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Victor’s hat     
Elvin Wyly 《Urban geography》2017,38(3):323-326
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The combination of crime mapping and geospatial analysis methods has enabled law enforcement agencies to develop more proactive methods of targeting crime-prone neighborhoods based on spatial patterns, such as hot spots and spatial proximity to specific points of interest. In this article, we investigate the spatial and temporal patterns of the neighborhood crimes of aggravated assault and larceny in 297 census tracts in Miami–Dade County from 2007 to 2015. We use emerging hot spot analysis (EHSA) to identify the spatial patterns of emerging, persistent, continuous, and sporadic hot spots. In addition, we use geographically weighted regression to analyze the spatial clustering effects of sociodemographic variables, poverty rate, median age, and ethnic diversity. The hot spots for larceny are much more diffused than those for aggravated assaults, which exhibit clustering in the north over Liberty City and Miami Gardens and in the south near Homestead, and the ethnic heterogeneity index has a moderate and positive effect on the incidence of both larceny and aggravated assaults. The findings suggest that law enforcement can better target prevention programs for violent versus property crime using geospatial analyses. Additionally, the ethnic concentration of neighborhoods influences crime differently in neighborhoods of different socioeconomic status, and future studies should account for spatial patterns when estimating conventional regression models.  相似文献   

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The Journal of Geography publishes work on geography education from throughout the world. This article investigates the origins of articles from 2008–2015, uncovers differences in rejection rates among articles from developed versus less developed regions, and makes suggestions to improve publication success by non-North American authors.  相似文献   

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Forestland divestment by vertically integrated forest products companies (VIFPCs) has spurred significant forest ownership change. To illuminate these dynamics, we examined land sales after VIFPC divestment, subsequent acquisitions of conserved land, and trends in recreational access in Wisconsin. We documented changes from 1999 to 2015 with analysis of tax program records and profiles of the state’s largest investor owners, Plum Creek and The Forestland Group. Nearly all VIFPC land was sold to investors, public agencies, or smaller corporate and private owners. State tax and land acquisition programs buffered these changes: 70% of large private ownership land was retained in the forest tax program and another 16% was acquired by public and nonprofit owners. More than one-quarter of divested forestland was placed in conservation easements. Nonetheless, large private forestland open to public recreation declined by almost one-third. Investor strategies and conservation programs shaped the provision of forest benefits during ownership transitions.  相似文献   

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Li  Yuanyuan  Tan  Minghong  Hao  Haiguang 《地理学报(英文版)》2019,29(3):323-333
Journal of Geographical Sciences - From 1992 to 2015, ecological environment has been threatened by the changes of cropland around the world. In order to evaluate the impact of cropland changes on...  相似文献   

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Knowledge-intensive economic resurgence and social restratification are evidently reshaping the intra-urban space of Los Angeles .In particular, the expansion of white-collar employment is inducing marked readjustments in the geography of housing for these workers, and is promoting significant gentrification of inner-city neighborhoods. Existing accounts of gentrification in the United States are briefly adjudged in relation to (a) the recent historical record of urban change and (b) the theory of land redevelopment. A cartographic and statistical analysis of white-collar residential change in Los Angeles County is then undertaken. The analysis points to the evolving spatial structure of pertinent job opportunities together with related land redevelopment dynamics as the dominant factors underlying recent shifts in white-collar residential activity in the County. Further investigation suggests that gentrification trends in Los Angeles represent a special and problematical case of this broad process of white-collar residential change. .  相似文献   

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人口和人均食物需求的增加对全球耕地产生了显著的影响。利用欧空局提供的精度为300m的最新土地覆被产品,文章分析了1992-2015年全球耕地的时空变化趋势和耕地转化特征。结果显示:1)在1992-2004年间全球耕地面积增长迅速,而在2004-2012年间耕地增长缓慢,2012年后耕地有缓慢减少的趋势。2)在洲尺度上,非洲耕地有一直增长的态势,而其他洲耕地都经历了耕地转型,有先增长后下降的趋势;在收入较高的国家,耕地多有下降的趋势。3)全球耕地增长的热点区域主要分布在亚马逊林地、欧亚大草原和撒哈拉沙漠边缘。全球耕地减少的中心从欧洲转移到亚洲。由于迅速的城市化,亚洲耕地扩张侵占了大量农田。  相似文献   

