共查询到20条相似文献，搜索用时 718 毫秒
1.
基于网络时空核密度的交通事故多发点鉴别方法 总被引：1，自引：0，他引：1
交通事故多发点是道路交通安全管理的重要治理对象,如何利用空间统计方法对其进行高效鉴别是研究热点。以华东某地为研究区域,以2013~2015年该研究区域的道路交通事故数据为研究对象,以时空道路网络为视角,通过路网匹配和路网裁剪形成事故时空子路段,提出一种基于交通事故场景的网络时空核密度估计值作为鉴别指标,用累计频率法和零膨胀的负二项回归模型确定鉴别阈值的事故多发点鉴别方法。 相似文献
2.
坡面天文辐射总量的椭圆积分模式 总被引：11，自引：1，他引：11
本文讨论了坡面天文辐射总量的计算方法，在坡面日出日没时角配置关系及其变化规律的基础上建立了椭圆积分模式，该模式可计算全球范围内任意坡向，坡度在任意时段内的坡面天文辐射总量。 相似文献
3.
以陕-甘天然气输气管道工程为例,根据黄土地区特征,经实地考察和有关资料分析,采用类比分析和事故树结构函数计算法,进行了黄土区输气管道工程环境风险因素识别和环境风险定性与定量分析;得出了不同区段环境风险指数和相对排序;提出了黄土区输气管道环境风险的管理措施与对策,为管道安全施工和运营提供了环境保护依据。 相似文献
4.
《Norsk geografisk tidsskrift. Norwegian journal of geography》2012,66(5):301-309
Many theoretical and practical works aim at describing the spatial structure of Europe, where spatial relations have undergone continuous change. The article gives an overview of models describing the spatial structure of Europe. The models' diversity is highlighted, without any claim to the completeness of the list of models discussed. The authors describe the economic spatial structure of Europe through bidimensional regression analysis based on a gravity model. With the help of the gravity model, they generate a spatial image of the economic spatial structure of Europe. With the images, the appropriateness of the models based on different methodological backgrounds can be justified through comparison with the authors' results. The authors aim to contribute to understanding the European economic spatial structure through a new methodological approach, rather than to create and show a new model that overwrites existing ones. 相似文献
5.
The central area of the Russian Plain received substantial amounts Cs-137 fallout as a result of the Chernobyl accident in 1986, with inventories exceeding 40 kBq m−2 in many of the areas close to Chernobyl. Concern over the longer-term fate of this contamination has focused attention on the need to predict the post-fallout redistribution of the radiocaesium and, thus, future changes in the spatial distribution of contamination in the landscape. Since radiocaesium reaching the land surface as fallout is rapidly and strongly adsorbed by soil and sediment particles, any attempt to predict its post-fallout redistribution must focus on erosion and sediment delivery processes and must rely heavily on a knowledge of the geomorphological processes involved. This paper reports a detailed investigation of post-fallout Cs-137 redistribution in the 2.18-km2 Lapki catchment in the Middle-Russian Upland, which has required consideration of soil erosion processes, sediment delivery pathways, sediment delivery ratios and sediment sinks. The time elapsed since the Chernobyl accident is currently insufficient to result in significant reduction of Cs-137 inventories in eroding areas, but areas of deposition on both the lower slopes and on the balka sides and bottoms are already marked by significant increases in Cs-137 inventories. The results obtained emphasise that any attempt to develop meaningful predictions of the longer-term redistribution of Chernobyl-derived Cs-137 fallout within the Russian Plain must be based on a sound and detailed understanding of the linkage between the slopes and the balka systems and the fate of sediment entering the balka systems. 相似文献
6.
中国山地垂直带的数字集成与基本规律分析 总被引：7，自引：2，他引：7
首次归纳出我国63类垂直带(包括31类基带)；在ArcGIS 8．3平台上,以山地垂直带谱“数字引擎”为内核,成功研制了“中国山地垂直带谱信息系统(1．0)”,将我国约239个山地垂直带谱进行了数字集成,使我们对我国垂直带谱数据的掌握从残缺上升为相对完备。该研究工作不仅为我国山地垂直带谱规律的数字分析提供了强大的手段,也为世界山地垂直带谱的数字集成提供了必要的理论和技术方法。还利用该系统,对重要垂直带界线如雪线、林线、高山草甸进行了空间规律分析。结果表明,除高山草甸经向变化缺乏明显规律外,其他垂直带界线的经、纬向变化的二次曲线(抛物线)模式比其他模式具有更高的相关系数。因而,抛物线模式应是我国山地垂直带宏观尺度上的基本空间模式。今后垂直带谱研究应在界线精度、带谱结构的地理学／生态学解释等方面继续深入。 相似文献
7.
