创意产业及其地方性

本文致力研究创意产业集群与城市政策和效益之间的互动。研究的创意产业行业包括软件、多媒体、电子游戏、时装设计、出版、研究与开发。经验调查研究以多个城市的情况作为基础,这些城市包括美国的波士顿、旧金山、圣迭亚戈、西雅图、奥斯丁、华盛顿特区、爱尔兰的都柏林、东京和印度的班加罗尔。本文关键的研究问题是:什么类型的城市是富有创意的?什么区位因素是必不可少的?创意城市共同采取的政策措施有哪些?文章首先总结了影响地方特定创意产业集群的因素和政策措施;接着深入剖析两个成功的创意城市——波士顿和圣迭亚戈的案例,随后讨论城市各自的某些特征是否使得它们更适合发展某一特定的创意产业。     

ETHNIC NEIGHBORHOODS AND URBAN REVITALIZATION: CAN EUROPE USE THE AMERICAN MODEL?

ABSTRACT. Ethnic neighborhoods have long been used to facilitate urban revitalization in older, inner‐city neighborhoods in American cities, but this strategy is much less common in European cities. This is especially surprising because immigrants make up a significant percentage of the population in a large number of those cities. This article explores the role that a largely invented Little Italy has played in revitalizing a section of downtown San Diego in contrast to the difficulty of creating such districts in European cities. The question posed here is, Will this contrast in approaches and outcomes remain indefinitely, or will the use of ethnically themed revitalization strategies become more alike as globalization and the expansion of the European Union serve to lessen historic ethnic tensions and increase the number of distinctive immigrant districts in Europe?     

Biogeography: Introduction to Space,Time, and Life

Glen MacDonald. New York: John Wiley and Sons, Inc. 2003. x and 518 pp., maps, diags., photos., glossary, and index. $86.95 cloth (ISBN 0‐471‐24193‐8). Reviewed by Janet Franklin, Department of Biology, San Diego State University, San Diego, CA.     

Locating day-labor employment: toward a geographic understanding of day-labor hiring site locations in the San Diego metropolitan area

Day-labor hiring sites are common features of the contemporary North American landscape. These are public and semi-public spaces where mostly male residents congregate daily in hopes of being hired for short-term work. Research on contemporary day-labor markets in the United States to date tends to be policy-oriented, intended to reduce the injustices that are a common part of life as a day laborer. Unfortunately, very little is understood about the spatial organization of day-labor markets. Drawing on more than five years of mixed-methods research in the San Diego Metropolitan Area (SDMA), this paper takes two important steps toward a spatial understanding of day-labor hiring sites. First, it demonstrates that informal hiring sites are established in locations that maximize laborers’ chances of finding employment. Second, it establishes a geo-spatial typology of hiring sites for the SDMA that can be used to better tailor day-labor support efforts and policy to site-level context.     

基于出行链的建成环境对居民小汽车通勤出行的影响

城市建成环境对居民出行,尤其是小汽车通勤出行的影响是交通需求预测的基础性命题,长期受到关注.已有研究大多以单次出行作为研究对象,较少关注出行链影响下的出行协同决策问题.论文基于2017年广州市居民活动日志调查数据,采用Logistic模型检验了出行链视角下城市建成环境对工作日选择小汽车通勤出行的影响.研究发现,出行链中...     

Integrating Fire Behavior and Pedestrian Mobility Models to Assess Potential Risk to Humans from Wildfires Within the U.S.–Mexico Border Zone∗

Wildfires create a risk to pedestrians traveling through rural areas, because they might not be aware of the presence of a wildfire or its direction and rate of spread until is too late to successfully evacuate. In wildland areas of southern San Diego County, immigrants crossing the U.S.–Mexico border and border security agents are particularly at risk to wildfires. The objective of this study is to develop a framework of analysis and associated tools for examining the combined behavior of wildfires and pedestrian mobility to assess the potential threat of fire to pedestrians in wildland areas. Outputs from a geographic information system (GIS) overlay model for determining potentially dangerous fire zones, the Wildland–Urban Interface Evacuation (WUIVAC) model, and a model of pedestrian mobility in wildland areas were combined to generate wildfire risk to pedestrian maps. The key technical contributions of the study are the development and testing of the pedestrian mobility model and the framework and logic for integrating the results of three GIS-based models. The applied geography contribution is the testing of two scenarios of high risk from wildfires to pedestrians within the U.S.–Mexico border zone of San Diego County, California.

