基于多时相遥感数据的典型区生态格局变化分析

利用1985、2000、2013年遥感影像提取的土地覆盖数据,通过景观格局指数、动态度计算、转移矩阵等,分析1985—2013年我国典型地区各类型生态系统景观格局及其动态变化特征、生态系统相互转化时空变化特征等,揭示1985—2013年生态环境格局变化的特点和规律:一级分类生态系统综合变化率,赣江、闽江、白龙江和岷江上游流域分别为4.7%、3.9%、3.3%和1.7%,生态系统变化强度1985—2000年较缓,2000—2013年更剧烈。1985—2013年典型区生态系统的主要转化方向具有持续性和双向性特征,岷江、白龙江和赣江上游流域退耕还林还草政策效果明显,出现较高比例的耕地转为森林和草地;面积占67.4%生态系统类型变化与耕地生态系统和人工表面生态系统变化有关;生态系统变化具有明显的区域差异,生态变化主要表现为沿主要河流谷地的线状延伸,主要城镇居民点附近生态系统类型变化较为突出,人类活动是典型地区生态系统类型格局变化的主要驱动力;典型区尤其是敏感区应加大退耕还林还草政策,减少人类经济活动,降低洪水泥石流灾害发生的概率和程度。

Analysis of Ecological Pattern Changes in Typical Areas of China Based on Multitemporal Remote Sensing Data

Using the land cover data extracted from remote sensing images in 1985, 2000 and 2013, the landscape pattern and dynamic change characteristics of various types of ecosystems, and the temporal and spatial change characteristics of ecosystem mutual transformation in typical areas of China from 1985 to 2013 were analyzed by means of spatial distribution statistics, dynamic degree calculation, transfer matrix and landscape pattern index, to reveal the characteristics and rules of ecological environment pattern change from 1985 to 2013.From 1985 to 2013, the comprehensive change rate of ecosystem in the level 1 classification system of the typical areas was 4.7%, 3.9%, 3.3% and 1.7% in the upper reaches of Ganjiang River (Sichuan Province), Minjiang River, Bailong River and Minjiang River (Fujian Province) respectively, among which the change intensity of ecosystem was relatively slow from 1985 to 2000, and that was more intense from 2000 to 2013.The characteristics of the typical areas'' ecosystem main transformation direction were sustainability and interconvertibility, the upper reaches of Minjiang River(Sichuan Province), Bailong River and Ganjiang River were obviously affected by the policy of returning farmland to forest and grassland, and a high proportion of cultivated land turned into forest and grassland;the change of ecosystem had obvious regional differences, and the ecological change was linear extension along the river valley mainly, the change of ecosystem type near the main residential areas was more prominent;67.4% of the total area of ecosystem type change was related to the change of cultivated land ecosystem and artificial surface ecosystem from 1985 to 2013, so human economic activity was the main driving force for the change of ecosystem type spatial pattern.In order to reduce the frequency and degree of flood and debris flow disaster, the policy of returning farmland to forest and grassland should be increased, and reduce human economic activities in the typical areas, especially in sensitive areas.