基于景观格局的锦州湾沿海经济开发区生态风险分析

以辽宁省锦州湾沿海经济开发区为研究区，利用1992、2000和2007年3个时期的TM遥感影像为数据源，通过计算各景观格局指数，引入生态风险指数，利用GIS和地统计学，对生态风险指数进行采样和空间插值，得到基于景观格局的生态风险分布图。运用相对指标法对生态风险指数进行分级，将研究区域划分为低生态风险区、较低生态风险区、中等生态风险区、较高生态风险区和高生态风险区5个等级，在此基础上通过将不同时期的生态风险图层的叠加运算，分析了研究区景观生态风险的时空变化情况。结果表明：近15年来研究区生态风险主要以中等程度为主；处于低、较低生态风险程度的区域面积变化不大，空间分布也一直位于西部低山丘陵地区；较高生态风险区域面积增加较为显著，主要发生在兴城市和绥中县东南沿海地区；高生态风险区面积随着未利用地和芦苇湿地等高生态脆弱性景观类型面积的减少而略有下降。

Assessment of ecological risk of coastal economic developing zone in Jinzhou Bay based on landscape pattern

The ecological risk assessment is currently the advanced method and concept to study the relationship between regional eco-environment and development, but the theoretical research on it is still in its initial phase at present. The quantitative expressions of risk receptor, risk sources and risk effect are the key problems in the theoretical system of ecology risk assessment. Regional ecological risk assessment offers scientific suggestions for ecological risk management. It is used to describe and evaluate the possibility and degree of damage that might be taken to the structure and function of ecological system by environmental pollution, human activities and natural disasters on regional scale. The human economic activities are mainly carried out on the level of landscape, therefore, landscape has become the appropriate scale to study the impact of human on environment. In the landscape dominated by human activities, the ecological effects generated by different land use patterns and intensities usually are regional and accumulative, and they will be reflected directly on the structure and composition of the ecological system. Therefore, we can assess the various potential human influences and their consequences by the structure of the ecological system. We can establish the relationship between ecological system structure and ecological influences by statistical analysis, and the results can make good help for environmental management and ecological risk decision making. Taking the coastal economic developing zone in Jinzhou Bay as studying area, using the remote sensing images of Landsat TM in 1992, 2000 and 2007 as the main date source,the ecological risk index was constructed based on the calculation of the landscape pattern indices, and the distribution level of ecological risk was mapped based on ecological risk index values by GIS and geostatistics. The ecological risk of studying area was classified into five levels, i.e. extremely low ecological risk, low ecological risk, moderate ecological risk, high ecological risk and extremely high ecological risk by relative index method. And then the temporal and spatial dynamics of ecological risk distribution were analyzed by overlying the ecological risk maps in different periods. The results show that: (1) Farmland and woodland were the dominated landscape types from 1992 to 2007, but the area decreased slightly, and the fragmentation of them increased. Residential land take the third place, and the area has increased significantly, at the same time, the connectivity also increased continuously. The area of grassland and unused land reduced year by year, and also the fragmentation increased yearly. (2) In recent 15 years, the moderate ecological risk level covered the biggest area of the study area; the area of extremely low risk and low ecological risk had no obviously change and mainly located in western hills; the area of high ecological risk increased significantly and was mainly distributed in southeast coastal zone of Xingcheng and Suizhong; because of the reduction of high ecological vulnerability, i.e. abandoned land and wetland, the area of extremely high ecological risk also decreased slightly. To obtain the sustainable development of regional land resources, the landscape pattern have to be optimized, and the connectivity of landscape patches should be increased.