中国农村房屋震灾脆弱性评估及其成因分析

中国农村地区的房屋普遍处于地震未设防的状态,在地震中房屋结构破坏是造成人员伤亡和财产损失的主要因素。作为重要的灾害承险体之一,从房屋结构方面进行区域震灾损失的预测对把握各个地区的灾害脆弱性,科学地制定区域防灾战略和规划具有极其重要的意义。①基于中国县级尺度房屋结构数据库的前期基础工作,以2000 年中国地震区划为基本依据,参考震灾条件下的不同结构房屋破坏比和易损性曲线的研究成果,对中国县级空间尺度的农村房屋震灾脆弱性进行了整体评估。② 根据房屋破坏损失的预测结果,将中国农村地区划分为低脆弱性、一般脆弱性、较高脆弱性和极高脆弱性地区4 类,并对较高、极高脆弱性地区的空间分布规律进行了分析。结果表明,中国约18.6%的县处于脆弱性较高和极高的地区,主要集聚在南疆,北疆的乌苏、精河、伊宁等地区,陕西、甘肃、宁夏地区,山东中南部、安徽、江苏等地区,西藏南部边境地区,云南以及青藏高原板块边缘纵贯青川滇的都兰—玛多—道孚—泸定—冕宁—昆明—建水沿线地区。③ 根据各个地区震灾脆弱性的成因和类型,以及较高、很高脆弱性地区的区域发展水平特征,提出了区域防灾策略的建议。

Seismic Vulnerability of Rural Housing and Regional Anti-disaster Strategies in China

In China,more than 80% of the total loss of seismic disasters happened in ruralareas.In particular,damages of rural housing have been the main cause of casualties andproperty losses.This study evaluated the seismic vulnerability of counties in terms of thestructure of rural houses,based on the share of different building structures including wood,brick,mix,reinforced concrete,the earthquake intensity zoning of China,and probabilities ofbuilding damage by structures.With a comprehensive damage index made up of damageamount and damage ratio,all the counties are classified into four vulnerability levels:low,medium,high,and extremely high.Then the influencing factors of vulnerabilities and theirspatial differentiations are explored,including those of building structure,earthquake intensityand population density.Accordingly,suggestions are made for anti-disaster strategies indifferent areas.