Coupling Land Use Analysis and Ecological Risk Assessment: A Study of the Three Gorges Reservoir Area, China

Exploring the ecological response of land use change is important for regional sustainable development and assists in understanding the profound consequences of this change. This paper proposes coupling a study of the evolution of land use with an assessment of ecological risk, based on a typical watershed in the hinterland of China's Three Gorges Reservoir area. Land use data for the Caotangxi watershed derived from Landsat images from 1990, 2000, 2004, and China-Brazil Earth Resource Satellite data from 2010 and 2016 were used to identify ecological risk based on land use changes. The spatial interaction process between land use and ecological risk changes from 2 spatial scales of grid and terrain was analyzed using geographic information system technology and an ecological risk index. The study area's ecological risk index demonstrated at first a worsening trend and then improvement during the period from 1990 to 2016. During 2004, there was a turning point in ecological risk evolution; this was most apparent in zones with a slope of 15-25 and >25 degrees, as well as in the elevation zone between 300 and 1000 m. The proportion of serious-risk areas decreased sharply after 2010, and land function transformation resulted in improvement of ecological risk in the watershed during the 26 years from 1990 to 2016. Our study provides support for evaluating ecological risk trends and the development of land use transition theory in the Three Gorges Reservoir area. It is a typical description of land remediation and ecological restoration in this area.