【摘要】 本文以地震极重灾区2006、2008和2011年3期Landsat TM遥感影像为数据源,利用GIS提取灾区土地利用信息,结合坡度和高程等地形因子对灾区主要生态系统面积的变化进行综合分析。结果表明:2008年地震对灾区生态环境造成严重破坏,使研究区农田、森林和草地生态系统分别减少了124.6km2、461.6km2和92.3km2,其中,农田在北川、青川和平武的面积减少量最大,汶川森林面积减少了285.5km2;各生态系统在不同的高程和坡度下受地震影响程度存在很大差异;至2011年,灾区受损生态环境受自然演替和人工修复干扰影响,农田、森林和草地生态系统有所恢复,面积分别增加了82.8km2、58.3km2和174.9km2,其中,草地面积增加量超过受地震破坏损失量,但灾区生态系统整体恢复效果不理想,还需要采取进一步的生态恢复措施。更多还原

【Abstract】 Wenchuan Earthquake caused great damage to the ecological environment in the disaster-stricken area.In order to know the current recovery of the ecological environment damaged by the earthquake and provide data support for relevant researchers and decision makers,this paper took Landsat TM remote sensing images of June or July during 2006,2008 and 2011 of Wenchuan earthquake disaster-stricken area as data sources,used computerized and artificial visual interpretation method to extract the land uses information of the study area,and combined topographic factors such as elevation and slope to comprehensively analyze the reasons of the change of major ecosystems(farmland,forest and grassland).The results showed that the earthquake damaged the ecosystem of the study area seriously,resulting in substantial shrinking of farmland,forest and grassland by 124.6km2,461.6km2 and 92.3km2 respectively in the study area,and the farmland ecosystem had the most serious loss in Beichuan,Qingchuan and Pingwu counties,while the forest ecosystem lost 285.5km2 in Wenchuan County.The degree of influence on each ecosystem also varies a lot according to different altitudes and slopes.Up to the 2011,the status of the damaged ecosystem had got better in the study area through natural succession and artificial restoration intervention.Farmland,forest and grassland ecosystems had experienced certain degree of recovery,their areas increased 82.8km2,58.3km2 and 174.9km2 respectively.The recovery of farmland and forest ecosystems is not satisfactory while the area of grassland ecosystem had got the most increase,in 2011 which had exceeded the reduced area damaged by the earthquake in 2008,whereas the whole recovery of the ecosystems in research area was not ideal.Further measures of ecological recovery are thus in dire need of.更多还原