Ecological sustainability and its driving factor of urban agglomerations in the Yangtze River Economic Belt based on three-dimensional ecological footprint analysis

The impact of human activities on regional resources plays an important role in regional sustainable development, especially in the Yangtze River Economic Belt (YREB) which has an important strategic position in China. Problems such as uneven distribution of resources and unbalanced regional economic development are severe in the YREB. This study applies a three-dimensional ecological footprint model for investigating ecological sustainability of urban agglomerations in the YREB. An appropriate ecological compensation method is used for supporting the sustainable development of the research areas. Simultaneously, a series of ecological compensation schemes among provinces and the corresponding driving factors can be presented. Results show that the average ecological footprint increases from 2.19 ha/cap in 2000 to 3.38 ha/cap in 2015 with a growth rate of 54.34%, in which the Yangtze River Delta City Group and the Middle Yangtze City Group occupy the most of regional ecological footprint growth. The average ecological carrying capacity decreases from 0.205 ha/cap in 2000 to 0.189 ha/cap in 2015, which is mostly contributed by cropland and forest. The factors associated with per capita gross domestic product and consumption levels of urban and rural residents are the main driving factors affecting the ecological footprint. A small ecological footprint can be obtained from the three-dimensional model compared with the traditional model, but it is more accurately reflects the regional real environmental pressure. In terms of ecological compensation, the Yangtze River Delta City Group (−320.74 billion ¥ RMB) is considered as compensation spender, and the Middle Yangtze City Group (228.35 billion ¥ RMB) and the Chengdu-Chongqing City Group (92.39 billion ¥ RMB) are presented as compensation beneficiaries. The YREB is generally in an ecologically unsustainable state, but it is also limited by two main factors related to the rapid economic development and the improvement of people's living standards. Findings are intended to provide references for other similar areas in the world, which are with the problem of unbalanced development between economy and ecology.