四川省汶川地震极重灾区次生山地灾害分布规律与发育趋势

通过对汶川地震极重灾区次生山地灾害的实地考察、遥感调查和综合分析,阐述了次生山地灾害类型与特征,分析了次生山地灾害的时空分布规律,并结合灾害活动特性,探讨了次生山地灾害的发育趋势,提出了灾区防灾减灾和恢复重建的对策与建议。研究结果表明:(1)汶川地震在极重灾区诱发次生山地灾害逾万处,其分布具有点多面广、类型多样、成灾迅速、危害严重、监测预报困难等特点;(2)次生山地灾害的分布受地震烈度、地质构造、地形地貌、地层岩性的制约,并具有明显的滞后性和延续性;(3)利用GIS和遥感技术,能够快速有效地进行地震次生山地灾害的动态监测与灾情评估,从而为防灾减灾管理和灾后重建工作提供科学依据和借鉴参考。

Distribution and development of secondary mountain hazards induced by the May 12,2008 Wenchuan Earthquake in the ten most severely-afflicted counties

Based on the field investigation,remote-sensing investigation and comprehensive analysis of secondary mountain hazards induced by the Wenchuan Earthquake,the paper took the ten most severely-afflicted counties as a pilot site,discussed the types and features of secondary mountain hazards and explained the spatio-temporal distribution law of secondary hazards.In view of the above,the development of secondary hazards was probed and the suggestions of disaster-prevention and mitigation suggestion were given according to the disaster action features.The findings show that： a） Secondary mountain hazards triggered by Wenchuan Earthquake occur more than 10 000 sites and scatter widely in the study areas with the features of various types,rapid occurrence,large scale,serious damage and diffculties in monitoring and forecasting;b） the distribution of secondary hazards is dominated by geologic structure,topography,physiognomy and lithology as well as the development of secondary hazards with significant lay and continuity;c） secondary mountain hazards can be effectively monitored and assessed by means of the technologies of geographical information system（GIS） and remote sensing（RS）.The findings of this paper can be used as a scientific basis for preventing and mitigating secondary mountain hazards and making reconstruction of the afflicted areas.