都江堰龙池地区泥石流滑坡体遥感动态演变特征

"5.12" Wenchuan Earthquake produced abundant debris left behind on the hillside slopes, when encountering heavy rains, it will generate debris flow. On 13th October 2010, a total of 48 debris flows were triggered by heavy rainfall in the central part of the epicenter region affected by the Wenchuan Earthquake. 12 debris flows of Longchi Dujiangyan County in the central epicenter region are chosen for analyzing the change of debris flow source area before and after the earthquake and also following a rainstorm. Significant differences after the earthquake and rainstorm are noticed in producing a large amount of landslides for debris flow occurrence. Through the remote sensing interpretation, combining with field investigation, this paper expounds debris flow source activity in the studied area. Comparison of the TM images taken on 18th September 2007 (before the "5.12"Wenchuan earthquake) with the SPOT5 images taken on 10th February 2009 (after the "5.12"Wenchuan earthquake) indicates that the landslide area in 12 debris flow watersheds increases from 0.86×106m3 to 42.30×106m3 during that period of time, which means landslide volume increases 4835.94% after Wenchuan earthquake. Comparison of the SPOT5 images taken on 10th February 2009 (after t the "5.12"Wenchuan earthquake) with the WorldView-2 images taken on 14th July 2011 (after the"8.13"rainstorm event) indicates that the landslide area in 12 debris flow watersheds increases from 42.30×106m3 to 68.85×106m3 during that period of time, which means landslide volume increases 62.76 % after rainstorm.)