首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 328 毫秒
1.
ABSTRACT A common problem with spatial economic concentration measures based on areal data (e.g., Gini, Herfindhal, entropy, and Ellison‐Glaeser indices) is accounting for the position of regions in space. While they purport to measure spatial clustering, these statistics are confined to calculations within individual areal units. They are insensitive to the proximity of regions or to neighboring effects. Clearly, since spillovers do not recognize areal units, economic clusters may cross regional boundaries. Yet with current measures, any industrial agglomeration that traverses boundaries will be chopped into two or more pieces. Activity in adjacent spatial units is treated in exactly the same way as activity in far‐flung, nonadjacent areas. This paper shows how popular measures of spatial concentration relying on areal data can be modified to account for neighboring effects. With a U.S. application, we also demonstrate that the new instruments we propose are easy to implement and can be valuable in regional analysis.  相似文献   

2.
3.
The issue of reallocating population figures from a set of geographical units onto another set of units has received a great deal of attention in the literature. Every other day, a new algorithm is proposed, claiming that it outperforms competitor procedures. Unfortunately, when the new (usually more complex) methods are applied to a new data set, the improvements attained are sometimes just marginal. The relationship cost‐effectiveness of the solutions is case‐dependent. The majority of studies have focused on large areas with heterogeneous population density distributions. The general conclusion is that as a rule more sophisticated methods are worth the effort. It could be argued, however, that when we work with a variable that varies gradually in relatively homogeneous small units, simple areal weighting methods could be sufficient and that ancillary variables would produce marginal improvements. For the case of reallocating census data, our study shows that, even under the above conditions, the most sophisticated approaches clearly yield the better results. After testing fourteen methods in Barcelona (Spain), the best results are attained using as ancillary variable the total dwelling area in each residential building. Our study shows the 3‐D methods as generating the better outcomes followed by multiclass 2‐D procedures, binary 2‐D approaches and areal weighting and 1‐D algorithms. The point‐based interpolation procedures are by far the ones producing the worst estimates.  相似文献   

4.
SPATIAL DEPENDENCY OF SEGREGATION INDICES   总被引:3,自引:0,他引:3  
A few researchers have mentioned the scale sensitivity of segregation index, D. In this paper, I discuss analytically and empirically why using large enumeration areal units usually results in low segregation measures, and using small areal units produces relatively high segregation measures. The discussion is also applicable to the multi-group variant of D. A major finding is that if people of the same ethnic groups are positively spatially auto-correlated, increasing the size of areal units of analysis may not lower D initially, because only people of the same group are added. But enlarging the areal units subsequently may include population of other ethnic groups, and therefore could lower D. However, if the boundaries of the larger enumeration units are drawn to include only population of the same group, then D will not change significantly. Both the spatial autocorrelation of ethnic group population and zonal pattern are critical factors in determining the scale sensitivity of D.  相似文献   

5.
张汉 《人文地理》2012,27(2):6-11
通过对宁波天一广场治理机制的个案研究发现,中国新城市空间的治理已经成为中国共产党进行党建工作的一项地域性工程。在市场化改革与地方间竞争的背景下,地方党政机关极为关注基于行政辖区的地域性身份认同和利益,有意识的与非公有部门的经济精英共同塑造和强化地域性身份认同和利益诉求,并结成新形式的城市治理联盟。中共及其附属的群众组织的地方组织力量,通过地域导向的组织重构,加强了对非公有部门的控制力,填补了市场转型造成的新城市空间治理的真空,也加强了自身在新城市空间中的组织网络和治理能力。  相似文献   

6.
The exploitation of natural populations of red deer forms an important land use in large areas of the Scottish Highlands, especially the highest and most rugged parts of the region. Despite its areal significance red deer land use has been the subject of very little geographical investigation.

