基于脆弱性曲线的河北省日光温室大风灾害风险评估

Risk assessment of wind disaster to greenhouse in Hebei province based on vulnerability curves

基于灾害风险评估理论,利用极值概率分布模式,结合致灾因子和承灾体内在属性,构建大风风速-日光温室损失率脆弱性曲线,对河北省大风灾害日光温室受损风险进行定量评估。研究表明,随重现期的增加,风灾危险性及日光温室灾损风险的强度和范围也增加。空间上,地势低平的东南部风灾危险性最高,主要位于沧州东部、衡水北部和邯郸东部,日极大风速超过32.6 m/s。基本风压与三大地貌的分布呈现一致,高值出现在西北高原区和太行以东-燕山以南的平原区,太行-燕山山区较小。脆弱性曲线表明日光温室开始出现损失的临界风速值为20.0 m/s。温室受损风险受致灾因子和承灾体共同作用,总体呈现西北低东南高,高风险区分布在唐山-秦皇岛交界、唐山西部、廊坊及中南部地区,地均损失超过50万元/km^2。中南部的温室面积小于东北部,但其致灾因子危险性较高,损失风险也较高。

Based on the disaster risk assessment theory and climate probability distribution model, the wind disaster risk to greenhouse in Hebei province was evaluated. The vulnerability curves of wind speed -solar greenhouse loss rate were constructed, considering disaster-causing factor and bearing body. The results showed that, with the increase of return periods,the strength and incidence of hazard factor and loss risk was greater. In terms of space, the southeastern area with low terrain had the highest hazard factor risk, mainly located in the eastern part of Cangzhou, as well as the northern Hengshui and eastern Handan. The extreme wind velocity was above 32.6 m/s. The basic wind pressure was consistent with the landforms’ distribution. The basic wind pressure was consistent with the distribution of the three landforms, with the high value occurring in the northwest plateau area and the plain area to the east of Taihang and the south of Yanshan Mountain areas.The vulnerability curve indicated that the threshold of wind speed which might cause loss to greenhouse was 20.0 m/s. The risk of greenhouse loss was affected by the combined effects of disaster-causing factor and bearing body. The risk in the northwest was generally lower than the southeast. The high-risk area was distributed in the junction of Tangshan-Qinhuangdao, western Tangshan, Langfang and south-central regions. The average loss was more than 500 000 yuan/km^2. The greenhouse area in the south-central part was smaller than that in the northeast, but the loss was higher owing to its higher hazard factor risk.