The study results show that the travel times calculated by the pedestrian mobility model appear to be realistic and are affected by the terrain and vegetation characteristics of a study site, whereas the evacuation trigger buffers (ETBs) from WUIVAC are mostly influenced by the wind speed and direction parameters of the FlamMap fire spread model. A moderate fire danger to pedestrians in the most remote wildland locations of the study area is determined. The scenario test results suggest that if a wildfire occurs within 2 km (extreme southwesterly winds) or 6 km (extreme northeasterly wind) of pedestrians in the worst case location within the San Diego border region they would likely not have a sufficient amount of time to reach a nearby safety zone.     

基于大数据的上海市共享汽车出行模式研究

共享汽车是城市交通发展的新潮流,论文基于2018年上海市共享汽车运营大数据和城市POI数据,研究共享汽车用户出行的空间、时间和频次特征,并对用户开展出行模式的K均值聚类分析,以期挖掘典型出行规律,为共享汽车运营优化提供依据。研究表明：① 工作日与休息日共享汽车使用行为差异显著,工作日共享汽车出行较集中于中心城区的混合功能区,早晚通勤高峰使用量大;休息日共享汽车出行空间布局较分散,使用量更高、平均单次使用时长更短且仅存在傍晚一个使用高峰。② 上海市共享汽车出行行为可分为工作日通勤的中高频模式,工作日夜间活动的高频模式,工作日偶尔用车晚餐及返家、偶尔用车远距离通勤和夜间长距离返家的低频模式,休息日日间休闲的高频模式、休息日傍晚离家休闲的中长途低频模式、休息日傍晚在休闲地之间穿梭的远距离低频模式、休息日日间加班的低频模式等10种模式。③ 中高频用户主要使用共享汽车实现远距离通勤和周末中长距离休闲活动,空间区域主要集中在中心城区和副中心区域;低频用户使用共享汽车多为夜间、长距离、休息日加班等公共交通难以满足需求、出租车成本过高的情景,空间分布也比较分散。可通过对用户提供差别化用车方案、优化车辆空间调度等方式推进超大城市共享汽车市场发展。     

不同交通方式下居民城际出行网络结构特征——以“春运”为例

基于多元视角下的居民城际出行网络空间结构测度可以较为全面地刻画出城市间的复杂联系特征。论文利用春运期间腾讯迁徙平台中的人口流动数据,采用复杂网络分析方法以及转变中心性和转变控制力等指标,对比分析了航空、铁路和公路3种交通方式下的中国居民城际出行网络结构特征。结果表明：3种出行方式下,航空联系的线路最少,平均出行距离最长;铁路出行人数最多,其次是公路,航空最少。最大优势流中,北京和上海在国内航空出行联系中起着最重要的控制作用,其次是成都和重庆;铁路出行中,北京和成都占据绝对优势;公路多表现为省级行政中心与周边城市的关联。根据转变中心性和转变控制力划分城市类型,在航空和铁路出行网络中,高中心性—高控制力城市较多;公路出行网络中以高中心性—低控制力城市为主。不同出行方式下的城市聚类得到的网络集群“社区”数量有一定差异,航空、铁路和公路出行依次聚类为7、8和10个“社区”。不同类型出行方式透视的城市网络特征存在较明显的差异：航空出行的城际人口流体现出以全国性枢纽城市为核心分布的核心—边缘结构;铁路表现出以国家铁路大动脉沿线城市为核心,向腹地城市逐渐递减的核心—边缘结构;公路出行的城际人口流则表现为与人口规模匹配的局域强聚集的空间格局。     

