基于两步移动搜寻法的居民应急避难场所可达性分析——以北京西部城区为例

从空间可达性角度研究其应急避难场所布局的合理性具有非常重要的战略意义和现实意义。本文采用基于GIS的两步移动搜寻法,以北京市海淀、丰台、石景山3个西部城区的59个街道为研究单元区,分析不同服务距离(阈值)下可达性的变化,并对现有避难场所的服务功能做出评价。结果表明:(1)海淀、丰台、石景山三城区均处于较低的应急避难服务水平。(2)3个城区应急避难场所空间分布不均,其中海淀区的应急避难场所相对较多,空间分布相对较为均匀。(3)各街道间拥有的避难资源空间差异明显,海淀街道相对富裕,丰台区宛平城地区以西则严重匮乏。

Examining Accessibility to Resident Emergency Shelter Based on Two-steps Floating Catchment Area Method: A Case Study of Western Beijing

City emergency shelters can provide people to avoid disasters such as city fire,explosion,flood and earthquake.It is generally possible to assess whether the emergency shelters are rational by accessibility.By using the two-steps floating catchment area method based on GIS platform,this paper takes 59 streets in Haidian,Fengtai and Shijingshan as the research unit area.It analyzes the changes of accessibility when the service distances (threshold) are 2000m,3000m and 5000m.At the meantime,the research also evaluates service and function of the existing emergency shelters in the above three districts.The results show that,(1) The three districts of Haidian,Fengtai,Shijingshan are all at the low emergency evacuation service level.(2)The spatial distributions of the emergency shelters in all the three urban districts are unequal,among which there are more emergency shelters in Haidian district,and as well the emergency shelter distribution of Haidian district is better than the other two.(3) The differences among all the streets unit are obvious.Haidian Street owns much richer ones,while the emergency shelter is insufficient in the most street districts,especially in the west of Fengtai Wanping area.