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1.
Voronoi Diagrams and Spatial Analysis of Crime   总被引：1，自引：0，他引：1  
A range of spatial analyses are used in the field of crime mapping, such as kernel density estimation, Ripley's K-function, and spatial autocorrelation, but there is limited use of Voronoi diagrams (VDs). The goal of this article is to contribute to the spatial analysis of crime through the use of VDs. We use four years of commercial robbery data from Campinas, Brazil, and employ several VD techniques: (1) We analyze crime concentrations through the properties of VDs—area and number of vertices—and coverage curve; (2) we introduce a new crime geovisualization with VD in three dimensions; and (3) we apply a network VD technique to crime analysis. The results demonstrate associations between these VD techniques and the ability of the researcher to recognize crime patterns associated with crime concentration, crime along pathways, and the highly regularized distribution of crime in limited areas spatially.  相似文献   

2.
ABSTRACT

Crime often clusters in space and time. Near-repeat patterns improve understanding of crime communicability and their space–time interactions. Near-repeat analysis requires extensive computing resources for the assessment of statistical significance of space–time interactions. A computationally intensive Monte Carlo simulation-based approach is used to evaluate the statistical significance of the space-time patterns underlying near-repeat events. Currently available software for identifying near-repeat patterns is not scalable for large crime datasets. In this paper, we show how parallel spatial programming can help to leverage spatio-temporal simulation-based analysis in large datasets. A parallel near-repeat calculator was developed and a set of experiments were conducted to compare the newly developed software with an existing implementation, assess the performance gain due to parallel computation, test the scalability of the software to handle large crime datasets and assess the utility of the new software for real-world crime data analysis. Our experimental results suggest that, efficiently designed parallel algorithms that leverage high-performance computing along with performance optimization techniques could be used to develop software that are scalable with large datasets and could provide solutions for computationally intensive statistical simulation-based approaches in crime analysis.  相似文献   

3.
This study aims to identify patterns in spatial distribution of Manta birostris along American East Coast by analyzing presence data using a suite of geostatistical techniques. Analysis of data from 1979 to 2008 revealed that the spatial patterns exhibited by the M. birostris include a strong clustering zone off the North Carolina from (however, not all years are represented in that range), Virginia and Maryland coast. Their presence is high near the coastal shelf edge and along the edge of the Gulf Stream. The mix of warm water and high chlorophyll concentration throughout the year in the region seem to create an ideal environment for this clustering pattern. However, in seasons with warmer water temperature, manta rays spread further north and inshore, possibly to avoid competition for prey. The results of geographic weighted regression indicate the role of sea surface temperatures on Manta presence or absence off the main current of the Gulf Stream near North Carolina and Virginia. Knowledge of the spatial distribution of M. birostris can assist in further protecting the species especially from dangers of by-catch and habitat degradation.  相似文献   

4.
《Geomorphology》2001,36(3-4):187-202
Drainage density (Dd), defined as the total length of channels per unit area, is a fundamental property of natural terrain that reflects local climate, relief, geology, and other factors. Accurate measurement of Dd is important for numerous geomorphic and hydrologic applications, yet it is a surprisingly difficult quantity to measure, particularly over large areas. Here, we develop a consistent and efficient method for generating maps of Dd using digital terrain data. The method relies on (i) measuring hillslope flow path distance at every unchanneled site within a basin, and (ii) analyzing this field as a random space function. As a consequence, we measure not only its mean (which is half the inverse of the traditional definition of drainage density) but also its variance, higher moments, and spatial correlation structure. This yields a theoretically sound tool for estimating spatial variability of drainage density. Averaging length-to-channel over an appropriate spatial scale also makes it possible to derive continuous maps of Dd and its spatial variations. We show that the autocorrelation length scale provides a natural and objective choice for spatial averaging. This mapping technique is applied to a region of highly variable Dd in the northern Apennines, Italy. We show that the method is capable of revealing large-scale patterns of variation in Dd that are correlated with lithology and relief. The method provides a new and more general way to quantitatively define and measure Dd, to test geomorphic models, and to incorporate Dd variations into regional-scale hydrologic models.  相似文献   

