四川宣汉特大型滑坡特征及形成机制分析

2004年9月5日四川省宣汉县天台乡发生了震惊中外的特大型滑坡，滑坡摧毁了一个自然村并严重堵塞河道，形成库容5 800万m³的一座滑坡堰塞湖，淹没上游的五宝镇及沿河8个村庄，致使19 360人失去家园，造成直接经济损失约2亿元，特别严重的灾情一度成为中央领导及中外新闻媒体关注的焦点。天台滑坡面积达1.2km²，总体积2 500×10⁴m³，河道中堆积物210×10⁴m³，属特大型后退式岩质滑坡，是300年一遇特大暴雨诱发的自然地质灾害，是四川盆地红层丘陵区发生的规模最大、财产损失巨大的特大型滑坡灾害。由于预报及时、群测群防措施得当、抢险救灾组织有力，该滑坡没有造成任何人员伤亡，创造了四川省地质灾害减灾防灾的一个奇迹。

Forming Mechanism Analysis and Characteristic of Especial-huge Rock Landslide at Tiantai Village of Xuanhan County in Sichuan Province

Huge landslide which had astounded China and foreign countries had taken place in Tiantai countryside of Xuanhan county in Sichuan Province on Sept.5, in 2004.The landslide destroyed a village, jammed a river way, formed a barrier lake which had 58×10⁶ m³ in reservoir cubage and flooded upriver Wubao town and 8 villages along the river, resulted in losing homes for 19.36 thousands peoples and economic damage of 200 million yuan. Tiantai landslide which is 1.2 km² in acreage, 2500×10⁴ m³ in all cubage, has 210×10⁴ m³ accumulations in river way and belongs to especial-huge and retrograde style rock landslide, is a national geological disaster which has been induced by huge rainstorm in 300 years and is an oversize landslide disaster which scope and possession losing is the largest at the red stratum in Sichuan basin. The landslide had not made any casualty because of forecasting betimes, measuring suitable and advantageous organizing. The landslide governance had created a miracle of decreasing and preventing geological disaster in Sichuan Province.