Assessing the social context of wildfire-affected areas. The case of mainland Portugal

Wildfires cause different impacts, depending on the conditions and resilience level of the exposed communities. Wildfire occurrence in mainland Portugal was assessed with regard to socioeconomic and demographic parameters, to identify the most distinctive conditions of fire-affected areas, without implying the existence of causal relationships. The latest population and agriculture census data were used to retrieve conditions at the civil parish level, regarding demographic patterns, social and labor conditions, physical structures and agricultural activities. To identify differences between parishes, two groups were created with the communities that showed the highest and lowest 20% of wildfire incidence between 2007 and 2014, separately for density of fire events and for burned area. A stepwise approach based on classification trees and random Forest methods was applied to identify the best discriminant variables between the groups. First, irrelevant variables were removed by an interactive process based on misclassification rates. The second step used random Forest analysis to the remaining variables to evaluate their importance in distinguishing the groups. In the final step, cluster analysis was applied to test the correspondence between the clusters created with the selected variables and the initial groups. Results showed that parishes with higher fire density have higher population density, higher proportion of young and educated people, larger families and more overcrowded buildings. On the contrary, parishes with larger burned area are less populated, less attractive to foreigners, have a higher proportion of elderly people, more degraded housing conditions and agricultural activities, visible in the density of sheep and goat and pastures, are still relevant. The cluster analysis demonstrated a better performance of the model for wildfire density, revealing a strong association with socioeconomic dynamics with an agreement above 0.85, much higher than for burned areas which is 0.29. Overall, the spatial distribution of wildfire impacts is framed by societal settings and particular conditions must be further understood to improve the coping capacity of affected communities.     

Beyond density: municipal expenditures and the shape and location of development

A clear understanding of the relationship between development patterns and municipal expenditures is complicated by how one chooses to quantify these patterns. Extant literature often employs a single density measure to capture the low-density nature of sprawl. While density provides an intuitive link to economies of scale and congestion costs, it fails to capture other spatial characteristics of sprawl related to centrality, connectedness, and mixed use that may influence municipal expenditures according to Smart Growth and New Urbanism advocates. This study uses Massachusetts orthoimagery data to construct multidimensional measures of residential and commercial land use patterns. Municipal expenditures associated with public works, fire, and police are regressed on multidimensional measures of land use as well as a number of demand controls. Findings indicate that economies and diseconomies do exist with respect to the multidimensional metrics considered. Support is mixed for development patterns emphasized by Smart Growth and New Urbanism advocates.     

“A Newcomer” versus “First Mover”: Retail Location Strategy for Differentiation

In a competitive business environment, retailers brand themselves using unique location strategies. New retailers, especially, use their location strategy to construct a different brand concept from that of the first mover. Therefore, retail chains in the same industry show different location patterns. This article aims to investigate how a new retailer uses its location strategy to differentiate itself from the first mover by comparing the location patterns of two coffee chains. The location patterns of Starbucks Coffee (a “first mover” that employs a premium brand concept) and Ediya Coffee (a “new retail chain” that promotes an economical brand concept) are analyzed for the study. We use a Bayesian spatial model to explore the two retailers' location patterns in Seoul, Korea. Considerable differences are found in the spatial distribution patterns of the two coffee franchises. Starbucks has formed store groupings in prime areas such as the city center based on its cluster location strategy, reflecting its premium brand concept. Conversely, many Ediya Coffee shops have been located in less desirable areas such as fringe areas with low land prices, reflecting their economical brand concept and differentiating the company from Starbucks. These findings lead to a useful marketing implication for a retail startup formulating its location strategy for differentiation. Furthermore, this study's company-level analysis of retail location patterns provides a better understanding of complex retail geography.     

基于多源大数据的深圳市生活性服务业空间格局及影响因素研究

基于生活性服务业POI、手机信令和管理人口数据等大数据,采用最邻近指数、核密度、熵指数及地理探测器方法,探究深圳市生活性服务业的空间格局及影响因素.结果表明:1)深圳市生活性服务业空间分布不均衡,主要集中在中、西部地区,总体呈现"两核-三带"的空间集聚特征;空间上呈带状发展形态,主要集聚在交通主干道及轨道线周边区域.2...     

