Abstract: The rapid monitoring and quantitative evaluation of eco-environmental quality change can provide decision support for regional ecological environment collaborative governance and management policy formulation. Based on Landsat5/TM and Landsat8/OLI images, using Google Earth Engine (GEE) platform and Remote Sensing Ecological Index (RSEI), comprehensively considering various eco-environmental factors such as humidity, greenness, dryness, and heat, we quantitatively evaluated the changes of eco-environmental quality in the Yangtze River Delta integration demonstration area from 2000 to 2020. We analyzed the effects of social and economic factors on eco-environmental quality by combining GDP and population data. The results showed that greenness contributed most and positively to the eco-environmental quality of the study area. Thermal index was the main factor resulting in the degradation of regional eco-environmental quality. The eco-environmental quality of the study area was generally at a medium level, which showed a steady upward trend during 2000-2020. Specifically, the eco-environmental quality of Qingpu District increased obviously, while that of Wujiang District and Jiashan County decreased slightly. From 2000 to 2020, the proportion of areas with improved eco-environmental quality (30.45%) was slightly higher than that of degraded area (28.35%), and the proportion of areas with good and excellent grades increased from 27.34% to 29.79%. There were significant differences in eco-environment quality among districts/counties and towns in different periods. Population growth had a significant negative impact on eco-environment quality. Economic development was not at the cost of eco-environment, and the relationship between economic development and eco-environment quality was decoupled.

Key words: eco-environmental quality, remote sensing based ecological index, Google Earth Engine, Yangtze River Delta integration demonstration area.