Spatiotemporal change detection of ecological quality and the associated affecting factors in Dongting Lake Basin, based on RSEI

Maintaining optimal ecological security in Dongting Lake Basin is of great significance to national projects of Yangtze River Economic Belt Construction and Yangtze River Protection. Ecological quality and the potential associated affecting factors are important contents of ecological security in Dongting Lake Basin. In this research, remote sensing ecological index (RSEI) were used to analyze the temporal and spatial variation in the ecological qualities in Dongting Lake Basin during 2001–2019 and determine the potential associated affecting factors. Results showed that the overall ecological quality fluctuated during 2001–2019. The change intensities among different RSEI levels were relative low (absolute change values of 1 and 2) and mainly changed among fair, moderate and good levels. Land use/cover, climate (average annual rainfall) and human interferences (GDP) were the associated potential factors affecting the ecological quality in Dongting Lake Basin. Among these factors, areas and qualities of woody savannas, savannas, mixed forests, and cropland/natural vegetation mosaics were the most important factors affecting the ecological quality (RSEI). While other land use/cover (i.e., Croplands, Evergreen Needleleaf Forests, Parmanent Wetlands, Grasslands), climate (average annual rainfall) and human interferences (GDP) also had contributions to the ecological quality. Specifically, such four land use/cover, average annual rainfall were positively but GDP negatively correlated with the ecological quality. In conclusion, changes in the area and quality of different land use types might explain most of the ecological quality variations in Dongting Lake Basin. These findings will provide significant information for managers to make more targeted ecological restoration efforts in Dongting Lake Basin.