【摘要】 为了研究汶川地震山地灾害灾害分布对环境因素的响应机制,通过对汶川地震灾区的调查和遥感解译,详细分析灾害分布特点,用GIS平台对4722个典型灾害点的环境因素进行分析,得出以下结论:1)地震能量释放的长短轴效应造成地震能量主要沿断裂带释放,灾害点沿中央断裂呈条带状分布,在距中央断裂20km范围内集中灾害总数的64.42%,逆冲断裂的上下盘效应使上盘灾害发育程度明显高于下盘和下盘灾害密度经历先降低后升高再降低的变化;2)灾害点在山地地区集中分布在河谷两岸,河谷岸坡对地震的放大作用使坡体上部岩土首先崩解,带动坡体下部的岩土一起运动,形成"山剥皮"特点的崩滑型灾害;3)灾害总数的99.43%集中分布在地震烈度Ⅶ度及其以上地区,地震的场地效应使灾害在易滑岩层中较为发育;4)在区域地势变化与地震断裂破裂一致的方向上有利于地震能量的传播,灾害更容易发生,规模较大的滑坡主滑方向也大多数发生在两者的并集方向。更多还原

【Abstract】 For revealing the relationship between the distribution of landslides and environmental factors,4722 earthquake-induced landslides were studied with field investigation and the interpretation of remote-sensing images.GIS technique was used to finish the statistical data including distance from middle faults,lithology,altitute,river,slope and aspect of slope.The results about the responsive mechanism between the distribution of landslides and environmental factors were summarized as follows.The zonal distribution of landslides was consistent with the strike of middle faults and the seismic energy was released along the middle faults which caused the attenuation of energy obvious in minor axis and about 64.42% of landslides were distributed within 20 km from middle faults.The density in hangingwall of middle faults was obviously higher than that in footwall which underwent the variation of reduce-increase-reduce because of the break of middle and front thrusting faults.The release of seismic energy was restricted by landform and river.The high density of landslides was in high altitude,steep slope,intense incision.The concentrated distribution of landslides was in river banks and the origin of landslides was in upside of slope because of the magnified effect for earthquake.About 99.43% of landslides were distributed in area where the seismic intensity was more than Ⅶ and the highest density of landslides were in soft rocks because of the earthquake site coefficients.The high density occurred in the intersection direction of the gradient topography and the faults breaking and landslides with large scale appeared in the union direction,which was convenient for seismic energy transmitting.更多还原