Simulation of urban agglomeration ecosystem spatial distributions under different scenarios: A case study of the Changsha-Zhuzhou-Xiangtan urban agglomeration

Changsha-Zhuzhou-Xiangtan is an urban agglomeration along the middle reaches of the Yangtze River, the development plan of which is listed as one of national strategic development. The eco-environmental quality of the Changsha-Zhuzhou-Xiangtan urban agglomeration concerns the ecological security of China. It is essential to discuss the method of creating urban agglomeration plans to increase ecological security. In this paper, the ecosystem distributions were mapped using the CLUE-S model incorporated with Gray Model (GM) (1, 1) and an auto-logistic regression model under the conditions of a natural increase scenario (NIS), a cultivated protection scenario (CPS) and an ecological protection scenario (EPS). We analyzed the change and conversion characteristics of ecosystems both in the study area and the junction of Changsha, Zhuzhou and Xiangtan. The results showed that the ecosystem change model developed in this paper performed well in mapping future urban ecosystem distributions. The change of the ecosystem spatial distributions showed us that the built-up ecosystem would expand in the future by transforming cultivated and green land ecosystems and that the boundaries between cities would be blurred. In the whole study area, the amount of converted area from cultivated and green land to built-up land was lower in CPS and EPS than in NIS. However, in the key area, the converted result was contrary to the whole study area. Although the CPS and EPS were beneficial to the eco-environmental protection of the whole study region, the sub-regional eco-environment should be given more attention to assure that the ecological security of the whole region remains safe.