased desertification at the lakeside. The ecological environment is the material basis for the survival and development of humans, and ecological environmental quality has a profound impact on global change and regional sustainable development. The remote sensing ecological index(RSEI), integrates multiple indicators that reflect the most intuitive ecological environment based on natural factors, and can quickly monitor and evaluate the regional ecological environment. Based on Landsat remote sensing images from 2000, 2006, and 2016, this study used the RSEI index to monitor and evaluate the ecological environment quality of the wetland at Manas Lake. The results showed that the RSEI index established by integrating the vegetation index, humidity, land surface temperature, and soil index using the principal component analysis technique has certain applicability, and could effectively be used to monitor and evaluate the ecosystem quality and its spatio-temporal changes in this wetland. In 2000, 2006, and 2016, the average RSEI index was 0.227, 0.183, and 0.234, and after ranking the RSEI index, it was found that the "lower" grade of the ecological environment in the river basin was dominant. The "excellent" level has increased, and the eco-environmental quality in the basin has improved. Climate change and human activities play a role in the eco-environmental effects produced in the Manas Lake wetland; increasing human activity is the main cause of wetland degradation, and extensive agricultural development over time has severely misaligned the population, economic, and ecological environment of the Manas River Basin. In the new century, under the "Five in One" modernization of the country to optimize the allocation of water resources, this paper focused on the large-scale development of water and land resources in major river basins, with the primary aim of determining the ecological value and sustainable development of the tail la