Spatiotemporal dynamics of the ecological condition and the associated affecting factors based on mRSEI in the Tianshan Mountains from 2000 to 2022

This paper presents the research outcomes from the eco−geological survey project.

Objective The Remote Sensing Ecological Index (RSEI) is a crucial indicator reflecting ecological environment quality. The Tianshan region features fragile ecosystems and prominent salinization issues. The modified Remote Sensing Ecological Index (mRSEI) can characterize the specific attributes of the arid Northwest China region, providing a more precise representation of its ecological environment quality.

Methods Situated in the arid Northwest China, the Tianshan region was studied to accurately assess its ecological quality. This research investigated the ecological environment quality of the Tianshan region from 2000 to 2022 based on the spatiotemporal changes in mRSEI, its driving factors, and its response to these drivers. The natural breaks classification method and grading were employed to evaluate ecological quality within different intervals of specific factors. The coefficient of variation and the Hurst index were utilized to examine the fluctuation trends of Tianshan's mRSEI and predict its future fluctuation patterns. GeoDetector (GD) and the Random Forest (RF) model were applied to identify the dominant factors influencing changes in the Tianshan region's mRSEI.

Results From 2000 to 2022, the mRSEI in the Tianshan region exhibited a slow increase with irregular fluctuations over time. Spatially, it displayed a distribution pattern characterized as "higher in the west than in the east, and higher in the north than in the south". Predicting future mRSEI trends proved challenging. The responses of mRSEI to human activity factors in the Tianshan region were primarily linear. Evapotranspiration, temperature, slope, and DEM were identified as the primary factors influencing regional mRSEI; however, the response trends of mRSEI varied for different factors.

Conclusions The mRSEI enables the scientific monitoring of the spatial distribution of ecological environment quality in the Tianshan region, located within the arid Northwest China. It facilitates an accurate grasp of ecological quality change trends and can provide theoretical support for ecological conservation efforts in the Tianshan region.