中国西部冰川度日因子的空间变化特征

在冰川与积雪消融研究中,度日模型应用较为广泛,该模型是基于冰雪消融与气温,尤其是正积温之间的线性关系建立的。度日因子是该模型的重要参数,反映了单位正积温产生的冰雪消融量,其空间变化特征对于不同模型模拟冰雪消融过程的精度有较大影响。 本文根据中国西部不同地区数十条冰川的短期考察和观测资料,分析了西部冰川度日因子的空间变化特征,结果表明：由于青藏高原及其周围地区独特的气候和热量条件,西部冰川度日因子具有明显的区域特征。在同一冰川上,度日因子的空间变化较为明显。从冰川类型来看,与极大陆型及亚大陆型冰川相比,海洋型冰川的度日因子较大。总体看来,西部冰川的度日因子由西北向东南逐渐增大,这与中国西部冰川的气候环境变化趋势是一致的,即在干冷的气候条件下,度日因子较小;而在暖湿的气候条件下度日因子较大。     

区域人口密度函数与增长模式:兼论城市吸引范围划分的GIS方法

区域人口密度函数是研究中心城市对周围区域影响的有效方法。为了控制自然因素对人口密度分布的影响 ,本文的研究地域范围限定在我国四个主要的平原地区 :东北、华北、两湖平原和四川盆地。城市吸引范围是基于重力模型用GIS方法划分的。利用 1982年至 1990年的人口资料进行的模型模拟的结果表明 ,我国区域人口分布特征同西方国家一样 ,呈现出距离衰减特征 ,即随离城市的距离的增加 ,人口密度逐渐下降。由于城市经济增长的原因 ,城市人口增长快于边远地区 ,呈现出向心集聚的趋势。但不同区域集聚程度不一 ,核心城市人口快速增长的区域 ,腹地的人口增长比较迟缓 ;而核心城市人口增长速度一般的区域 ,腹地近乎是同步增长。     

蒙古高原中部气候变化及影响因素比较研究

利用蒙古国中部6个气象站1940~2004年和中国内蒙古自治区中部6个气象站1951~2004年的温度和降水资料,对两地的气候变化及其影响因素作了对比研究。结果表明:20世纪90年代与60年代相比,中国内蒙古6站平均升温1.35℃,蒙古国6站上升1.13℃,2000~2004年与60年代相比:中国内蒙古6站上升1.89℃,蒙古国则为1.37℃,中国内蒙古6站的升温速率高于蒙古国6站。对温度变化趋势作突变性检验,结果表明:温度发生突变时间是纬度较高地区早于纬度较低的地区,大城市早于中小城镇,城市化对温度变化影响比较明显。相对于温度变化,降水变化没有显著性的突变,但有周期变化,中国内蒙古降水变化有2.8年周期,蒙古国有4年、8年的周期,这可能因为中国内蒙古降水水汽主要来源于太平洋,而蒙古国降水的水汽主要来源于北冰洋。     

Seasonal fluctuation of riverine navigation and accessibility in Western Amazonia: An analysis combining a cost-efficient GPS-based observation system and interviews

Accessibility and transportation possibilities are key factors influencing societal conditions and land use patterns in rural areas. Thus, information on the spatial patterns of accessibility and transportation can be of paramount importance in understanding regional differences in development, human livelihood and land use patterns. Analysing spatio-temporal transportation patterns is particularly challenging in areas where everyday transportation is based on unscheduled public transportation and a naturally controlled seasonal transportation network, such as rivers. Here, our aim is to provide information on the seasonal dynamics of riverine transportation and its effects on accessibility patterns in Peruvian Amazonia. We analysed riverine transportation speeds using a low-cost GPS-based riverboat observation system. Spatio-temporal accessibility patterns were generalised from the GPS-observations that were classified according to seasons into the high water season, intermediate season and low water season. We show that navigation along the rivers has a clear seasonal and directional (upstream/downstream) variation, which varies with different types of rivers based on channel morphology. In addition, we conducted interviews with local people to study their perceptions of the seasonal changes in navigation and the accuracy of transportation schedules. As the travel distances in Peruvian Amazonia are generally long, seasonal and directional differences have clear impacts on the overall accessibility patterns in the area and on the livelihoods of riverine inhabitants. Furthermore, the lack of clearly scheduled transportation causes considerable uncertainty about transportation options for local communities. The baseline information of the seasonal and directional variation of riverine transportation and travel speeds provided by our work is usable in further accessibility and livelihood analyses for Peruvian Amazonia, but it may also be useful in other areas relying on riverine transportation.     

