基于遥感影像的区域景观变化及生态风险评价

Regional Landscape Change and Ecological Risk Assessment Based on Remote Sensing Images

区域景观变化及生态风险评价研究对区域生态安全的监测、维护和保障具有重要意义。因此利用ENVI5.3和ArcGIS10.2系统,对河北衡水湖国家级自然保护区1985-2020年8期Landsat卫星遥感影像资料进行区域景观变化分析,结果表明:衡水湖保护区生态系统类型主要包括耕地、水域、未利用土地、沼泽和建筑用地,共5种。其中耕地和水域分别为第一和第二大生态系统。1985-2020年间,衡水湖保护区内景观变化显著,主要表现为耕地和水域面积明显增加,未利用土地面积大幅减少,沼泽和建筑用地面积变化不大。35年来,各类型之间发生了一定程度的相互转移变化:未利用土地向耕地转移是第一大转移方式,未利用土地向沼泽和水域转移、耕地和沼泽向水域转移是主要转移方式;建筑用地和沼泽面积虽然变化不大,但是35年间也各自经历着和其他4种类型间的相互转移。根据引入的生态风险评估模型,对衡水湖国家自然保护区进行了生态风险评估,结果表明,衡水湖保护区景观生态风险总体上处于中、低位状态,但是,近10年来生态风险有增加趋势,应引起重视。

The study of regional landscape change and ecological risk assessment is of great significance to the monitoring,maintenance and guarantee of regional ecological security.In this study,ENVI5.3 and ArcGIS10.2 systems were used to analyze regional landscape change of Hengshui Lake National Nature Reserve in Hebei Province from 1985 to 2020 based on 8 Landsat remote sensing images.The results show that there are five ecosystem types in Hengshui Lake reserve,including farmland,water area,unused land,marsh and building land,of which farmland and water area are the first and second largest ecosystems respectively.From 1985 to 2020,the landscape of Hengshui Lake Reserve has changed significantly,mainly manifested as follows:The areas of farmland and water have been enlarged significantly,the unused land area has decreased by a large degree,and the marsh and building land have not changed much.In the past 35 years,there has been mutual transformation somewhat amid these types.The transformation from unused land to farmland is the first major variation mode.Besides,the transformation from unused land to marsh and water area,and from farmland and marsh to water area are also the major modes.Although there is not so clear change in the area of building land and marsh,they have also experienced mutual transformation with the other four modes during the 35 years.The dynamic assessment of ecological risk shows that the landscape ecological risk of Hengshui Lake Nature Reserve is in the middle and low level on the whole,but the ecological risk has been increasing in the last ten years,so it needs the high attention from relevant parties.