5.
ABSTRACT

Accurate crime prediction can help allocate police resources for crime reduction and prevention. There are two popular approaches to predict criminal activities: one is based on historical crime, and the other is based on environmental variables correlated with criminal patterns. Previous research on geo-statistical modeling mainly considered one type of data in space-time domain, and few sought to blend multi-source data. In this research, we proposed a spatio-temporal Cokriging algorithm to integrate historical crime data and urban transitional zones for more accurate crime prediction. Time-series historical crime data were used as the primary variable, while urban transitional zones identified from the VIIRS nightlight imagery were used as the secondary co-variable. The algorithm has been applied to predict weekly-based street crime and hotspots in Cincinnati, Ohio. Statistical tests and Predictive Accuracy Index (PAI) and Predictive Efficiency Index (PEI) tests were used to validate predictions in comparison with those of the control group without using the co-variable. The validation results demonstrate that the proposed algorithm with historical crime data and urban transitional zones increased the correlation coefficient by 5.4% for weekdays and by 12.3% for weekends in statistical tests, and gained higher hit rates measured by PAI/PEI in the hotspots test.  相似文献   

6.
While research has repeatedly demonstrated how spatial distributions of crime can be shaped by the presence of facilities such as bars and public transport hubs, the joint influence of different facility types has rarely been explored. Spatial conjunctive analysis of case configurations (also known as qualitative comparative analysis) offers a means to identify the combinations of facility types that are most commonly found around crime events, and has been used in a small number of studies focusing on street robbery. This study extends this limited evidence base by implementing a significance test based on the Monte Carlo method using street robbery data for Austin, Texas. The results show that some of the top-ranking facility type combinations had observed frequencies that were not significantly greater than chance expectations. The accurate identification of the highest-risk environments has important implications for crime prevention.  相似文献   

7.
北京市长安街沿线的扒窃案件高发区分析及防控对策   总被引：2，自引：1，他引：1  
本文利用空间分析方法,对北京市长安街沿线的扒窃类案件的空间分布特征进行了研究。首先分析了长安街沿线的犯罪分布状况,发现该长安街沿线共存在3个异常明显的犯罪高发区域,分别对应于西单商业圈(A)、建国门路段(B)和大望路—四惠路段(C),通过将长安街沿线的常住人口与兴趣点(Point of Interest, POI)分布进行比较,发现案件与POI密度较高的区域存在较高的相关性。随后,利用核密度估计方法和时空热点矩阵方法分析了3个异常明显的案件高发区域内的犯罪活动时空分布模式,结果表明：高发区域A的犯罪高发时段为上午10时至下午18时,其中峰值出现在正午12时,犯罪活动主要集中在区域内的一些大型购物场所内;高发区域B和C的犯罪高发时间均为上午6时和下午18时前后,与早晚交通高峰时间比较一致,犯罪活动主要集中在区域内比较重要的公共交通站点附近。最后,根据长安街沿线案件高发区域内犯罪活动的时空规律性特征,提出了犯罪防控措施与建议。  相似文献   

8.
One challenge facing spatial scientists trying to support public health outreach and intervention in challenging environments is the lack of fine scale spatial data. These data are required to gain a better understanding of both physical and social systems; why disease occurs where it does, and how to disrupt it. While data options exist, including high resolution aerial imagery, remotely sensed data, and even online mapping products like Google Street View, these all come with limitations. One option that has previously been utilized to assess cholera risk is spatial video. Here it is used to map potential mosquito breeding sites in an endemic Dengue and Chikungunya, and emerging Zika impacted community. We show how this method can provide mapping support in the hands of non-specialist public health workers who, working in collaboration with out-of-area geographic information systems (GIS) teams, can identify where to target limited intervention resources. We use a case study of an impoverished informal style Nicaraguan community suffering from a high disease burden to show spatial variation in potential mosquito breeding habitats. A field team collected street-by-street spatial video data to produce fine scale risk maps of standing water and trash locations, which, when interpreted with the associated spatial video imagery, were used to suggest where intervention strategies should be targeted. We also discuss how these same data layers can be used to address other health concerns traditionally found in informal settlements.  相似文献   

9.
Abstract

Ethnic music is a strong indicator of cultural identity. Central and Eastern European ethnic groups have historically been associated with folk music traditions, such as polka, and radio broadcasting patterns in the United States reflect continued demand for and support of this music. Data from the 2000 Census was used to generate maps of the county-level ancestral patterns from European regions traditionally associated with polka music and was compared with the locations of radio stations that play polka. This article demonstrates straightforward quantitative approaches to evaluating these patterns of musical preferences. This study serves as an example for ways in which mapping and GIS can be used as tools for teaching and learning topics related to cultural geography.  相似文献   

10.
Anmeldelser     
Meyer, Marlene: Settlement Patterns and Land-use in Northern Ghana—A Study of the Changes during the period 1963–1991 based on Historical Surveys and recent SPOT-images. Geografisk Tidsskrift 92:101–104. Copenhagen 1992.