北极海冰的大量融化,加速了北极航道开发和利用,对北极水域船舶事故风险管理提出了更高的要求。本文以2008—2017年的北极水域船舶事故数据为样本,运用数据挖掘技术和方法,对北极水域船舶事故进行了时空特征分析,并对船舶属性与事故属性之间的潜在映射关系进行了关联规则挖掘。结果表明:北极水域事故数逐年呈上升的趋势,事故主要发生在巴伦支海东部的俄罗斯摩尔曼斯克港口水域和挪威北部水域;北极水域严重事故受船舶总吨、船旗国、船舶类型、事故类型、事故水域等变量的影响,船舶尺度较大的船舶更容易造成严重事故;北极水域俄罗斯籍渔船的严重事故,很多是由机损事故引发的,但很少造成环境污染。研究结论可辅助海事管理部门和航运企业开展北极水域船舶事故预防和风险管理工作。 相似文献
8.
Sabrina Scherzer Nina Gunnerud Berg Haakon Lein 《Norsk geografisk tidsskrift. Norwegian journal of geography》2020,74(3):152-164
ABSTRACT Despite much attention paid to the topic of community in academic literature and policy documents, there is a relative lack of knowledge about what laypersons perceive as a local community. Based on data from a national survey, the authors examine how c.1400 Norwegians conceptualized local community – lokalsamfunn in Norwegian. They reveal some of the linguistic and conceptual aspects of local community as a term, in addition to tendencies and patterns among the survey responses. The respondents’ conceptualizations contained references to lokalsamfunn variously as a geographical area, people and relations, activities and involvement, attachment to place and people, and provider of local goods and services. Their main emphasis was on lokalsamfunn as a spatial unit. However, the responses contained relatively few references to the relational aspects of lokalsamfunn. The authors conclude that a common, lay understanding may be that lokalsamfunn is a vaguely defined but limited geographical unit filled with people who to varying degrees know each other and interact. Concerning policymaking aimed at fostering communal well-being, the authors hold that any community-based programming requires intricate knowledge of the people who form the community, since without community interaction and a degree of social cohesion any envisioned programmes may not succeed. 相似文献
9.
Yuk Yee Yan Department of Geography Hong Kong Baptist University Kowloon Tong Hong Kong 《地理学报(英文版)》1998,(3)
Ｉ．ＩｎｔｒｏｄｕｃｔｉｏｎＩｔｈａｓｌｏｎｇｂｅｅｎｒｅｃｏｇｎｉｚｅｄｔｈａｔｒｏａｄａｃｉｄｅｎｔｓａｒｅｔｈｅｒｅｓｕｌｔｏｆｔｈｅｃｏｍｂｉｎｅｄｅｆｅｃｔｓｏｆｂｅｈａｖｉｏｒａｌ,ｔｅｃｈｎｏｌｏｇｉｃａｌａｎｄｅｎｖｉｒｏｎｍｅｎｔａ... 相似文献
10.
《The Journal of geography》2012,111(2):376-383
Abstract The purpose of this paper is to examine a particular type of formal geographic region—the viticultural region—to promote an understanding of the geographical bases of wine production. The authors have found that the viticultural area is an excellent vehicle for teaching students how geographers construct and analyze regions. Although the wine industry in the United States is concentrated overwhelmingly in California and secondarily in a belt running from New York across Pennsylvania and into Ohio, most of the lower 48 states have at least one officially recognized viticultural area. The following problem has been developed to be used “as is” or to be modified for any state or region in the country. By the end of the problem, students have gained hands-on experience in defining regions, correlating physical geography with human activities, and thinking about the importance of place names and scale. 相似文献
11.
