全国山洪灾害防治县房屋损毁风险评估及原因探究

中国山洪灾害造成的经济损失在各类灾害损失中所占比重日趋增大,其中房屋损毁是造成经济损失和人员伤亡的重要因素。本文以房屋为研究对象,基于全国山洪灾害调查评价提供的数据,分析房屋暴露量的时空分布特征,构建山洪灾害房屋损毁风险评估模型,对房屋损毁风险进行分析及原因探究。结果表明：① 中国山洪灾害防治县以一层住宅为主,占比达50%以上的防治县分布范围大致与中国第二、三阶梯分界线一致;砖混结构仍为迄今为止中国山区农村运用最为广泛的房屋结构类型,其次为砖木结构,再次为钢混结构和其它结构;② 中国山洪灾害防治县房屋脆弱性呈现西北高、东南低的整体空间格局;房屋损毁风险呈现东部高、西部低的空间分布特征,且损毁风险较高的地区呈带状或集聚状态分布。损毁风险很高的地区集中于辽东半岛、山东半岛、海南岛及东南沿海地带,且在燕山-太行山区呈现沿东北-西南方向的条带状分布,损毁风险较高的地区主要分布于太行山区及长江中下游地区;③ 房屋类型对山洪灾害房屋损毁风险贡献度较高的地区主要为山东省、山西省及河北省;山洪强度对房屋损毁风险贡献率较高的地区主要呈3条条带状分布：燕山-太行山分布带、浙闽滨海丘陵分布带、两广滨海分布带。

Reasons and Risk Assessment of Housing Damage in the National Mountain Torrent Disaster Prevention County

The economic losses caused by torrential disaster in China are increasing. Housing damage plays an important role in economic losses and casualties. Based on the data provided by the survey and evaluation of torrent disaster, we analyzed the temporal and spatial distribution features of house exposure, constructed the damage risk assessment model of torrent disaster, analyzed the causes of housing damage risk and explored the reasons. The results showed that: (1) The houses in China rural area are mainly one-layer building, and distribution of one-layer dominated county is roughly the same with the boundary of the third terrain ladder of China; brick-concrete structure is the main housing structure in mountainous rural areas, followed with brick-wood structure, steel-concrete structure and other structures are the least. (2) Overall, the housing vulnerability is high in the northwest and low in the southeast, while the housing damage risk is high in the east and low in the west. The areas with extremely high damage risk are concentrated in the Liaodong Peninsula, Shandong Peninsula, Hainan Island and the Southeastern coastal areas and Yanshan-Taihang Mountains. The areas with high damage risk are banded or agglomerated, which are mainly distributed in the Taihang Mountains and middle-lower reaches of Yangtze River. (3) The high housing damage risk in Shandong, Shanxi and Hebei province are more relied on housing structure types. The houses with high damage risk which are mainly due to torrent strength are located within three stripes: Yanshan-Taihang Mountains Belt, Zhejiang-Fujian Coastal Hilly Belt, Guangdong-Guangxi Coastal Belt.