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Abstract A landslide occurred on July 7th 2007 in Yanmen village of Daxian County，Sichuan Province，and it caused economic loss of about RMB 0.15 billion. The information of the geological environment of the Yanmen slope，the displacement of roads，pools and tree groups，and the elevation variety before and after the landslide occurrence had been captured using high resolution satellite image with digital landslide technique. Based on the deformation characteristics the slope is divided into 4 regions：main sliding region，retrogressive sliding region，intensive influence region and influence region；and their moving styles are considered as quick push+sand soil liquefaction and flow in plane manner at the front part，retrogressive sliding，tension cracks，deformation and partial displacement caused by tension force，small cracks and deformation caused by land shake. With DEM，the volume of mass of sliding out and deposit from ground before landslide were estimated as 132.6×104 and 132.2×104 m3 respectively；and combining with drilling data，the landslide volume from sliding surface is estimated as 1.97×106 m3. The lithology and geological structure conditions for Yanmen village slope are feasible for forming a landslide but it is difficult to form large-scale and thick ones since it faces a small and narrow valley which is suitable for developing partial and shallow landslides. Long-term and intensive rainfall was the main inducing factor for forming Yanmen village landslide. As for whole slope，the movement of landslide occurred on July 7th，2007 had not release energy sufficiently，therefore，in conditions of continuous rainfall，landslides may occur in parts of the slope but it is hard to have the large-scale landslide of whole slope.
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Received: 09 February 2009
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