[Spatial Relationship between Eco-environment Quality and Land Use Change in Guangdong Province-Hong Kong-Macao, China Based on Remote Sensing-based Ecological Index].

The relationship between eco-environment quality and land use change is an important guarantee for regional sustainable development. Guangdong Province-Hong Kong-Macao have always been closely linked and are now entering a period of accelerated development, but there is a lack of research on the spatial relationship between eco-environment quality and land use change integrated among the three places. Based on historical land use data and Google earth engine （GEE）, MODIS images from the summer of 2000 to 2020 （from June 1 to September 1） were selected （with a time span of five years）. The remote sensing-based ecological index （RSEI） was calculated to characterize the status of eco-environment quality and explore the spatial relationship between eco-environment quality and land use change. The results showed that： ① The land use type in the study area was mainly forest land, which was the base of the northern ecological development area （ecological area） and the northwestern landscape of the Guangdong-Hong Kong-Macao Greater Bay Area （the Greater Bay Area）. The land use degree presented a spatial pattern of "high in the middle, low in the periphery," "high in the south and low in the north," and "high in the southwest and northeast." The intensity of land use change was the least in the ecological area. ② According to RSEI, the regions with an eco-environment quality from low to high were the Greater Bay Area, the eastern wing of the coastal economic belt （east wing）, the western wing of the coastal economic belt （west wing）, and the ecological area. ③ There was a strong negative correlation between eco-environment quality and land use degree. The distribution range of high to low （H-L） cluster was relatively stable, mainly concentrated in the center of the Greater Bay Area, while the distribution of low to high （L-H） cluster was relatively unstable, mainly distributed in the ecological region, and there was no significant correlation between the eastern and western counties, Hong Kong and Macao. ④ The low-value patches of ecological environment quality in Guangdong-Hong Kong-Macao centers were consistent with artificial surface expansion. The center of Foshan in Guangzhou, the eastern part of Shantou, and the southwestern part of Zhanjiang were mainly coupled, while the ecological area, the central part of the east wing, the eastern part of the west wing, and the northwestern part of the Greater Bay Area were mainly uncoupled. Land use change and eco-environment quality were closely related in space. The eco-environment quality of the study area mainly presented a spatial pattern of "high in the middle and low in the north" and "a certain low value in the east." The Greater Bay Area had the lowest eco-environment quality, followed by that of the eastern wing. In the past 20 years, the expansion of low-value eco-environment quality in the center of the Greater Bay Area had formed a continuous landscape base of low-value eco-environment quality. The ecological area had most of the high value areas of eco-environment quality, which provided a large area of ecological environment of good patches for the study area. From 2000 to 2020, there was a significant negative correlation between land use degree and eco-environment quality in the study area, with regional heterogeneity. Land use change is an important factor in the change in eco-environment quality, so it is necessary to focus on the whole planning and layout of land use structure to improve the eco-environment quality.