The ecology of red deer is an important factor in the Highland land use situation, and environmental controls on the characteristics of the red deer resource are strong. Wide spatial variations exist both in deer population densities and in stag weights. Considerable difficulties arise in regard to the availability of comprehensive population and weight data, but despite these difficulties certain areas, particularly in the borderlands between Inverness‐shire and Ross‐shire, stand out as the most productive deer areas.  相似文献   

7.
ABSTRACT On a sample of U.S. urbanized areas in 2000, we test theoretical hypotheses of the effect of land‐use controls on the spatial size of urban areas. We find that minimum lot‐size zoning and maximum FAR restrictions expand the urban area, while maximum lot‐size zoning, urban growth boundaries, minimum square footage limits, maximum building permit restrictions, minimum person per room controls, and impact fees contract the urban area. All of these findings are consistent with theoretical predictions although the effect of urban growth boundaries and minimum square footage limits are not statistically significant.  相似文献   

8.
Alestalo J 《Fennia》1983,161(2):263-288
Trends in the spatial distribution of the population of Finland from 1880 to 1980 are examined using official data from population registers and censuses. "Cumulative maps and graphs and concentration indices were applied as methodological tools, and the administrative communes were taken as the areal units for a chorological matrix." The results show an increasing concentration of the population beginning in the latter half of the nineteenth century, although urbanization levels remain low in comparison with most industrialized European countries. Differences in population distribution by occupation are also considered.  相似文献   

9.
陈双  周锐  高峻 《人文地理》2020,35(4):130-138
开展城市群人口流动研究对促进区域人口有序流动和城市群协同发展具有重要的理论和实践指导意义。本文基于腾讯迁徙大数据,运用GIS空间统计和K-shell分解等方法,从人口流动总量、位序、时序和网络层级等方面,对我国长三角城市群2018年春运期间的人口流动特征进行系统研究。结果表明:①长三角城市群春运期间大规模的“返乡流”和“返城流”呈现明显的对称性,并分别于除夕和第一个工作日达到最高峰。②经济发展水平相对较高的上海、苏州、杭州等为劳动力输入型城市,而经济发展水平相对较低的盐城、安庆和滁州等为劳动力输出型城市。③长三角城市群内部人口流动网络具有明显的层级特征,其中上海和杭州是人口辐射核心城市,上海-合肥、上海-南京、上海-杭州等是人口流动的主体路径;空间上东部-西部横向人口流动最为频繁,大体呈现“Z”字形。  相似文献   

10.
以全国321个地级以上行政区为研究对象,基于城市间汽车、火车和航空班次联系测算各城市对外联系强度,通过核密度估计、位序-规模及探索性空间数据分析,对多元交通流视角下城市间交通流强度的空间格局进行提取和解析。研究表明:在整个城市体系中,高位次城市规模凸显,中小规模城市有待于进一步发育。基于公路和铁路联系的城际交通流分别表现为由沿海向内陆逐级减弱、以国家铁路大动脉沿线为中心的核心-边缘结构;基于航空联系的城际交通流表现出高度极化和点状镶嵌特征。  相似文献   

11.
This paper introduces an approach to the measurement of locational phenomena in a spatial hierarchy using entropy statistics. A number of such statistics suitable for the study of spatial aggregation are derived, and each of these statistics is decomposed at different levels of the spatial hierarchy using principles of decomposition first applied by Theil. These decomposition statistics are compared with the variance analysis applied by Moellering and Tobler and with the spatial entropy measure suggested by Curry. The use of these statistics is then illustrated by data from the Reading subregion and New York City, and the paper is concluded with an analysis of a possible role for entropy and information in problems involving equal-area zoning.  相似文献   

12.
Areal interpolation involves the transfer of data from one zonation of a region to another, where the two zonations of space are geographically incompatible. By its very nature this process is fraught with errors. However, only recently have there been specific attempts to quantify these errors. Fisher and Langford (1995) employed Monte Carlo simulation methods, based on modifiable areal units, to compare the errors resulting from selected areal interpolation techniques. This paper builds on their work by parameterizing and visualizing the errors resulting from the areal weighting and dasymetric methods of areal interpolation. It provides the basis for further research by developing the methodology to produce predictive models of the errors in areal interpolation. Random aggregation techniques are employed to generate multiple sets of source zones and interpolation takes place from these units onto a fixed set of randomly generated target zones. Analysis takes place at the polygon, or target zone level, which enables detailed analysis of the error distributions, basic visualization of the spatial nature of the errors and predictive modeling of the errors based on parameters of the target zones. Correlation and regression analysis revealed that errors from the areal weighting technique were related to the geometric parameters of the target zones. The dasymetric errors, however, demonstrated more association with the population or attribute characteristics of the zones. The perimeter, total population, and population density of the target zones were shown to be the strongest predictive parameters.  相似文献   

