Abstract: The interrelation between socioeconomic and environmental conditions and ecological carrying capacity is one of the most important themes of sustainable development studies in recent years. At different spatial and temporal scales, ecological carrying capacity responds to regional social, economic, and environmental changes in varying degrees. Using sustainable development index and ecological carrying capacity response model, the social, economic, and environmental changes and corresponding ecological carrying capacity change of the Dongting Lake Region from 2001 to 2010 were analyzed. The results indicate that: (1) For the lake region as a whole, economic development degree and social harmonization degree showed an upward trend; integrity and sustainability of ecosystems showed an positive change; while environmental sustainability degree declined. (2) Development degree, harmonization degree and sustainable degree of 17 counties of the Dongting Lake Region showed an upward trend; in the urban areas of Yueyang, Changde and Yiyang development and harmonization degrees were higher than the other 14 counties, while environmental sustainability degree decreased most significantly. (3) Ecological carrying capacity was divided into four categories: severely overload, overload, slightly under-load and under-load. The urban areas of Yueyang, Changde and Yiyang had higher levels of socioeconomic development, but the status of their ecological carrying capacity was severely overload, which indicates that economic development, social progress, resource use and environmental quality were poorly balanced. (4) Regression analysis of ecological carrying capacity, economic development degree, social harmonization degree, environmental sustainability degree, and sustainable development index show that, to some extent, environmental sustainability degree became an important foundation for improving ecological carrying capacity. The present destructive economic development model has become an obstacle for enhancing ecological carrying capacity. Due to the fact that the rapid socioeconomic development depends too much on resource exploitation and disturbances to the regional environment and ecology, the influence of environmental sustainability on ecological carrying capacity and sustainable development index is rather weak and economic development is largely at the cost of the ecological environment. This result provides a basis for the country to implement the scientific concept of development, build a harmonious society and achieve sustainable development of its regional economy, society, environment and ecology.

Key words: Dongting Lake Region, ecological carrying capacity, economic development degree, environmental sustainability degree, response, social harmonization degree