A study by Hunter (1966) describes how large areas along the Red Volta River bank, have been abandoned due to river blindness. The mapping of current land-use status and settlements patterns, using multispectral SPOT-satellite images, shows how the border of settlements continue to retreat, whereas new land is being reclaimed for bush fields in the abandoned areas.  相似文献   

11.
《Urban geography》2013,34(4):589-605
This progress report is third in a series that examines the causes of segregation and the meaning and measurement of segregation. In this final report, we begin with the premise that ethnic and racial segregation carries tremendous impacts on the groups involved, altering their daily patterns and their future prospects. Yet the types of consequences that result from segregation depend on group dynamics; the social, political, and economic context; and a variety of contingent circumstances. In this essay, we review the recent literature on the outcomes of urban ethnic segregation and focus on some major themes that emerge from the literature. These themes include health and deprivation effects, how segregation can influence the group's employment prospects, how the fact of concentration may alter degrees of tolerance and intolerance, how segregation can augment levels of crime and violence, and finally the extent to which segregation influences the political and civic life of minority groups.  相似文献   

12.
Large amounts of digital data must be analyzed and integrated to generate mineral potential maps, which can be used for exploration targeting. The quality of the mineral potential maps is dependent on the quality of the data used as inputs, with higher quality inputs producing higher quality outputs. In mineral exploration, particularly in regions with little to no exploration history, datasets are often incomplete at the scale of investigation with data missing due to incomplete mapping or the unavailability of data over certain areas. It is not always clear that datasets are incomplete, and this study examines how mineral potential mapping results may differ in this context. Different methods of mineral potential mapping provide different ways of dealing with analyzing and integrating incomplete data. This study examines the weights of evidence (WofE), evidential belief function and fuzzy logic methods of mineral potential mapping using incomplete data from the Carajás mineral province, Brazil to target for orogenic gold mineralization. Results demonstrate that WofE is the best one able to predict the location of known mineralization within the study area when either complete or unacknowledged incomplete data are used. It is suggested that this is due to the use of Bayes’ rule, which can account for “missing data.” The results indicate the effectiveness of WofE for mineral potential mapping with incomplete data.  相似文献   

13.
DP半岛街头抢劫犯罪案件热点时空模式   总被引：10，自引：4，他引：6  
徐冲  柳林  周素红  叶信岳  姜超 《地理学报》2013,68(12):1714-1723
选取H市中心城区DP半岛作为研究区域,以岛上2006-2011 年发生的街头抢劫案件（共373 起） 作为研究对象,将DP半岛内街头抢劫案件的时空分布特征分别从宏观和局部微观两个尺度层面进行系统的分析。首先,对岛上的街头抢劫案件按年、月和小时进行统计分析,总结其在不同时间尺度上的变化规律：2007 年开始的严打使案件数量逐年减少,直到2010 年才略有回升;春节期间（二月前后） 的案件数量明显高于其他月份;晚上22:00-23:00 期间是案件高发时段。其次,利用Kernel 密度方法对研究区街头抢劫犯罪的宏观空间分布进行整体的辨别,剥离出犯罪热点空间分布,分析热点与道路网和土地利用的关联性,结果表明热点多分布于主干道、通达性高的节点或土地利用混合度高的地方。最后,选出4 个最主要的热点从微观尺度进行分析,PAI 指数表明这4 个热点在时间上是稳定的,从2006 年到2011 年一直存在。依据“热点时空类型矩阵”的时间分布和空间分布模式,将这4 个稳定热点归类到不同微观时空模式,并对每类模式下的街头抢劫犯罪提出有针对性的防控对策,以便优化警力资源的配置、最大限度抑制和减少犯罪的发生。  相似文献   

