汶川地震区灾后植被恢复时空过程及特征——以都江堰龙溪河流域为例

定量评估地震区灾后植被恢复,对于灾区生态系统恢复重建及区域社会经济可持续发展规划具有重要科学意义.以都江堰龙溪河流域为案例区,采用MODIS-NDVI的时间序列数据,确定植被恢复评估的Landsat影像时间,并以Landsat影像定量揭示龙溪河流域植被在“5.12”汶川地震前后的动态变化;进而根据区域水系和地形因子,定量解析并揭示植被覆盖度受损恢复率的时空变化特征.结果表明:研究区植被覆盖受损恢复情况整体较好,但植被覆盖度对地震损害的响应存在滞后现象;受损植被恢复率与河流水系距离、海拔、坡度和坡向存在显著的相关性.本研究结果可为地震灾后植被恢复的决策干预提供技术支撑.

Spatial-temporal process and characteristics of vegetation recovery after Wenchuan earthquake: A case study in Longxi River basin of Dujiangyan,China.

Quantitative evaluation on the vegetation recovery after the earthquake is of great scienti-fic significance for local ecological system rebuilding and regional social-economic sustainable deve-lopment. By taking the Longxi River Basin in Dujiangyan of Sichuan Province as an example, and employing the MODIS-NDVI time-series data, this paper illustrated the dynamic changes of the ve-getation cover rates in Longxi River basin before and after the “5.12” Wenchuan Earthquake by using Landsat data, and then time-space characters of the recovery rates of the damaged vegetation was quantified structurally by referring the factors of river-system and terrain. The results showed that the recovery of impaired vegetation coverage worked well from a holistic point of view, but the response of vegetation coverage to earthquake disaster showed a lagging-phenomenon. The recovery rate of damaged vegetation was significantly correlated to its distance to surrounding river systems, elevation, slope degree, and slope aspect. This finding could provide technical supports for decision-makers to intervene the recovering process after earthquake.