13.
以关天经济区为案例地,运用空间统计工具,将市、县、镇三个尺度的人口空间变化纳入统一的分析框架,探究不同尺度的人口时空格局及影响机制,分析尺度间差异。研究表明:①在人口空间格局上,市级层面西安市是经济区人口分布的核心;县级层面区域人口沿渭河呈带状分布格局;镇级层面人口以西安为中心沿交通轴线向外围递减;②经济区人口格局整体呈现空间集聚趋势,并在各尺度间表现出明显差异。在市级层面,区域人口加速向西安集中;在县级层面,人口主要向地级市市区集中;在镇级层面,出现两种人口集聚路径:一是地级市市区内,人口大量向近郊集聚,中心城区人口快速缩减,郊区化特征明显,二是在市区外围,人口明显向各县城集聚,绝大多数乡镇人口下降。  相似文献   

14.
This paper examines indigeneity and spatial production in the city of Winnipeg, home to the largest urban Indigenous population in Canada. Using data from semi‐structured interviews with Indigenous inhabitants, municipal officials, and Indigenous leaders, this paper argues that the right to the city and to difference are deradicalized for urban Indigenous communities. Indigenous engagement in processes of everyday urbanism occurs through broadly participatory public consultation and through mechanisms designed by City Hall to communicate with Indigenous communities about municipal initiatives. To arrive at a more robust and meaningful Indigenous urban visibility in Canadian cities, spatial production and programming mechanisms will need to be reconstituted. Guided by the perspectives of Indigenous participants, this paper considers some of what Indigenous urbanism might yet entail. Fulfilling coexistence and reconciliation is dependent on enabling Indigenous urbanism to guide the course taken in urban governance, spatial planning, and the built environment of Canadian cities.  相似文献   

15.
Effective catchment monitoring requires an integrative approach for selecting remotely sensed data to monitor land‐cover change. Catchment analyses and monitoring requirements in the Maroochy and Mooloolah River Catchments (south‐east Queensland) were addressed by linking government and community information needs to appropriate scales of remotely sensed data and processing routines. A hybrid image classification approach applied to Landsat Thematic Mapper image data acquired in 1988 and 1997 provided catchment scale land‐cover maps (with accuracies of 73% and 84%). Land‐cover change maps derived from post‐classification comparison provided information on the spatial distribution and type of land‐cover changes between 1988–1997. Land‐cover change was dominated by activities related to urban residential expansion (suburban and rural residential) and agricultural expansion (sugar cane farms). Significant spatial variations in the geometric registration accuracy of the image data sets and classification accuracies produced moderate to low change detection accuracies. However, the framework and community consultation used for selecting and processing data ensured the resource managers and community groups were fully aware of the limitations of the land‐cover change mapping process and that the output images were suitable for incorporating in resource monitoring activities.  相似文献   

16.
It is well established that using data summaries for a set of geographic areas or zones to estimate the parameters of a statistical model, commonly called ecological inference, frequently leads to the modifiable area unit problem (MAUP). In this article, the zoning effect of the MAUP is investigated for a range of scales. A zoning distribution is defined, and then used to characterize the zoning effect for parameter estimates from ecological analyses. Zone‐independent parameter estimates are obtained using the mean of the zoning distribution, and assessed using the variance of the zoning distribution. Zoning distributions are illustrated for parameter estimates from two ecological regression models at multiple scales using Australian National Health Survey data. For both a continuous response variable and a binary response variable, the empirical zoning distributions are unimodal, relatively symmetrical with appreciable variation, even when based on a large number of zones. The “ecological mean,” or expected value of the empirical zoning distribution at each scale, displays systematic variation with scale and the zoning distribution variance also depends on scale. The results demonstrate that the zoning effect should not be ignored, and the sensitivity of ecological analysis results to the analysis zones should be assessed.  相似文献   

