基于景观指数的高邮湖湿地生态水文连通性分析

为了定量评价水位的变化和人类活动对高邮湖湿地连通性的影响,基于高邮湖湿地不同景观类型及其时空动态性,利用遥感影像数据的分类解译结果,选择连接度指数CONNECT、斑块内聚力指数COHESION、破碎化指数FN以及分离度DIVISION等指标,构建高邮湖湿地生态水文连通度综合指数CECI,分别对比分析了不同水位和相同水位不同年份下高邮湖湿地生态连通性的变化情况。结果表明:生态水文连通度综合指数CECI可以定量表征湿地生态连通性的动态变化;随着水位上升,高邮湖湿地湖泊与河流的CECI分别从2. 79、0增加到9. 21、6. 75,生态水文连通性逐渐提升;该研究区湖泊与河流的水文连通性变化具有很强的相关关系,湖泊水文连通性优于河流;在水位相同的情况下,从2013年到2017年,由于退圩还湖、退圩还湿等人类活动的影响,高邮湖湿地面积增加,湖泊的CECI从6. 27增加到7. 48,河流的CECI从2. 62增加到4. 61,生态水文连通性有所提高。

Ecohydrological connectivity analysis of Gaoyou Lake wetland based on landscape indices

In order to quantitative evaluation the influence of water level change and human activity in the connectivity of the Gaoyou Lake wetland，the Comprehensive Ecohydrological Connectivity Index ( CECI) of Gaoyou Lake is built. The index based on the temporal and spatial changes of different landscape types of the wetland，used the interpreting data from Land satellite TM images and including CONNECT，COHESION，FN and DIVIDION indexes. The result shows that CECI can express the variation of ecohydrological connectivity of the Gaoyou Lake wetland quantitatively. With the increase of water level，the ecohydrological connectivity of Gaoyou Lake wetland improved gradually，and the CECI of lake landscape and river landscape increased from 2. 79，0 to 9. 21，6. 75 respectively. There was a high correlativity of ecohydrological connectivity variations of these two landscapes，and the ecohydrological connectivity of lake landscape is better than which of river landscape. From 2013 to 2017，the wetland hydrological connectivity improved and the area of Gaoyou Lake wetland increased because of human activities，such as return polder zone to lake and wetland. The CECI of lake landscape increased from 6. 27 to 7. 48，the CECI of river landscape increased from 2. 62 to 4. 61 with the same water level.