Ecological risk assessment based on landscape pattern for Dongting Lake Ecological Economic Zone

Assessment of ecological risk of Dongting Lake Economic Zone is critical for the ecological development of Dongting Lake Economic Zone. Three Landsat TM images of 1985, 2005 and 2015 were utilized to identify land use / land cover. GIS technology and geostatistics were applied to construct the ecological risk index and analyzed the landscape pattern of Dongting Lake Economic Zone. Spatial distribution of ecological risk in Dongting Lake Economic Zone was further explored. The results showed that with the increase of human activities and the implementation of the policy of “Flatting embankment for flooding control and returning farmland to the lake”, the built-up land and water area of Dongting Lake Eco-economic Zone continued to increase, increasing by 13.17×104 hm2 and 21.63×104 hm2 respectively. Approximately 30 years ago, dominant areas had low ecological and medium risk. In contrast, areas of low and high ecological risk coexisted in 2015. At the same time, the area of high ecological risk area had also increased. In the 21st century, Due to the establishment of nature reserves in this region by the state government and the strict implementation of ecological protection in selected regions, the areas of low-ecological risk areas and low ecological risk areas had increased.