城市局域动态人口估算方法与模拟应用

获取城市局部区域内的实时人口是应急决策等诸多城市管理应用需要解决的问题。但时空的不确定性导致了估算操作的困难:空间范围不确定,即给定的城市区域是可变的;时间不确定,即估计的时间事先不可知。根据城市居民的总体出行规律,居民日常活动基本以城市建筑为中心,或者认为居民因受建筑物所承载功能的吸引而出行。鉴此,给定区域内的静态人口可使用区域内的居住型建筑,以及人均住房建筑面积等统计数据来估算,而动态人口的估算则需要确定每类建筑物在不同时刻所吸引的居民人数。为此,引入建筑物修正系数和建筑物吸引率两个指数。修正系数是其他类型建筑物的容纳能力与作为基准的居住型建筑物的容纳能力之比。通过修正系数可获得每类建筑物的额定容纳人数。吸引率是不同时刻每类建筑物的实际容纳人数与其额定容纳人数的比值。根据居民出行的一般时间分布,将一天按照休息日和节假日分别都划分成七个时段,建筑物类型参照调查城市交通出行率时的分类划分。利用居民出行和交通出行率调查资料等数据,估算每类建筑物的修正系数和吸引率,计算区域内的实时人口数,模拟了一起突发化学品泄漏事故,将所提方法应用到模拟场景的动态人口估计中,并对方法应用中的问题进行了讨论。

An Estimation Method of Dynamic Population within an Urban Local Area

A problem involved in emergency decision-making and many city management works is to evaluate the population within some given urban areas at a random time.The unknown spatial areas and evaluation time which constitute two fundamental uncertainty features of the problem bring great difficulty for its solution.Following the overall disciplines presented in daily traveling of urban residents,we know that people basically arrange their activities around various city buildings.Another explanation for the phenomenon is residents travel between buildings because they are attracted by the functions of them.So,in this paper,a method is developed to evaluate the static population inside a given area,which uses the data of buildings for habitation and average housing floorage per urban resident according to statistics.While another step must be done for assess the dynamic population,which is to confirm the population attracted by each type of building at any time.Two new indices are introduced： building correction coefficient and building attraction rate.The former refers to the ratio of average accommodated people between other building types and residential building.A rated accommodation people for each type of buildings can be achieved using the index.The latter is the ratio of real accommodation people to rated one.Here we divide the work day or break day all into seven periods according to the general time distribution of residents＇ traveling activities,and confirm a building type category by reference to one used in the occurrence rate investigation of city transportation.The two indices are estimated using the traveling investigation data of residents and vehicles.Then the dynamic population is drawn based on the proposed method.A case of chemical emergency in Beijing is imagined to demonstrate the application of the method and the issues concerned with parameter fixing that is the key to the method is discussed.