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271.
龙岗金龙顶子火山空降碎屑物数值模拟及概率性灾害评估   总被引:1,自引:0,他引:1  
空降碎屑物为爆炸式火山喷发产生的一种重要的灾害类型,数值模拟已成为一个快速有效地确定火山灰扩散和沉积范围的方法。本文根据改进的Suzuki(1983)二维扩散模型,编写了基于Windows环境下的火山灰扩散程序。通过对前人资料的分析,模拟了龙岗火山群中最新火山喷发——金龙顶子火山喷发产生的空降碎屑物扩散范围,与实测结果具有很好的一致性,证实了模型的可靠性和参数的合理性。根据该区10年的风参数,模拟了7021次不同风参数时金龙顶子火山灰的扩散范围,以此制作了火山灰沉积厚度超过1cm和0.5cm时的概率性空降碎屑灾害区划图。本文的研究可为龙岗火山区火山危险性分析和灾害预警与对策提供重要的科学依据。  相似文献   
272.
This study contributes to the literature on applied urban geography by examining spatial patterns and processes of changing racial/ethnic diversity within the intra-urban context of Knoxville metropolitan statistical area. Knoxville embraces a diverse economic set up with opportunities in high-tech research and development, manufacturing, tertiary/service-sectors, construction, as well as entertainment industry. This serves well for its continued population growth, including minorities during 1990–2009. This paper explores how the neighborhood-level socioeconomic, demographic, and built-environment characteristics relate to tract-level racial/ethnic diversity, measured by multi-group diversity score and its components. Tools such as isarithmic surface density maps, correlations, principal components and regression analyses are used to examine processes of change. Results indicate that diversity in 1990 associates with negative change whereas diversity in 2000 associates with positive change. Though overall diversity sprawls and increases during 1990–2009, diversity among non-White declines during 2000–2009 and shows spatial confinement. Regressions suggest complicated mosaics of changing neighborhoods, providing evidence of invasion-succession, filtering and resurgence of ethnic-enclaves in specific neighborhoods. Concerning the six counties of the MSA, Knox is the most diverse whereas Union the least, though the share of Hispanics tops in Loudon and Asians in Knox. In terms of strategic planning, findings from this research can be used in creating equitable and sustainable urban communities that can improve the overall well-being of people by reducing racial/ethnic and socio-economic disparities that might occur as undesirable consequences of fast increasing diversity.  相似文献   
273.
Abstract

Limitations of the current land records systems in Belize, Central America, led leaders of the Ministry of Natural Resources to initiate this feasibility study for a computer-aided land information system (LIS). Land records in Belize have been based on the British Torrens land tenure system, which maintains five sets of records along with informative maps. One paper file is maintained for each title application and records are continually circulated between seven locations throughout the country, resulting in up to 3 years to complete the process of title registration. A LIS will permit quick access to land records and eliminate most of the current problems, and will merge with a geographic information system being developed for Belize.  相似文献   
274.
Distances from points to closest shorelines in a given direction are used, for example, in some models for estimating wave exposure. Such distances, also called fetch lengths, can be determined using standard geographic information systems. However, performance may be a problem if these distances are required for a great number of study points. Two new algorithms for determining fetch lengths for study points in the same directions are presented in this paper. It is assumed that the two‐dimensional map is stored in vector format, i.e. shorelines of islands and mainland are stored as polygons. The first algorithm works on a set of undirected line segments derived from the shoreline polygons. The other works on a raster representation of the map. The algorithm saves memory by postponing the rasterisation until necessary. Both of the new algorithms have superior efficiency to a previously reported algorithm when the number of study points is large.  相似文献   
275.
This study compares two types of intermediate soft-classified maps. The first type uses land use/cover suitability maps based on a multi-criteria evaluation (MCE). The second type focuses on the transition potential between land use/cover categories based on a multi-layer perceptron (MLP). The concepts and methodological approaches are illustrated in a comparable manner using a Corine data set from the Murcia region (2300 km2, Spain) in combination with maps of drivers that were created with two stochastic, discretely operating, commonly used tools (MCE in CA_MARKOV and MLP in Land Change Modeler). The importance of the different approaches and techniques for the obtained results is illustrated by comparing the specific characteristics of both approaches by validating the suitability versus transition potential maps to each other using a Spearman correlation matrix and, between the Corine maps, using classical ROC (receiver operating characteristic) statistics. Then, we propose a new use of ROC statistics to compare these intermediate soft-classified maps with their respective hard-classified maps of the models for each category. The validation of these results can be beneficial in choosing a suitable model and provide a better understanding of the implications of the different modeling steps and the advantages and limitations of the modeling tools.  相似文献   
276.
Maps designed for and used by sighted audiences benefit from map symbol standardization and convention but, with very limited exception (most notably two European projects), neither standardization nor convention guides the design and use of symbols for tactile maps. In this project, we developed and field tested symbolization for and use of tactile street maps. The development process included consultation with the literature as well as with field experts (orientation and mobility teachers, Braillists, and teachers working with students who are blind or have low vision). Following development, we undertook a three-year field testing and validation phase, in which we conducted pilot testing and formal testing with travelers who are blind or have low vision. Research results reveal not only a discriminable and useful tactile symbol set but also environmental feature use by travelers who are blind or have low vision.  相似文献   
277.
Mental and sketch maps have a long tradition in modern geography. Little theoretical and methodological distinction has been made, however, between different hand mapping approaches. Mental maps emerged from behavioral geography of the spatial science tradition as a technique to understand human behaviors based on peoples’ perceptions of their spatial environment. More recently, sketch maps have been used in participatory and qualitative geographic information systems (QGIS) to develop cartographies of group and individual spatial narratives. They are a tool that helps achieve QGIS's objectives of collecting unique spatial data of individual experiences, visualizing socio-spatial processes, breaking down particular barriers of positionality in research, and developing new uses of GIS. Two case studies illustrate the use of sketch maps in research, including a project examining job accessibility among working poor individuals and a study of the experiences of fear and safety in public spaces among lesbian, gay, bisexual, and transgender community members. Sketch maps in QGIS have many methodological merits. They add an invaluable dimension to the qualitative interview process, offer countermapping perspectives, generate detailed spatial information of individuals, and facilitate data interpretation.  相似文献   
278.
This paper argues cognitive mapping is a learning process that can be simulated by a self-organizing neural network. The learning of city locations was considered in two studies. One study focused on the learning of city locations on four continents. Results indicated the neural network aligned the cities producing systematic errors similar to those in human cognitive maps. A second study had a neural network learn a biased sample of city locations in the United States. Results indicated a non-linear relationship between cognitive and physical distances. Self-organized cognitive maps naturally produce this non-linear relationship when information from more than one scale is mapped into one space.  相似文献   
279.
Book Reviewed in this article:

