“5·12”汶川特大地震灾害特点及其防灾启示

Damage Characteristics and Enlightenment of Disaster Prevention of "5.12" Wenchuan Earthquake

本文介绍了"5·12"汶川特大地震发生的构造背景、震源与余震分布特点,认为该地震是青藏高原巴颜喀拉块体东向运动并与四川盆地相互长期作用的结果,地震主要能量释放在长330km、宽52km、深20km的块体(震源体)内,能量释放时间长达100多秒。地震在震源体内释放的能量极其不均匀,地面运动在震中区也具有强烈的时间、空间不均匀性。高烈度区沿震源体分布,烈度分布具有明显异常特征。地震造成的人员死亡90%以上位于烈度Ⅸ度以上地区。居民建筑、学校和医院等建筑物遭受严重破坏,交通、水利等生命线也遭受重大破坏。地震引发的崩塌、滑坡和泥石流灾害十分严重。巨大的地震灾害暴露出防震减灾管理、地震科学研究、防震减灾技术研发应用,以及防震减灾宣传等方面的严重不足。

In this paper, the geological tectonic background, hypocenter mechanism and aftershock distribution of 5.12 Wenchuan earthquake are introduced. This earthquake is considered as the result of long time movement between Bayan Har Block to the east and Sichuan Basin, and the most energy of the earthquakes release from a block of 330km long, 52km wide, and 20km deep for over 100s. Releasing energy of earthquake hypocenter body is extremely uneven, and strong ground motion in the epicenter area is of strong asymmetric characteristic at both time and space scale. High-intensity area distributes along the hypocenter body, intensity distribution have obvious anomaly characteristics. The investigation results indicated that, more than 90 percent of the deaths caused by this earthquake are within above intensity IX area. Resident constructions, school buildings, hospitals, transportation system, water facility and lifelines suffered serious damage. On other hand, earthquake-triggered dilapidation, landslide, mud-rock flow and so on are also extremely serious. The big lesson learnt from this huge earthquake disaster is that we are in serious shortage of local disaster prevention and mitigation management, earthquake scientific research, technology and application for earthquake disaster prevention, and propaganda of earthquake prevention and disaster reduction etc.