【摘要】 汶川8级大地震对地表产生强烈扰动,导致次生山地灾害极度发育,影响到震后灾害的活动特征及其相应的减灾对策。震后松散固体物质急剧增加、流域微地貌变化明显(沟道堵塞严重)、水文变化利于侵蚀和洪峰,使得灾害群发链生:崩塌、滑坡→泥石流→堰塞湖→溃决洪水(泥石流),8月中旬灾区各地因强降雨而大规模爆发泥石流堵塞河道,洪水冲毁掩埋重建城镇,给地震重灾区造成巨大损失。从以汶川县映秀镇为例,在阐述灾害链研究成果的基础上,分析震后灾害链的形成条件、成灾过程以及对城镇重建居民点的危害特点,进而提出灾害防治措施,为灾后城镇建设防灾减灾提供参考建议。更多还原

【Abstract】 The Wenchuan earthquake produced strong disturbance to ground surface,which caused extreme development of secondary mountain disasters and influenced the activity characteristics of seismic disasters and disaster countermeasures.After the earthquake,loose mass in the gully channel was increased rapidly,micro-topography was changed significantly and hydrological changes were favorable to erosion and flood.Thus the disaster chain as collapse,landslide,debris flow,dammed lake and outburst flood occurred frequently.Large-scale debris flows due to torrential rains in mid August of 2008 dammed river courses and flood damaged and buried the towns under reconstruction in different disaster areas and caused great loss to heavily hit areas of earthquake.In this paper,taking Yingxiu town of Wenchuan as an example,the results of research on disaster chain are described and formative conditions of post-earthquake disaster chains,disaster development process and characters of damages to urban residential areas under reconstruction are analyzed.Moreover,disaster preventive measures are put foreword which are of referential value to disaster prevention and mitigation in post-disaster urban reconstruction.更多还原