Main Street: Northeastern Oregon: The Founding and Development of Small Towns. Barbara Ruth Bailey.

Food Politics: The Regional Conflict. David N. Balaam and Michael J. Carey, eds.

The International Economy and Industrial Development: Trade and Investment in the Third World. R. Ballance, J. Ansari and H. Singer.

Neighborhoods in Urban America. Ronald H. Bayor, ed.

The English Heartland. By Robert Beckinsale and Monica Beckinsale.

Regional Dimensions of Industrial Policy. Michael E. Bell and Paul S. Lande, eds.

Tension Areas of the World. D. Gordon Bennett, ed.

Latin America: an Introductory Survey. B. W. Blouet and O. M. Blouet, eds.

Integration and Division: Geographical Perspectives on the Northern Ireland Problem. Frederick W. Boal and J. Neville H. Douglas, eds.

Energy and Land Use. Robert W. Burchell and David Listokin, eds.

Slopes and Weathering. Michael Clarke and John Small.

Alaska's Rural Development. Peter G. Cornwall and Gerald McBeath, eds.

The Politics of Park Design: A History of Urban Parks in America. Galen Cranz.

World Congress on Land Policy, 1980, Proceedings. Matthew Cullen and Sharon Woolery, eds.

Oregon Divided: A Regional Geography. Samuel N. Dicken and Emily F. Dicken.

Urban Food Marketing and Third World Rural Development. T. Scarlett Epstein.

South Africa: Spatial Frameworks for Development. T. J. D. Fair.

Institutions and Geographical Patterns. Robin Flowerdew, ed.

Industrialization of U.S. Agriculture, An Interpretive Atlas. Howard F. Gregor.

Planning Theory: Prospects for the 1980s. Patsy Healy, Glen McDougall and Michael J. Thomas, eds.

Neighborhood Mobilization: Redevelopment and Response. Jeffrey R. Henig.

The American Urban System: A Geographical Perspective. R. J. Johnston.

Climate, History and the Modern World. Hubert H. Lamb.

Climate and History: Studies in Past Climates and Their Impact on Man. T. M. L. Wigley, M. J. Ingram and G. Farmer.

China: Railways and Agricultural Development, 1875–1935. Ernest P. Liang.

A Desirable Energy Future—A National Perspective. Robert S. Livingston, T. D. Anderson, T. M. Besmann, M. Olszewski, A. M. Perry, and C. D. West.

Topothesia: Essays Presented to T. S. Ó Máille. B. S. Mac Aodha, ed.

Transportation for the Poor: Research in Rural Mobility. Hal S. Maggied.

Land Uses in American Cities. Harold M. Mayer and Charles R. Haves.

Industrial Organisation and Location. Philip McDermott and Michael Taylor.

Human Adaptability: an Introduction to Ecological Anthropology. Emilio F. Moran.

Regional Analysis and the New International Division of Labor. Frank Moulaert and Patricia W. Salinas, eds.

The Nuclear War Atlas. Victoriaville, Quebec, Canada:

Urbanization and Environmental Quality. Isao Orishimo.

The Garden of Eden: The Botanic Garden and the Re-Creation of Paradise. John Prest.

Earthfire, The Eruption of Mount St. Helens. Charles Rosenfeld and Robert Cooke.

Contest for the South China Sea. Marwyn S. Samuels.

The Future of the Wetlands: Assessing Visual-Cultural Values. Richard C. Smardon, ed.

Tucson: the Life and Times of An American City. C. L. Sonnichsen.

The Geography of Multinationals. Michael Taylor and Nigel Thrift, eds.

Impact of Marine Pollution on Society. Virginia Tippie and Dana Kester.

Reviving the Industrial City: the Politics of Urban Renewal in Lyon and Birmingham. Jerry A. Webman.

Andean Reflections: Letters from Carl O. Sauer While on a South American Trip under a Grant from the Rockefeller Foundation, 1942. Robert C. West, ed.

Cartographic Drawing with Computers. P. Yoeli.  相似文献   
280.

The degree to which people judge the change in transit service level as service connectivity changes is assumed to vary with total transfer waiting time. An experiment was devised to collect measures of cognized connectivity of intercity transit services in relation to transfer time, and cognitive scalar values were consequently derived. An inverse relationship was found between cognized service level and connectivity; cognized transit level decreased at a decreasing rate. An analysis of the bus-service network in the Israeli Galilee region suggests the appropriateness of cognitive scalars for measuring the internodal accessibility of public transport services.  相似文献   
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