洞庭湖生态经济区景观生态风险评价

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

根据景观生态风险的变化规律,对洞庭湖生态经济区的生态风险进行合理评估,对于洞庭湖生态经济区的生态发展有着重大的意义。基于1985年、2005年和2015年三期遥感影像,利用GIS技术和地统计学,构建生态风险指数,分析洞庭湖生态经济区景观格局,对洞庭湖生态经济区景观生态风险进行评价。结果表明:随着人类活动的加剧和"平垸行洪、退田还湖"政策的实施,洞庭湖生态经济区的建设用地和水域面积持续增加,分别增加了13.17万hm2和21.63万hm2;研究区域的景观生态风险状况从以较低生态风险和中等生态风险为主发展至较低生态风险、中等生态风险和较高生态风险并存的格局,同时高生态风险区域面积也有所增加;在后期,由于国家在此区域设立自然保护区以及加强部分地区的生态保护,低生态风险区和较低生态风险区的面积有所回升;因此在洞庭湖生态经济区的发展期间,要对区域生态风险进行定期监控。

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 13.17×10^4 hm^2 and 21.63×10^4 hm^2 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 21 st 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.