14.
Despite progress being advanced with spatial approaches to crime and crime control, the geography of crime harm has to date received little attention. The recent development of “Crime Harm Indices”, which weight crimes by an estimate of the relative harm they cause, offers an opportunity to improve on volume based spatial analysis approaches to identify where crime harm concentrates.This study aims to address this issue via the use of a Crime Harm Index (CHI) developed for New Zealand. By contrast to localized ‘harm-spotting’ analysis, we apply a census unit based approach to identify, at a macro level, the neighborhoods and wider communities suffering the highest crime harm in New Zealand. This approach enables harm to be viewed not only as a total Index but as a rate controlled for population and allows for the identification of census based sociodemographic factors which predict harm. Specifically, this paper compares the CHI with the New Zealand Priority Locations Index (PLI), an existing census unit based crime analysis tool which combines crime and demographic variables to identify communities vulnerable to crime and disorder issues.In this study CHI and PLI scores were calculated for Census Area Units (normally containing 3000–5000 population) across New Zealand. Bivariate correlations and a general linear model were used to determine the relationships between the CHI and PLI and additional population related variables. The CHI and PLI were weakly correlated, with population size and urban/rural categorization also accounting for CHI variance. Mapping techniques are used to illustrate outlier locations where the CHI and PLI differ widely and to identify location features which may assist in explaining CHI/PLI differences.This work exemplifies a novel geographic approach to the problem of crime harm with implications for resource allocation at national through to local levels. Wider implications for the theory and practice of crime and crime harm control are discussed, along with limitations of the study and areas for further research.  相似文献   

15.
The spatial distribution of soil types is controlled by a set of environmental factors such as climate, organisms, parent material and topography as well as time and space. A change of these factors will lead to a change in the spatial distribution of soil types. In this study, we use a digital soil mapping approach to improve our knowledge about major soil type distributing factors in the steppe regions of Inner Mongolia (China) which currently undergo tremendous environmental change, e.g. climate and land use change. We use Random Forests in an effort to map Reference Soil Groups according to the World Reference Base for Soil Resources (WRB) in the Xilin River catchment. We benefit from the superior prediction capabilities of RF and additional interpretive results in order to identify the major environmental factors that control spatial patterns of soil types. The nine WRB soil groups that were identified and spatially predicted for the study area are Arenosol, Calcisol, Cambisol, Chernozem, Cryosol, Gleysol, Kastanozem, Phaeozem and Regosol.Model and prediction performances of the RF model are high with an Out-of-Bag error of 51.6% for the model and a misclassification error for the predicted map of 28.9%. The main controlling factors of soil type distribution are land use, a set of topographic variables, geology and climate. However, land use and climate are of major importance and topography and geology are of minor importance. The visualizations of the predictions, the variable importance measures as result of RF and the comparisons of these with the spatial distribution of the environmental factors delivered additional, quantitative information of these controlling factors and revealed that intensively grazed areas are subjected to soil degradation. However, most of the area is still governed by natural soil forming processes which are driven by climate, topography and geology. Most importantly though, our study revealed that a shift towards warmer temperatures and lower precipitation regimes will lead to a change of the spatial distribution of RSGs towards steppe soils that store less carbon, i.e. a decrease of spatial extent of Phaeozems and an increase of spatial extent of Chernozems and Kastanozems.  相似文献   

16.
Whilst analysis of crime for tactical and strategic reasons within the criminal justice arena has now become an established need, predictive analysis of crime remains, and probably always will be, a goal to be desired. Opening a window on this over the last 2 decades, prominent research from academia has focused on the phenomenon of repeat victimisation and more recently ‘near repeat’ victimisation, both firmly grounded in the geography of crime. Somewhat limited to the establishment of near repeat behavioural patterns in whole area data, these can be utilised for crime prevention responses on a local scale. Research reported here however, explores the phenomenon through the examination of serial offending by individual offenders to establish if such spatio-temporal patterns are apparent in the spatial behavioural patterns of the individual burglar, and if so how they may be defined and therefore utilised on a micro rather than macro scale. It is hypothesised that offenders' responsible for more than one series of offences will display consistency across their crime series within time and distance parameters for their closest offences in space. Results improve upon current knowledge concerning near repeat offending being the actions of common offenders. Testing of the extracted data indicates that offenders maintain personal boundaries of ‘closeness’ in time and space even when actions are separated by significant time spans, creating stylised behavioural signatures appertaining to their use of and movement through space when offending.  相似文献   

