基于景观格局的赣江上游区生态风险变化研究

A Research on Changes of Ecology Risk in the Upstream of the Ganjiang River based on Landscape Patterns

基于景观格局的生态风险变化分析是区域的生态风险管理的科学基础.本文选用区域综合风险分析模型,结合层次分析法、GIS技术和FRAGSTATS3.3软件,根据地球科学数据共享网1980s以来的土地利用数据,通过生态景观类型提取、综合生态风险指数和生态风险要素中的风险源、风险受体和风险效应计算,系统的分析赣江上游区80年代以来生态风险的时空变化特征及其驱动因素.结果表明在研究区的六种景观类型中,聚落景观增加明显(从0.90%增加到0.97%),林地、农业景观和水域占比在波动中略有增加,草地和其他景观呈下降趋势.综合生态风险指数分析显示研究区自1990s以来生态风险水平呈上升趋势.基于风险"三要素"的变化机制分析表明,赣江上游区风险源主要来源于农业景观和聚落景观的变化.人为因素是本区生态风险水平上升的最主要原因.

It is a scientific basis for regional ecological risk management to research into changes in ecological risk based on landscape patterns. This paper employed a regional synthesis risk analysis model,integrated with methods like analytic hierarchy process（ AHP）,GIS technology and FRAGSTATS3. 3 software,to analyze the temporal and spatial variation characteristic of ecological risk since 1980 s as well as their driving factors in the upstream of the Ganjiang River. The data were from Data-Sharing Network of Earth System Science including the land use GIS records in 1986,1995,2000 and 2005. We extracted the ecological landscape types,calculated and analyzed the risk elements such as the risk source,risk receptors and risk effects. The results show that of the six landscape types involved,the ratio of settlement landscape noticeably increased from 0. 90% in 1986 to 0. 97% in 2005. The ratios of landscapes such as forests,agricultures and waters have fluctuated to increase slightly. The ratio of grasslands and other landscapes have tended to decline. The comprehensive ecological risk indexes exhibit that the ecological risk levels in the region of interest have remarkably increased since 1990 s. The driving factor analysis from the three risk elements proclaims that the risk source in the upstream of the Ganjiang River were mainly from the agriculture landscape and settlement landscape,which implies human disturbances might be the key factor to explain the ascending tendency of ecological risk level.