汶川震后植被恢复趋势与地形关系研究

Study on the Relationship Between Vegetation Restoration Trend and Terrain after the Wenchuan Earthquake

汶川地震造成震区植被损毁严重.震后自然植被恢复情况评估,对地震灾区恢复重建和规划有重要意义.选择都江堰-映秀草坡区为研究区,计算不同时相的归一化植被指数,分析震后研究区植被覆盖变化和植被恢复状况.提取受地震影响植被指数负变化区域,分析该区域2009年至2014年植被恢复度同地形因子的时空分布关系.分析表明:震后植被总体恢复较好,但研究区植被恢复情况不均匀.植被恢复度增长趋势随着坡度的增加表现为先增长,当植被恢复度达到0.6时,植被恢复度增长趋势随着坡度的增加而减少;植被恢复度增长趋势随着高程的增加表现为先增长,当植被恢复度达到0.45时,植被恢复度增长趋随着高程的增加而减少.

Assessing vegetation restoration has important significance on reconstruction and restoration planning of earthquake -stricken area.The normalized difference vegetation index is calculated to analyze the change of vegetation coverage and vegetation restoration condition.Negative change region of vegetation index is extracted to analyze the relationship between vegetation restoration and terrain factors.The analysis shows that the total recovery of the vegetation was good,but the vegetation recovery was not uniform in the study area.The growth trend of vegetation recovery increased with the increase of slope.When the degree of vegetation restoration reached 0. 6,the growth trend of vegetation recovery decreased with the increase of slope.The growth trend of vegetation recovery increased with the increase of elevation.When the degree of vegetation restoration reached 0.45,the growth trend of vegetation recovery decreased with the increase of elevation.