南昌城市社会区研究--基于第五次人口普查数据的分析

中国城市社会区分异的研究起步较晚,现有的研究成果基本都是讨论计划经济体制向市场经济体制转轨初期的城市社会区分异现象。本文以南昌市为例,利用分街道第五次人口普查数据,运用因子生态学的方法,对改革开放20年后社会主义市场经济体制作用下的城市社会区进行研究。研究结果显示,住房状况、文化与职业状况、家庭状况和外来人口状况是南昌城市社会区分异的主要影响因子,其中家庭状况因子的空间分布呈现出同心圆模式和扇形模式的复合特征,其他因子的空间分布则具有扇形模式的特征。根据主因子的分布情况,南昌城市社会区可以划分为七类,社会区的空间分布形成一种同心圆和扇形的复合结构。     

基于多交通模式的长春市公园绿地空间可达性研究

城市公园绿地资源空间配置的有效性和公平性对城市规划建设和居民生活具有重要意义.基于百度地图路径规划API及腾讯宜出行大数据,采用集成多种交通模式(步行、公交、驾车)的引力模型与双变量空间自相关分析等方法,综合测度长春市中心城区公园绿地的空间可达性及其供需匹配特征.研究发现:①长春市中心城区的公园绿地空间可达性随出行方式...     

中国城市群人口老龄化时空格局

老龄化和城市化是当今世界面临的两大人口问题。城市群是城市发展到成熟阶段的空间组织形态,是老龄化的特殊区域。本文基于2000年和2010年全国人口普查分县数据,综合应用地理探测器和变异系数等方法,清晰地刻画了中国20个城市群人口老龄化的空间格局及其变化特征,审视了人口老龄化变化的影响因素。结果表明：① 2000年中国城市群人口老龄化平均水平为7.32%,其中12个城市群的人口属于成年型,到2010年时人口老龄化平均水平已上升为9.00%,除珠三角与宁夏沿黄城市群外,其余18个城市群均步入了老年型人口,表现出明显的水平升级与类型替变态势。② 老龄化高值、较高值区域不断向内陆城市群跃迁。③ 城市群老龄化的增量和增速存在显著的区域差异,老龄化水平的低值区和高值区增量少、增速慢,而较低值、中值和较高值区增量多、增速快。总体上表现出区域性城市群——国家级城市群——地区性城市群老龄化速度递减的态势。④ 在城市群内部,老龄化分布格局表现出隆升—塌缩并存的现象。国家级城市群内部老龄化分布格局从隆升结构向塌缩结构转变,城市群中心区人口老龄化水平降低;而地区性城市群和区域性城市群内部老龄化分布格局则从均质结构向隆升结构转变,中心区人口老龄化水平上升。⑤ 城市群人口老龄化是内外因素综合影响的结果,基期老龄化程度、人口年龄结构替变和人口流动性是主导性因素。其中人口年龄结构的普遍性抬升是城市群老龄化升级与类型替变的关键,低龄人口迁入到城市群对人口老龄化则起到“稀释作用”,城市群发育阶段不同引致的聚集和扩散效应对老龄化则起到诱导作用。     

Extracting activity patterns from taxi trajectory data: a two-layer framework using spatio-temporal clustering,Bayesian probability and Monte Carlo simulation

ABSTRACT

Global positioning system (GPS) data generated from taxi trips is a valuable source of information that offers an insight into travel behaviours of urban populations with high spatio-temporal resolution. However, in its raw form, GPS taxi data does not offer information on the purpose (or intended activity) of travel. In this context, to enhance the utility of taxi GPS data sets, we propose a two-layer framework to identify the related activities of each taxi trip automatically and estimate the return trips and successive activities after the trip, by using geographic point-of-interest (POI) data and a combination of spatio-temporal clustering, Bayesian inference and Monte Carlo simulation. Two million taxi trips in New York, the United States of America, and ten million taxi trips in Shenzhen, China, are used as inputs for the two-layer framework. To validate each layer of the framework, we collect 6,003 trip diaries in New York and 712 questionnaire surveys in Shenzhen. The results show that the first layer of the framework performs better than comparable methods published in the literature, while the second layer has high accuracy when inferring return trips.     