J. L. Mateos O. Novaro T. H. Seligman J. Flores 《Geophysical Journal International》1997,129(1):212-214
We show that most of the arguments in the above paper are either incorrect or irrelevant to the point the authors are trying to make. We show that their results have no bearing on the model proposed by our group, as they claim. They discuss the seismic response of a valley with a 2-D trapezoidal cross-section in a vertical plane, whereas we dealt with a closed basin with a 2-D cross-section but of arbitrary geometry and in the horizontal plane. Even more significantly, the width of the valley they use is much smaller than the wavelength of the horizontal P waves that can resonate, thereby precluding any possibility of them being trapped. Therefore, their arguments do not clarify the issue posed in the title of their article. 相似文献
12.
Max D. Woodworth 《The Professional geographer》2013,65(4):630-638
China's coal industry has been plagued by fragmentation among thousands of producers, low productivity, environmental damage, and high accident rates. Coal-industry reforms have sought a “strategic westward movement” through which to achieve resource consolidation under larger firms and upgraded production in northern and western China. This article examines Ordos Municipality and Yulin Municipality to assess the role of differently scaled political and economic processes that have driven a regional coal boom. It finds that the regional coal boom in north-central China discloses persistent difficulties in controlling producers and modernizing the sector. 相似文献
13.
ERLING SVERRE NORDØY 《Polar research》1995,14(3):335-338
An adult harp seal, caught by accident in a gill net during the peak of the seal invasions along the northern coasts of Norway (1986/87), was found to have eaten 2.466 kg of stones with masses up to 265 g. Different theories to why harp seals on occasion deliberately eat stones, with particular emphasis on the hypothesis that these may aid in the physical breakdown of fish flesh and hard fish bones, are discussed. 相似文献
14.
Dominika Studzińska Alena Sivkoz Stanislaw Domaniewski 《Norsk geografisk tidsskrift. Norwegian journal of geography》2018,72(2):115-126
Cross-border shopping and tourism are worldwide phenomena, appearing at any border with at least some degree of permeability. The authors investigate the range of cross-border shopping and tourism activities practised by Russians at two of the EU’s external borders, one between Finland and the Leningrad Oblast, and the other between Poland and the Russian exclave of Kaliningrad Oblast. The study is based on research conducted in the Polish–Russian and Finnish–Russian border regions between 2013 and 2015, when the authors held interviews, administered survey questionnaires, and engaged in participant observation. The information was supplemented with data from the Finnish and Polish Border Guard services. Based on the results of the fieldwork, the authors argue that cross-border shopping and tourism are often combined during the same trip, and thus constitute a specific form of cross-border activity. Their study sheds light on how cross-border shopping tourism depends on and is interconnected with more than just the factor of the non-availability of goods and services. They conclude that cross-border shopping at the Polish–Russian border and the Finnish–Russian border has become more like a Western European practice, namely shopping for pleasure. 相似文献
15.
《Norsk geografisk tidsskrift. Norwegian journal of geography》2012,66(5):287-304
ABSTRACTThe compact city is globally acknowledged as the most adequate urban model to encourage sustainable urban development. Its validity is often assumed, despite the lack of clarity on what such compactness entails. The knowledge gap is even wider regarding how different drivers and pressures influence the development of more compact cities. Therefore, the authors analyse indirect and underlying processes (drivers) and more direct events, actions, and processes (pressures) affecting compact city development. Since compact city driving forces are extensively influenced by local situations, their research focused on district-level case studies within the compact city of Barcelona Municipality. Mixed methods were used, and the authors used both qualitative and quantitative data. The results revealed that drivers and pressures can both support and counteract compact city qualities and therefore any intervention has to be tailored to local conditions. In particular, the results of the in-depth analysis of local pressures and their progression over time foster an understanding of context-related nuances, thereby shifting attention from taken-for-granted compact city qualities to the driving forces that produce beneficial compactness. The authors conclude that the diversity of drivers and pressures requires the involvement of a multiplicity of stakeholders and actors in urban planning, implementation, and management. 相似文献
16.
