Unraveling the Ecological Tapestry: A Comprehensive Assessment of Changtang Nature Reserve’s Ecological and Environmental Using RSEI and GEE

The Changtang Nature Reserve, located in the hinterland of the Qinghai-Tibet Plateau, plays a crucial role in researching ecological and environmental assessment on the plateau. However, the severe natural conditions in the Changtang Plateau have resulted in the absence of meteorological observation stations within the reserve, thereby leading to a lack of fundamental ecological and environmental research data. Remote sensing technology presents an opportunity for ecological monitoring in the Changtang Nature Reserve. In this study, remote sensing ecological indices (RSEI) were utilized to evaluate the ecological environment of the reserve from 2000 to 2020. The MODIS data reconstructed using the Savitzky-Golay filter on the Google Earth Engine (GEE) platform were employed. Principal component analysis was then conducted to construct the RSEI. The results reveal that the overall ecological environment quality in the Changtang Nature Reserve between 2000 and 2020 was relatively poor. Over the past two decades, the mean RSEI of the reserve exhibited a fluctuating trend of decrease and increase, indicating a deteriorating and subsequently improving ecological environment quality. Specifically, during the period of 2000–2010, the RSEI mean decreased from 0.3197 to 0.2269, suggesting degradation of the ecological environment, and the proportion of areas classified as fair and poor increased by 51.99%, while the proportion of areas classified as good and excellent decreased by 32.69%. However, from 2010 to 2020, it increased from 0.2269 to 0.3180, indicating an improvement in the ecological environment, and the proportion of areas classified as good and excellent increased by 6.11%, while the proportion of areas classified as fair and poor decreased by 2.91%. Spatially, the core zone demonstrated higher ecological environment quality compared to the experimental and buffer zones. The findings of this study provide comprehensive and accurate information about the ecological environment, which supports management, decision-making, and emergency response efforts in the Changtang Nature Reserve. Moreover, it offers a scientific basis for conservation and sustainable development strategies in the reserve. The quantitative assessment of the ecological environment dynamics contributes to the understanding of the reserve’s ecological dynamics and facilitates informed decision-making for effective conservation and management practices.