17.
The aim of this paper is to analyze the intraurban spatial distributions of population and employment in the agglomeration of Dijon (regional capital of Burgundy, France). We study whether this agglomeration has followed the general tendency of job decentralization observed in most urban areas or whether it is still characterized by a monocentric pattern. To that purpose, we use a sample of 136 observations at the communal and at the IRIS (infraurban statistical area) levels with 1999 census data and the employment database SIRENE (INSEE). First, we study the spatial pattern of total employment and employment density using exploratory spatial data analysis. Apart from the CBD, few IRIS are found to be statistically significant, a result contrasting with those found using standard methods of subcenter identification with employment cut‐offs. Next, in order to examine the spatial distribution of residential population density, we estimate and compare different specifications: exponential negative, spline‐exponential, and multicentric density functions. Moreover, spatial autocorrelation, spatial heterogeneity, and outliers are controlled for by using the appropriate maximum likelihood, generalized method of moments, and Bayesian spatial econometric techniques. Our results highlight again the monocentric character of the agglomeration of Dijon.  相似文献   

18.
We compare Tobler's pycnophylactic interpolation method with the geostatistical approach of area-to-point kriging for distributing population data collected by areal unit in 18 census tracts in Ann Arbor for 1970 to reconstruct a population density surface. In both methods, (1) the areal data are reproduced when the predicted population density is upscaled; (2) physical boundary conditions are accounted for, if they exist; and (3) inequality constraints, such as the requirement of non-negative point predictions, are satisfied. The results show that when a certain variogram model, that is, the de Wijsian model corresponding to the free-space Green's function of Laplace's equation, is used in the geostatistical approach under the same boundary condition and constraints with Tobler's approach, the predicted population density surfaces are almost identical (up to numerical errors and discretization discrepancies). The implications of these findings are twofold: (1) multiple attribute surfaces can be constructed from areal data using the geostatistical approach, depending on the particular point variogram model adopted—that variogram model need not be the one associated with Tobler's solution and (2) it is the analyst's responsibility to justify whether the smoothness criterion employed in Tobler's approach is relevant to the particular application at hand. A notable advantage of the geostatistical approach over Tobler's is that it allows reporting the uncertainty or reliability of the interpolated values, with critical implications for uncertainty propagation in spatial analysis operations.  相似文献   

19.
In an earlier study of Scottish fertility (Jones, 1975) it was concluded that a substantial part of the areal variability in county and major city Crude Birth Rates could be attributed to variations in age structure and, to a lesser extent, socio‐economic composition. Because Crude Birth Rate levels are affected by population composition this study seeks to determine the extent to which areal variations in reproduction can be attributed to behavioural rather than structural effects. It is suggested that areal differences in Scottish reproductive behaviour reflect well defined, deeply ingrained and temporally persistent differences within Scottish society.  相似文献   

20.
Regional design, long a backbone for spatial planning, even if under other names, has become topical again for two reasons – as a key strategy and as a key tool in spatial management. This is due to several reasons. New conditions of urbanization that result from the convergence of several factors highlight the need for spatial strategy formation and application at supra-metropolitan scales. These new conditions include globalization, climate change, booming urban population, increased mobility and interconnectivity, and new infrastructure technologies. These forces driving urbanization today and into the future play out at the urban scale, which is increasingly encompassed in the city-region. The solutions to the impacts and problems that these forces cause must be dealt with by a strategic urbanism at a scale that matches. This scale of urbanism can be denoted as regional design. To justify these claims and to understand the origins of regional design and its relevance today and into the future, the master strokes in its history are presented next. After that, we discuss current concepts and practices in regional design. In conclusion, we offer answers to the question: why a resurgence of regional design?  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号