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Journal of Geographical Sciences - Understanding the past variations in extreme drought is especially beneficial to the improvement of drought resistance planning and drought risk management in...  相似文献   

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归一化植被指数(NDVI)作为表征植被生长状况的关键性指标,能够有效的提供植被生长状况的信息。本研究基于1982–2015年哈萨克斯坦时间序列的GIMMS/NDVI数据,分析植被)生长的空间格局及变化趋势,研究结果表明:哈萨克斯坦自北向南分布着农田、草地、灌丛这三类主要的植被类型,呈明晰的地带性分布特征;植被指数由北到南逐渐降低,农田、草地和灌丛三类主要植被类型的NDVI均值水平依次为农田草地灌丛;1982–2015年间,NDVI呈现出先增长(1982–1992年)、再降低(1993–2007年)、然后又增长(2008–2015年)的变化趋势。NDVI显著下降的区域占土地总面积的24.0%,主要分布在西北部的农田与草地交错地带以及南部边缘的农田,草地退化面积占草地总面积的23.5%、农田退化面积占农田总面积的48.4%、灌丛退化面积占灌丛总面积的13.7%,植被改善的区域分布在中东部的农田以及农田与草地的交错带,显著提升的面积占土地总面积的11.8%。  相似文献   

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《Polar Science》2008,2(3):163-174
Isotopic analysis of the Martian lherzolitic shergottite Yamato 000097 yields a Rb–Sr age of 147 ± 28 Ma with an initial 87Sr/86Sr ratio of 0.710490 ± 0.000072, a Sm–Nd age of 152 ± 13 Ma with an initial ɛ143Nd-value of +11.7 ± 0.2, and a 39Ar–40Ar age of ∼260 Ma. The near concordance of these ages, in combination with the Rb–Sr and Sm–Nd initial isotopic signatures, suggests that Yamato 000097 crystallized from low Rb/Sr, light rare earth element depleted source materials ∼150 Ma ago. Although the obtained 39Ar–40Ar age is significantly higher than the Rb–Sr and Sm–Nd ages, Yamato 000097 shows little or no evidence of trapped Martian atmospheric 40Ar. The trapped 40Ar concentration of Yamato 000097 is similar to that of Zagami, suggesting that both basaltic and lherzolitic shergottites may have similarly inherited excess 40Ar from their magmas.The Rb–Sr and Sm–Nd ages, and initial 87Sr/86Sr and ɛ143Nd-values of Yamato 000097 and Yamato 793605 lie on the same isotopic ingrowth curves, suggesting that they came from very similar mantle sources. Allan Hills 77005 was also probably derived from the same source, but Lewis Cliff 88516 appears to be from a distinct but similar source. Yamato 000097 represents the most recent known magmatism from its source, and is the youngest Martian meteorite for which concordant Rb–Sr and Sm–Nd ages have been determined.  相似文献   

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Hengduan Mountains offer land space for a variety of ecological services. However, the sustainable development and management of land space has been challenged by increased human activities in recent years. This paper performs the spatial pattern analysis of the quantitative and structural changes of various landscapes at different altitudes, and uses the land use data in 1990, 2000, 2010 and 2015 to reveal how various land patterns have changed. The results show that, within the production-living-ecological space schema, the ecological space dominates Hengduan Mountains, while the production and living space was mainly distributed in south region. During 1990–2015, the production-living-ecological spatial changes had been gradually accelerated and the regional differences had become more prominent. The agricultural production space had continuously decreased by 1132.31 km2, and the industrial and mining production space had rapidly increased by 281.4 km2 during 1990–2015. The living space had steadily increased, and the ecological space had increased with fluctuations. The land space pattern in Hengduan Mountains was greatly restricted by the terrain, such as altitude and slope. The implementations of China Western Development Strategy and the Returning Farmland to Forest Program had favorably promoted the changes of land spatial pattern in Hengduan Mountains.  相似文献   

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