Evaluation of landscape ecological risk in key ecological functional zone of South–to–North Water Diversion Project, China

Abstract

The key ecological functional zone plays a significant role in maintaining ecosystem security, water conservation function and environmental protection. However, owing to rapid industrialization and urbanization, some ecological functional zones have undergone great changes in land use, which has changed the landscape pattern characteristics and resulted in ecological risks, affecting the regional ecological environment and water security. In this study, the core water source area of the Middle Route of China’s South–to–North Water Diversion Project is selected as the case study. A regional landscape ecological risk index (ERI) was constructed to evaluate the landscape ecological risk driven by land use transformation. Moreover, the ERI's spatiotemporal characteristics were investigated using a combination of geographic information systems and geostatistical techniques, which reveal the dominant land use function types associated with ecological risks and their causes. We found that (1) there was not a notable shift in land use, and the level of ecological risk increased slightly from 2010 to 2015. The conversion of previously unproductive land into places for industrial production land and agricultural productive land played a significant role in this phenomenon. From 2015 to 2020, the Danjiangkou Reservoir officially started operation. Furthermore, the improvement of residents’ awareness of environmental protection and natural forest land significantly reduced the ecological risk. (2) The ecological risk has a strong positive autocorrelation, exhibiting a pattern of high in the east and center, low in the west and periphery. (3) An obvious corresponding relation exists between the impacts of topography, soil, and climate on patterns of land use and ecological risk. Additionally, the strict ecological protection policies implemented by the Chinese government have realized remarkable achievements in promoting the improvement of ecological risks. Our study can provide a decision–making basis for the local authorities to conduct ecological risk prevention activities and ensure the sustainable northward flow of clean water.