论文部分内容阅读
为了评估汶川地震引发的崩塌、滑坡和坡面泥石流等次生灾害对地表植被的破坏状况,对四川汶川地区地震前2007年4月19日和地震后2008年5月23日同一季节的美国Landsat 7 ETM卫星遥感图像,经预处理后反演地表植被覆盖度信息,检测地震灾害引起的植被覆盖变化。结果表明,地震灾害引起的植被覆盖减少区域主要分布在陡峭的河流两岸和沟谷地形地区,崩塌、滑坡和坡面泥石流等引起的裸露地表增加的面积占研究区面积的比率近6%,研究区植被覆盖度减少的面积达到33.7%,占总面积的1/3,显著减少(植被覆盖度减少量超过0.2)的面积达到10.3%,地表植被受到大面积的破坏。
In order to assess the damage to the surface vegetation caused by the Wenchuan earthquake-induced collapse, landslides and debris flow on the slope surface, the impact of the surface vegetation on the Wenchuan earthquake in Sichuan Province on April 19, 2007 and the earthquake on May 23, 2008 in the same season, 7 ETM satellite remote sensing image, after pretreatment, the information of vegetation cover in the ground is retrieved and the change of vegetation cover caused by earthquake disaster is detected. The results show that the area of vegetation cover reduction caused by the earthquake disaster is mainly distributed in the steep river banks and valley topography. The area of bare land surface caused by landslides, landslides and slope debris flow increases nearly 6% of the area of the study area. The area of vegetation coverage decreased by 33.7%, accounting for 1/3 of the total area. The area of significant reduction (vegetation coverage reduction of more than 0.2) reached 10.3% and the surface vegetation was destroyed by large area.