2013年北川聚落空间的地质灾害灾情分析

Analysis on the Geological Disasters Occurred in the Settlements Space in 2013 for the Beichuan Qiang Autonomous County

北川羌族自治县是2008年汶川8.0级地震的极重灾区之一。2013年7月8-12日,北川县境内普降暴雨,引起地质灾害事件大面积爆发。洪灾之后的灾情普查数据表明,县域内共有1 318个居民点受到各类地质灾害的威胁,这些地质灾害点的类型多样、分布广泛并且所造成的危害严重。根据灾情普查数据,按乡镇单元提取了各自的灾害点数量、受威胁面积、受威胁户数、受威胁人数、受威胁财产以及防治费用等6个指标,采用主成分分析方法来进行地质灾害灾情的综合评价,根据各乡镇的综合得分对乡镇的灾情进行了排序。这个评价结果较好地反映了各乡镇之间的灾情差异,也为上一级政府进行诸如制定乡镇社会经济发展指标、决定防灾减灾资金及技术力量的投向等行政决策提供了直接依据。

Beichuan Qiang Autonomous County was one of the hardest destroyed areas in the 2008 Wenchuan earthquake.Many geological disasters occurred in the settlement space because of the heavy rainfall which lasted from the July 8 to 1 2 in 201 3 .The results of the field survey after the storm showed that there were about 1 31 8 set-tlements hurt by geological disasters,and these different kinds of geological disasters were widely distributed in the county with heavy threatens.There are 23 towns in the Beichuan County;the geological disaster states are quite different among these towns.In order to evaluate the disaster state of these towns,six indexes of each town and the principal component analysis method are employed.The indexes include the numbers of the disasters,the area threaten by the disaster,the population threaten by the disaster,the family numbers threaten by the disaster,the property threaten by the disaster,and the disaster prevention costs.The evaluation result can tell the difference of the disaster state among the towns definitely,and it can be act as the administrative policy basis of the disaster management.