Visualizing Diurnal Population Change in Urban Areas for Emergency Management

There is an increasing need for a quick, simple method to represent diurnal population change in metropolitan areas for effective emergency management and risk analysis. Many geographic studies rely on decennial U.S. Census data that assume that urban populations are static in space and time. This has obvious limitations in the context of dynamic geographic problems. The U.S. Department of Transportation publishes population data at the transportation analysis zone level in fifteen-minute increments. This level of spatial and temporal detail allows for improved dynamic population modeling. This article presents a methodology for visualizing and analyzing diurnal population change for metropolitan areas based on this readily available data. Areal interpolation within a geographic information system is used to create twenty-four (one per hour) population surfaces for the larger metropolitan area of Salt Lake County, Utah. The resulting surfaces represent diurnal population change for an average workday and are easily combined to produce an animation that illustrates population dynamics throughout the day. A case study of using the method to visualize population distributions in an emergency management context is provided using two scenarios: a chemical release and a dirty bomb in Salt Lake County. This methodology can be used to address a wide variety of problems in emergency management.     

中国城市用地与人口规模分布时空动态比较——以环渤海地区为例

复合1992-2012年DMSP/OLS稳定夜间灯光等多源遥感数据和统计数据,运用多种城市规模分布理论方法,对城市用地与人口规模分布时空演变特征进行系统比较。结果表明：环渤海地区城市用地规模增长速度明显快于城市人口规模增长速度,城市人口规模分布比城市用地规模分布更为均衡;城市用地规模呈首位型分布但首位优势在减弱,城市人口规模呈位次型分布但首位优势在增强;位序迅速上升的城市主要位于山东省和河北省,位序显著下降的城市主要位于辽宁省。环渤海地区城市规模空间分布呈显著的区域差异和空间极化特征,且城市用地规模分布空间特征比城市人口规模分布更为突出。研究结论可为优化区域城市空间开发格局、促进人地系统可持续发展提供参考。     

城市流动人口长期居留意愿的空间分异及影响因素 ——以长三角城市群为例

以长三角城市群为例,采用多层Logistic回归分析方法,分析城市流动人口长期居留意愿的空间格局及其影响因素.研究发现:1)长三角城市群流动人口长期居留意愿比例为38.09％,其中安徽的城市流动人口以省内流入为主,长期居留意愿比例普遍较高;而沪、苏、浙的城市大多以省际迁移人口为主,高和较高居留意愿城市主要为上海、南京、...     

广州市居民出行特征分析及交通发展的对策

居民出行调查是城市交通规划、建设、管理的基础依据 ,通过对比分析广州市 1998年万户居民出行调查和 1984年居民出行调查的有关数据 ,总结归纳出广州市城市居民出行的规律、变化特征及其原因 ,并针对其特点 ,提出广州市未来交通发展的对策和建议     

Area-level risk factors for heat-related illness in rural and urban locations across North Carolina,USA

An improved understanding of heat vulnerable populations and locations is needed, especially in rural communities. The objective of this study was to identify area-level risk factors for heat-related illness (HRI) at the ZIP code level for urban and rural locations. We aggregated ZIP code-level emergency department visits into rural and urban locations based on population density. Area-level risk factors included previously established heat health risk factors (e.g. poverty, minority) and unexamined area-level risk factors common to rural locations (e.g. mobile homes, agriculture). Due to high spatial autocorrelation, a spatial error regression model was applied to identify risk factors with a significant relationship with HRI. Our results suggest that rural locations are also heat vulnerable, with greater rates of HRI compared to urban locations. Previously unexamined heat-health risk factors, including the number of mobile homes, non-citizens, and the labor-intensity of the agriculture, were all associated with increases of HRI in rural locations. In urban locations, previously established risk factors for heat-related mortality, such as decreased vegetation, living in poverty, and low education attainment were associated with increases in HRI.     

