洞庭湖区湿地生态系统健康综合评价

Assessment and analysis of wetland ecosystem health in Dongting Lake

湿地与海洋、森林并称为地球三大生态系统,湿地退化速度远大于其他生态系统,从而使得湿地健康评价与分析成为湿地领域研究的重点内容之一。本文以生态系统健康及压力-状态-响应模型为研究方法,综合利用遥感、野外实测和社会统计等多源数据,建立一套湿地生态系统健康评价指标体系,集成利用遥感和地理信息技术建立湿地生态系统健康评价模型,实施湿地压力、状态、响应、健康分析,揭示了洞庭湖湿地生态系统健康状况的空间分布规律。研究结果表明:(1)洞庭湖区31%的湿地面临人类干扰压力较大,19%的湿地状态较好,82%的湿地生态系统发生很大变化。(2)湿地的总面积在人类活动的干预下逐渐缩小,湿地综合健康较差、一般和较好的区域分别占总面积的6%、75%和19%,缺乏健康状况最好及最差的区域。(3)湘阴县、沅江县及岳阳县的湿地生态系统健康状况较好,益阳县较差,安乡县等12个县市一般。

Wetlands are one of the most important ecosystems on Earth and the major feature of the landscape in almost all parts of the world, which is very important to the sustainable development of anthropogenic society at a regional or global scale. Taking Dongting Lake as a study region, this paper firstly established evaluation indicators of wetland health concerning hydrology, ecology and environment according to the feature of wetlands and principle of PSR （Pressure-State-Response） model. Secondly, multi-temporal remote sensing data were acquired by TM （Thematic Mapper） sensor onboard of American Landsat satellite system, geographical data, land use/cover data, field detection data and social statistic data. Thirdly, special information of each evaluation indicator was extracted from different data sources and analyzed. Finally, a PSR model supported by GIS was used to evaluate and analyze wetland ecosystem health. The results show that the areas with better, generic and worse health conditions account for 19%, 75% and 6% of the total area respectively, and that there are no areas with best and worst health conditions. The wetland ecosystem health condition is better in Xiangyin County, Yuanjiang County and Yueyang County. The health condition of Yiyang County is worse. The other counties belong to the average grade of health.