Socio-demographic area of Delhi

"This paper evaluates statistically and displays cartographically previously untabulated and unpublished data from the 1971 Census of India for the entire population of Delhi. Data pertain to Delhi's census 'charges' (wards) and were originally tabulated in the form of 348 variables relating to occupational distribution, migration, and non-worker status--each classified separately by gender. Although these data are subject to multiple reporting errors and fallacious ecological inferences, they constitute the largest database yet assembled for comparative analysis of Indian intra-metropolitan patterns and structures. Socio-demographic patterns and areas are identified reflecting the traditional-modern, formal-informal, familistic, and ethnic constituents of the national capital of India."     

北京城市蔓延的测度与分析

针对现阶段我国城市用地快速扩张和无序蔓延的现实问题, 以北京市在1996~2004 年期间的城市扩展作为研究案例, 提出可以从城市扩展形态、扩展效率和外部影响等三个方面来判识城市蔓延现象, 并提出基于地理空间指标体系的城市蔓延测度方法, 主要由涉及人口、经济、土地利用、农业、环境和城市生活等方面的13 项指标所组成。实证分析结果表明, 该方法可以有效地测度和量化研究区城市蔓延的特征: ① 建设用地斑块具有明显的破碎化和不规则化趋势, 缺乏良好的规划控制, 不连续开发、条带式开发和跳跃式开发特征明显, 扩展形态不尽合理; ② 新增建设用地的建设密度和容积率较低, 并且新增用地的人口密度和经济产出水平均低于原有用地绩效, 扩展效率不高; ③ 城市蔓延占用大量的耕地和开敞空间、加重了交通负担, 对农业、环境和城市生活存在显著的负面影响。     

COMPREHENDING COMPLEXITY

Since 1905 the Bureau of the Census has devised and applied concepts and criteria for delineating metropolitan areas and has published statistics describing them. The Office of Management and Budget (OMB) and its predecessor, the Bureau of the Budget, have defined metropolitan areas for use by federal agencies since introducing standard metropolitan areas (SMAs) for the 1950 census. In the late 20th century, new national United States settlement forms emerged, and distinctions between urban and rural areas or between metropolitan and nonmetropolitan areas lost both their theoretical and practical significance. A proposed system of national settlement areas, applied experimentally to eight diverse states, uses counties (towns and cities in New England) as basic statistical units, with each categorized by its population density as ranked within both its state and the nation. Relative population density alone is an adequate and appropriate surrogate for activity patterns and interaction among geographic units, approximating the patterns delineated by current practice, while blanketing the nation with non-overlapping statistical aggregates. [Key words: metropolitan area definition, urban population density, census geography.]     

建成环境对城市居民日常出行碳排放的影响——以开封市248个居住区为例

居住区是居民日常生活最基本的空间单元,其建成环境对出行碳排放的影响是学术界关注的焦点。基于大样本调查数据核算居民各类出行碳排放,通过POI抓取、空间句法、网络分析等方法识别开封市主城区成规模的248个居住区的建成环境特征,借助核密度和GWR等方法剖析居住区尺度居民各类出行碳排放的空间分异规律。结果表明：① 城市内部居民出行碳排放空间差异显著,居住区公共服务供给的公平性问题突出,外圈层快速扩张区域应作为城市碳减排工作的关键区域;② 居住区尺度能较好地揭示建成环境对出行碳排放的影响,路网设计、建筑密度、土地利用混合度等因素对各类出行碳排放的作用机理差异较大,作用强度亦存在不同方向上的空间渐进规律;③ 根据出行碳排放结构及其对应的建成环境指标可识别出外层高密度欠通达低混合型居住区碳排放水平较高,内层低密度高通达高混合型居住区碳排放水平较低。研究结果可为居住区空间重构和城市碳排放的分区规划与治理提供科学依据。     

Understanding the spatial distribution of crime in hot crime areas

Hot crime areas are always targeted for police patrol to deter crimes. While much research has studied the distribution patterns of hot crime areas, research on the spatial distribution of crime within hot crime areas remains limited. Using burglary records in a large Chinese city, the ‘hottest’ place with the highest crime density was located using two spatial temporal kernel density estimation methods. The results indicated that the majority of crime within hot crime areas was concentrated within a small area distant from the hot area's center. These results provide a micro view of crime distribution within hot crime areas. Our analysis indicates that the results will not be affected by the methods adopted in identification of hot areas. This research is expected to improve the efficiency of police patrols.     