Genetic differentiation of populations of Greenlandic Arctic fox

Most microsatellites are very polymorphic. This makes them powerful markers for observing genetic differentiation between closely related populations. The population structure of the Greenlandic Arctic fox ( Alopex lagopus ) was studied genetically by analysing six polymorphic microsatellite loci of 75 foxes from four populations in different parts of Greenland. Genotypes were determined at the six loci for most of the individuals. Population differentiation was quantified in three different ways both within the total population and pairwise between all populations. The tests were Fisher's exact test, Rho estimates and Fst estimates, all of which supported a highly significant subdivision of the total population, and they showed significant differentiation in allele frequencies between all pairs of localities. It is concluded that the known long-distance migration of the Greenlandic Arctic fox has not resulted in complete genetic mixing of the populations. Fisher's exact test was also used to estimate levels of genetic differentiation between the two colour morphs: white and blue. No difference was found between allele frequencies of the two color morphs in any of the locations, and it was concluded that the white and blue morphs of the Greenlandic Arctic fox share the same habitat, at least during the mating season.     

基于ECOSTRESS地表温度和手机信令数据的城市人口热环境暴露风险评价——以西安市为例

全球气候变暖和城市热岛效应的双重影响使人类社会面临的极端高温风险日益加剧,给城市人口健康和社会经济可持续发展带来严峻挑战,科学评估城市热环境下人口暴露风险已成为当前学术界关注的热点领域。论文基于ECOSTRESS地表温度数据和手机信令数据,以西安市为例,在城市地表温度和人口时空变化分析基础上,构建城市人口暴露风险评价模型,揭示精细化时空尺度上的人口暴露风险时空格局及其动态演变特征。结果表明：(1)西安市夏季一天内的地表温度呈现出明显的波动特征,昼夜地表温度差异较大,白天平均温度为35.5℃,夜间平均温度为21.5℃,白天地表温度空间分布相比夜间具有更明显的空间异质性,且日内所有时刻均存在不同强度的城市热岛效应,热岛分布的变化表现出从聚集状态向离散状态再过渡至聚集状态的特征。(2)西安市人口分布呈单中心结构,73.6%的人口都分布在三环以内,且沿中轴线集中的现象显著,昼夜人口形成了“白天向心、夜间离心”的分布特征。(3)人口暴露的中、高与极高风险区主要呈散点式分布在城市中心区域,且86.6%的极高风险区位于三环以内,而无风险和低风险区主要集中连片分布在城市外围。(4)导致昼夜人口暴露风险...     

基于城市不透水面—人口关联的粤港澳大湾区人口密度时空分异规律与特征

城市人口数据是社会经济各领域的基础数据,高分辨率的空间化城市人口数据则对社会经济各领域的分析和研究具有重要意义。本文首先通过多源遥感技术提取空间分辨率为30 m的粤港澳大湾区2007-2015年间城市不透水面的变化,再利用Dasymetric映射方法得到30 m分辨率的网格化人口密度分布,从而分析大湾区2007-2015年间城市人口的时间和空间变化。通过Google Earth时间序列高分辨率影像采集的样本验证,粤港澳大湾区城市不透水面提取精度均在80%以上;通过统计年鉴中县级人口统计数据,分析大湾区网格化城市人口与统计数据之间的一致性,得到决定系数R²总体在0.7以上。研究表明,粤港澳大湾区城市人口具有特殊的时间和空间分异规律和特征：①大湾区内除了香港和澳门人口分布较稳定,其他城市人口都有不同程度和不同方向的扩张,其中广州、深圳、东莞的人口扩张最为明显;②大湾区城市人口空间分布具有明显的多尺度和多中心特征。总体上,大湾区人口集中在以珠江口为中心的城市群核心区内,离核心区较远的肇庆、江门、惠州人口较为稀疏,城市化程度相对较低,是支撑大湾区经济社会继续深入发展的重要区域。在核心区内,城市人口的分布则在城市尺度和城市群尺度上都体现了多中心分布特征,香港和广州都有多个城市中心,而香港、澳门、深圳、广州则是整个大湾区的4个中心。地理位置上4个中心分布在大湾区的不同地方,可以带动整个粤港澳大湾区的全面发展。研究结果可为粤港澳大湾区在社会经济各领域的分析与规划提供决策支持。