典型区生态系统格局长时间序列监测与评价

Long Time Serial Monitoring and Evaluation of Ecosystem Pattern in Typical Areas

基于Landsat TM/ETM遥感影像,综合分析我国易发生山洪和泥石流的典型区域。按照生态系统分类体系提取1985年、2000年和2013年岷江上游、白龙江上游、赣江上游和闽江上游流域生态系统分类信息,构建指标体系和计算模型,评价生态系统格局及变化。结果显示:2013年岷江上游和白龙江上游流域以森林和草地两种生态系统类型为主,分别占各自区域总面积的84.9%和83.1%;赣江上游和闽江上游流域以森林和耕地两种生态系统类型为主,分别占各自区域总面积的92.6%和93.6%。通过综合分析斑块数、平均斑块面积、边缘密度、聚集度指数变化,1985—2013年岷江上游流域整体景观破碎化趋势明显,景观类型分布更为分散;白龙江上游流域各景观类型分布趋向于聚集;赣江上游流域整体景观破碎度减小,景观类型分布更为集中;闽江上游流域整体景观破碎化趋势明显,人工表面景观格局破碎化程度减小。研究结果为优化区域生态格局、预防山洪和泥石流灾害提供参考。

Typical areas of flash floods and mudslides disaster in China were analyzed based on Landsat TM/ETM remote sensing images.The ecosystem classification information in the year of 1985,2000 and 2013 was extracted according to the ecosystem classification system in the upper reaches of Minjiang River(Sichuan Province),Bailong River,Ganjiang River and Minjiang River(Fujian Province).Then the ecosystem pattern and its change were evaluated by constructing index system and model.The results showed that the upper reaches of Minjiang River(Sichuan Province)and Bailong River were dominated by the ecosystem pattern of forest and grassland in 2013,accounted for 84.9%and 83.1%of the total area,respectively.While the upper reaches of Ganjiang River and Minjiang River(Fujian Province)were dominated by the ecosystem pattern of forest and cultivated land,accounted for 92.6%and 93.6%of the total area,respectively.As observed from the comprehensive analysis of the pattern changes from 1985 to 2013 by patch number,mean patch area,edge density and contagion index,the overall landscape fragmentation trend was obvious and the distribution of landscape types was more scattered in the upper reaches of Minjiang River(Sichuan Province),while the distribution of landscape types tended to gather in the upper reaches of Bailong River.The overall landscape fragmentation was de⁃creased and the distribution of landscape types was more concentrated in the upper reaches of Ganjiang River,while the fragmenta⁃tion trend of the overall landscape in the upper reaches of Minjiang River(Fujian Province)was obvious but with a decreasing frag⁃mentation degree for the artificial surface landscape pattern.These results provide a reference for optimization of regional ecological pattern and prevention of flash floods and debris flow disasters.