17.
ABSTRACT

Expanding cities present a sustainability challenge, as the uneven proliferation of hybrid landscape types becomes a major feature of 21st century urbanization. To fully address this challenge, scholars must consider the broad range of land uses that being produced beyond the urban core and how land use patterns in one location may be tied to patterns in other locations. Diverse threads within political ecology provide useful insights into the dynamics that produce uneven urbanization. Specifically, urban political ecology (UPE) details how economic power influences the development decision-making that proliferate urban forms, patterns of uneven access, and modes of decision-making, frequently viewing resource extraction and development through the urban metabolism lens. The political ecology of exurbia, or, perhaps, an exurban political ecology (ExPE), examines the symbolic role nature and the rural have played in conservation and development efforts that produce social, economic, and environmental conflicts. While UPE approaches tend to privilege macroscale dynamics, ExPE emphasizes the role of landowners, managers, and other actors in struggles over the production of exurban space, including through decision-making institutions and within the context of broader political economic forces. Three case studies illustrate the strengths and weaknesses of these approaches, demonstrating the benefits for and giving suggestions on how to integrate their insights into urban sustainability research. Integrated political ecology approaches demonstrate how political-economic processes at a variety of scales produce diverse local sustainability responses.  相似文献   

18.
Population and demographic data at high spatial resolution is a valuable resource for supporting planning and management decisions as well as an important input to socio-economic academic studies. Dasymetric modeling has been a standard technique to disaggregate census-aggregated units into raster-based data of higher spatial resolution. Although utility of dasymetric mapping has been demonstrated on local and regional scales, few high resolution large-scale models exist due to their high computational cost. In particular, no publicly available high resolution dasymetric model of population distribution over the entire United States is presently available. In this paper we introduce a 3″ (∼90 m) resolution dasymetric model of demographics over the entire conterminous United States. The major innovation is to disaggregate already existing 30″ (∼1 km) and 7.5″ (∼250 m) SEDAC (Socioeconomic Data and Applications Center) Census 2000 grids instead of the original census block-level data. National Land Cover Dataset (NLCD) 2001 is used as ancillary information. This allows for rapid development of a U.S.-wide model for distribution of population and sixteen other demographic variables. The new model is demonstrated to markedly improve spatial accuracy of SEDAC model. To underscore importance of high spatial resolution demographic information other than total population count we demonstrate how maps of several population characteristics can be fused into a “product” map that illustrates complex social issues. Specifically, we introduce a “diversity” categorical map that informs (at nominal 3″ resolution) about spatial distribution of racial diversity, dominant race, and population density simultaneously. Diversity map is compared to a similar map based on census tracts. High resolution raster map allows study of race-diversity phenomenon on smaller scale, and, outside of major metropolitan areas, revels existence of patterns that cannot be deduced from a tract-based map. The new high resolution population and diversity maps can be explored online using our GeoWeb application DataEye available at http://sil.uc.edu/. Both datasets can be also downloaded from the same website.  相似文献   

19.
Borrowing methods from epidemiology, studies of spatiotemporal regularities of crime have been booming in various industrialized countries. However, few such attempts are empirical studies using crime data in developing countries due to a lack of data availability. Utilizing a recent burglary dataset in Wuhan, the fourth largest city in China, current research applied the sequential kernel density estimation and the space–time K-function methods to analyze the spatiotemporal changes of hotspots of residential burglaries. The results show that, both spatial and spatiotemporal clustering exists. The hotspots were relatively stable over time. The space–time clustering, however, shows significant concentrations both in space and over time. In addition, analytic results show significant effects of distance decay in terms of occurrences of burglary incidents along the spatial and temporal dimensions. Moreover, findings from the research provide critical information on the space–time rhythm of crime, and therefore can be utilized in crime prevention practice. Finally, the implications of the findings and limitations are discussed.  相似文献   

20.

This study analyzes the extent and pattern of lead contamination along roadways in Trujillo, Venezuela, using traffic counts and soil samples collected in the field. The normalized mean lead level for frontyard samples along major traffic arteries was 200 μgg -1 versus 0 μgg-1 for backyard samples. Furthermore 55%of the frontyard lead levels were hazardous, versus 7% of the backyard samples. This suggests a strong relationship between traffic and soil lead content. However, a relationship between lead level spatial patterns and traffic volume patterns was not established, suggesting that factors beyond traffic volume, such as slope and erosion, play a significant role in contamination patterns.  相似文献   

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