Spatio-temporal characteristics of intra-urban land cover in the cities of China and USA from 1978 to 2010

Urban land cover has major impacts on a city''s ecosystem services and the inherent quality of its urban residential environment. The spatio-temporal distribution of impervious surface area and green areas in Chinese cities has exhibited a significantly marked difference in comparison with USA cities. This study focused on monitoring and comparing the spatio-temporal dynamics, land cover patterns and characteristics of functional regions in six Chinese (n=3) and USA (n=3) cities. The study data were collated from Landsat TM/MSS imagery during the period 1978-2010. Results indicate that Chinese cities have developed compactly over the past three decades, while development has been notably dispersed among USA cities. Mean vegetation coverage in USA cities is approximately 2.2 times that found amongst Chinese urban agglomerations. Land use types within Chinese cities are significantly more complex, with a higher density of impervious surface area. Conversely, the central business district (CBD) and residential areas within USA cities were comprised of a lower proportion of impervious surface area and a higher proportion of green land. Results may be used to contribute to future urban planning and administration efforts in both China and the USA.     

THE IMPACT OF CHANGES IN PRICING POLICY UPON TRANSIT RIDERS OF VARYING AGES IN CHICAGO *

The elderly and young represent a significant segment of the transit-dependent ridership in metropolitan areas. The impacts of a change in pricing structure and transfer policy upon these groups are examined using survey data generated from riders of the Regional Transportation Authority in Chicago before and after a major restructing of fares and transfer policy. Results indicate that the elderly and young differ from the general population of respondents in their sensitivity to these changes. Moreover, it appears that the restructuring of fares did not adversely affect ridership patterns for these subgroups of transit users.     

2000–2015年京津走廊耕地和建设用地变化监测研究（英文）

Rapid peri-urbanization has become a new challenge for sustainable urban-rural development worldwide. To clarify how unprecedented urban sprawl at the metropolitan fringe impacts urban-rural landscape, this study took the Beijing-Tianjin corridor of Beijing-Tianjin-Hebei metropolitan area, one of the largest urban clusters in China, as a typical example. By using Landsat-based landscape metrics and a practical methodology, we investigated the landscape changes and discussed the potential reasons in the context of rapid peri-urbanization of China. Specifically, multi-temporal land use maps derived from Landsat images were used to calculate landscape metrics and analyze their characteristics along the urban-rural gradients. The practical methodology was used to monitor spatio-temporal characteristics of landscape change in large metropolitan areas. The results showed that landscape patterns in the area had changed greatly from 2000 to 2015 with characteristics of construction land sprawl and arable land shrinkage. The intensity and scale of landscape changes varied along the urban-rural gradients. Sampled plots in urbanized areas and rural areas demonstrated distinguishable landscape patterns and significant differences. Urban areas had more heterogeneous and fragmented landscapes than rural areas. Peri-urban areas in general experienced higher levels of land diversification than rural areas. Rural residential land appeared to be more aggregated near Beijing and Tianjin cities. Besides, our findings also indicated that urban expansion was largely responsible for landscape patterns.The findings of this study potentially provide strategical insights into landscape planning around mega cities and sustainable coordinated urban-rural development.     

Can gains in efficiency offset the resource demands and CO2 emissions from constructing and operating the built environment?

Urbanization is a demographic, economic, and land transformation process. Building construction and operation are integral aspects of urban land use change and contribute to material and energy resources consumption and the resulting carbon dioxide (CO₂) emissions in urban areas. In this paper, we ask two questions regarding the urbanization process: 1) Do the land, material, and energy use efficiencies associated with the construction and operation of buildings increase over time? 2) Do the gains in resource use efficiencies offset the increases in resource demands due to the magnitude of urbanization? To answer these questions, we use a systematic approach similar to a material flow analysis and apply it to the Pearl River Delta, a rapidly urbanizing region in China. We use a combination of satellite data and official statistics to evaluate changes in urban population density and building density from 1988 to 2008. Both density measures decrease from 1988 to 2003; after 2003, building density increases while population density continues to decline. We also track the indirect impacts of urban land expansion on material and energy demands and associated CO₂ emissions using concrete and heating/cooling as proxies for building construction and operation, respectively. Throughout the study period, structural changes and efficiency gains decrease the demand per unit floor area for both building materials and energy. However, the efficiency gains are outstripped by the magnitude of urban expansion, therefore leading to an increase in the demand for resources and CO₂ emissions per capita. Our results show that focusing only on gains in efficiency for individual buildings without considering the scale of urban expansion results in underestimate of the cumulative energy, material, and greenhouse gas emissions impacts of urbanization. We emphasize the distinction between the rates versus the accumulations of these impacts over spatial and temporal scales. We discuss the relevance of the Environmental Kuznets approaches to tackling environmental impacts that are cumulative in nature and may lead to irreversible changes in the environment. We conclude that tracking the energy, materials, and emissions impacts of urbanization requires a multi-scale approach that ranges from the individual building to the urban region.     