为探讨沙漠地区水泥混凝土路面温度梯度分布,提供最大温度梯度设计参数,根据气象学和传热学原理建立了层状路面结构体温度场数学模型,采用解析理论和Newton-Naphson迭代法推导出完全依赖于气候条件下非线性边界条件路面温度场计算方法。用该方法模拟了位于内蒙古锡林浩特沙漠地区试验路温度,温度最大误差不超过2℃,计算结果和实测值基本符合。在此基础上,研究了水泥混凝土路面温度梯度分布规律及其影响因素,结果表明:路面温度梯度沿深度非线性分布,板内温度梯度变化明显。最大温度梯度随面层导热系数和面板厚度增大而减小,导热系数和面板厚度每增加1 kcal.m-1.h-1.℃-1和1 cm,最大温度梯度分别减小约0.2～0.3 ℃.cm-1和0.025～0.052 ℃.cm-1。沙漠地区最大温度梯度设计值推荐为1.01～1.09 ℃.cm-1。 相似文献
17.
Miroslav Šifta Pavel Chromý 《Norsk geografisk tidsskrift. Norwegian journal of geography》2017,71(2):98-113
The aim in the article is to conceptualize the general foundations of research on the importance of regional symbolism in the process of region and regional identity formation. The article is founded on a critical analysis of works pertaining not only to the field of the new regional geography, but also to the field of regional marketing and/or branding, sociology, and semiology. The authors focus on meanings attributed to symbols and symbolism in literature, and observe which elements are viewed as regional symbols and how these symbols contribute to the process of regional development and institutionalization, especially in the formation of its symbolic shape. They examine the thematic and theoretical grounds, looking at identity, regional identity, and regional institutionalization. Next, regional symbols are defined and classified according to their types and forms, and their importance in the process of regional formation and institutionalization is discussed. The results show that symbols of any type can play an important role in a region’s marketing, and become the key image associated with a region. The authors conclude that regional symbols are a significant feature of the formation of a region and its identity, both outwardly (the external image of a region) and inwardly (concerning the inhabitants’ relationships with their region). 相似文献
18.
中国人口城市化的影响要素与空间格局 总被引：9，自引：3，他引：6
利用2000年第五次人口普查数据和相关统计资料对中国人口城市化的影响要素和空间格局进行分析和研究。从城市角度分析中国人口城市化的影响要素后发现:中国城市人口规模与经济实力要素、社会发展要素和消费要素显著相关,与经济结构要素相关性不显著;运用GIS技术分析中国人口城市化的空间格局发现:中国县级人口城市化空间格局存在明显的东北、中部和西南"三元"结构,省级人口城市化体现出"三区(即京津沪区、渝鄂区和藏新区)、三带(东部带、中部带和北部带)"的空间格局。 相似文献
19.
Current global urbanisation processes are leading to new forms of massive urban constellations. The conceptualisations and classifications of these, however, are often ambiguous, overlap or lag behind in scientific literature. This article examines whether there is a common denominator to define and delimitate–and ultimately map–these new dimensions of cityscapes. In an extensive literature review we analysed and juxtaposed some of the most common concepts such as megacity, megaregion or megalopolis. We observed that many concepts are abstract or unspecific, and for those concepts for which physical parameters exist, the parameters are neither properly defined nor used in standardised ways. While understandably concepts originate from various disciplines, the authors identify a need for more precise definition and use of parameters. We conclude that often, spatial patterns of large urban areas resemble each other considerably but the definitions vary so widely that these differences may surpass any inconsistencies in the spatial delimitation process. In other words, today we have tools such as earth observation data and Geographic Information Systems to parameterise if clear definitions are provided. This appears not to be the case. The limiting factor when delineating large urban areas seems to be a commonly agreed ontology. 相似文献
20.
《Norsk geografisk tidsskrift. Norwegian journal of geography》2012,66(4):199-210
The authors use the 2007 ISA virus outbreak in Chilean salmon aquaculture, coupled with insights from post-structural political ecology, as an opportunity to examine the institutional architecture and discursive hegemony of particular production strategies that silenced local experiences with the industry in favour of continuing exploitation. The authors argue that the case makes visible some of the generally relevant processes in which the generation of the crisis takes place within governance structures that involve few spaces of engagement for local actors to influence and participate in decision-making. Municipalities have few opportunities to shape the development of an industry with significant socio-economic impacts on their jurisdictions. Finally, the authors show how the crisis opens spaces of engagement for local actors and argue that sustainable governance of aquaculture depends on such spaces through which critical perspectives and warning signs can be communicated and negotiated, and through which local entrepreneurs can enter the value chain. 相似文献