[Spatial variation of ecological environment quality and its influencing factors in Poyang Lake area, Jiangxi, China].

Based on Landsat 8 OLI/TIRS remote sensing image data, indices including NDVI, WET, NDSI and LST were selected from the aspects of greenness, humidity, dryness and heat respectively, and remote sensing ecological index (RSEI) was constructed by principal component analysis to analyze the spatial distribution of ecological environment quality in Poyang Lake area in 2014. The spatial heterogeneity and its influencing factors of the original remote sensing ecological index (RSEI0) were quantitatively analyzed using spatial autocorrelation, semi-variance function, maximum information coefficient, and factor detection. The results showed that ecological environment quality of Poyang Lake area was generally at a moderate level in 2014 and that the overall spatial distribution pattern from southwest to northeast gradually improved. The exploratory spatial data analysis showed that RSEI0 had strong spatial clustering and spatial heterogeneity under the sampling of 2 km grid element. The nugget effect value of RSEI0 was 25.8%, which belonged to medium spatial variability and was mainly affected by structural factors. The results of maximum information coefficient and factor detection analysis showed that slope had the strongest positive correlation with RSEI0. Slope, elevation, curvature, annual average rainfall, annual average temperature, proportion of garden forest area, proportion of cultivated land area, proportion of construction land area, annual average population density and annual average GDP significantly affected RSEI0, but with different magnitude of influences. Among them, the slope independent explanatory power was 57.1%, which was the main factor affecting spatial variation of RSEI0 in Poyang Lake area. Our results could provide reference for the protection and management of ecological environment in the Poyang Lake area.