基于元胞自动机的城市发展密度模拟

元胞自动机CA越来越多地被用于模拟复杂的城市系统,但这些模拟基本不考虑城市的发展密度。不同的城市发展密度会对城市的形态有很大的影响,有必要将城市的发展密度引进CA的城市模拟中,以获得更好的模拟结果。本文将密度梯度函数引进了CA模型的转换规则中,并定义‘灰度’来反映状态的转换。利用该模型对不同可能的城市发展组合进行了模拟,为城市规划提供了辅助依据。     

Assessing the Impact of Airborne Toxic Releases on Populations with Special Needs

In this article, we 1) develop and demonstrate an approach for assessing the population at risk to airborne releases of extremely hazardous substances, 2) examine the relationship between potential sources of chemical hazards and the special needs population in a medium‐sized metropolitan area (Cedar Rapids, Iowa), and 3) determine whether the distribution of environmental risks disproportionately impacts the special needs population. Our approach provides a comprehensive view of the risk burden imposed on the population by examining the effects of multiple sources of toxic releases. Disproportionate impacts are evaluated by comparing the existing distribution of the special needs population at risk to 1,000 randomly simulated distribution patterns. The results indicate that a significantly high proportion of the special needs population resides in areas susceptible to worst‐case toxic releases.     

Spatial concentration patterns of South Asian low-skilled immigrants in Oman: A spatial analysis of residential geographies

Oman is a major recipient of South Asian labor immigrants, and correspondingly, the demographic statistics reveal that the non-Omani populations primarily are constituted of the Asians. This research examines whether the largest immigrant groups (Indian, Bangladesh, Pakistani and Sri Lankan) in Oman form residential clusters according to their work skills (higher and lower skills). The residential geographies of South Asian workers at the subnational administrative boundaries have been investigated in the current study. Empirically, the study employs the use of Location Quotients (LQ) and Entropy Index within the GIS environment to spatially analyze the immigrant residential distributions based on their work skills. Interestingly, the findings of this research confirm the primary influence of geography on the residential patterns of the low-skilled immigrants. Initially, Al-Batnah governorates constituted the main destinations of low-skilled Bangladeshis. Further, the research also highlights significant clusters of Indian and Pakistani high-skilled immigrants in urban residential communities within the Muscat governorate. In addition, the South Asian are found to be a relatively constant stream of immigrants to inhabit the Omani urban areas, with employments in various public and private economic sectors (e.g. educational, health, manufacturing, finance, business etc.). This concentration pattern of low skilled immigrants is attributable to the need to labor shortages of native populations in certain jobs. The research results also indicate that the rural and suburban communities of Al-Batnah coastal plain not only have a greater number of low skilled immigrants but also display equitable distributions of the four South Asian groups in the residential settlements. For policy makers, it is imperative to understand the spatial patterns of low and high-skilled immigrants in Oman, which exert several geographic, economic, social and demographic implications. The significant role of immigration in development necessitates the identification of the predominant destinations for immigrants. It has been observed that the immigrants are crucial to several sectors of Omani urban economy, and urban areas with a large number of immigrants are more likely to grow and expand faster. In addition, the immigrants’ laborers offer potential economic benefits to the host country, which include fostering entrepreneurial activities, small businesses and reducing wages, especially in unskilled jobs. Despite the negative impacts of immigration (e.g. losing national cultural and creating socio-spatial segregation), the diverse and distinctive locational patterns of immigrant groups in Oman contribute crucially to the socioeconomic development and immigration policy. Yet understanding of the spatial dynamics of immigration in structuring the Omani regions and its influences remains very limited. Thus, further research accounting for the different spatial and attribute ancillary data is necessitated.