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基于DEM 的水系自动提取与分级研究进展 总被引：12，自引：0，他引：12
随着信息化技术的快速发展,基于DEM产品提取水系等数据已经变得不再困难,但是,目前无论在水系自 动提取方面还是自动分级方面,都存在很多需要改进之处。论文分析了自动提取河网水系与流域边界,以及河网水 系分级的研究进展,在此基础上总结了当前存在的问题：(1)水系自动提取中的洼地处理、平地区域流向处理等; (2)河网水系自动分级方法中的参数单一,准确性较差,并且缺少水系实体之间的互相关联关系等问题。在此基础 上,提出了基于地理特征建立水系分级模型以解决分级问题的构想。 相似文献
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Peter Crabb 《The Australian geographer》1988,19(1):64-88
Within the Murray‐Darling Basin lie Australia's most important water and land resources as well as some of the country's most serious resource management problems. This paper summarises the importance of the resource‐based industries, especially agriculture. The major agricultural and water resource problems are outlined, with most attention being paid to salinity. Critical to the problems and their solution are the institutional arrangements for the management of this large interstate river basin. The River Murray Waters Agreement, dating from 1914, has had limited success in tackling the basin's problems, because of its limited geographical and functional scope, especially in the area of water quality. The growing severity of the latter problems, especially salinity, resulted in the 1987 signing of the Murray‐Darling Basin Agreement to promote and coordinate the management of the basin's water, land and environmental resources. As it is concerned with the basin as a whole, its success is dependent on the full cooperation of the Commonwealth and three state governments involved. 相似文献
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Jeroen C. J. H. Aerts Gerard B. M. Heuvelink 《International journal of geographical information science》2013,27(6):571-587
Many resource allocation issues, such as land use- or irrigation planning, require input from extensive spatial databases and involve complex decisionmaking problems. Spatial decision support systems (SDSS) are designed to make these issues more transparent and to support the design and evaluation of resource allocation alternatives. Recent developments in this field focus on the design of allocation plans that utilise mathematical optimisation techniques. These techniques, often referred to as multi-criteria decision-making (MCDM) techniques, run into numerical problems when faced with the high dimensionality encountered in spatial applications. In this paper we demonstrate how simulated annealing, a heuristic algorithm, can be used to solve high-dimensional non-linear optimisation problems for multi-site land use allocation (MLUA) problems. The optimisation model both minimises development costs and maximises spatial compactness of the land use. Compactness is achieved by adding a non-linear neighbourhood objective to the objective function. The method is successfully applied to a case study in Galicia, Spain, using an SDSS for supporting the restoration of a former mining area with new land use. 相似文献
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开发区土地可持续利用系统的结构研究 总被引：7，自引：0，他引：7
在提出开发区土地可持续利用概念的基础上，分析了开发区土地可持续利用系统的结构，指出我国现有开发区土地利用系统的结构不合理是引发开发区土地利用问题的根源。实现开发区土地可持续利用，有赖于优化目前的结构，即对开发区土地利用系统的各要素进行优化重组，从而改革其功能，以解决开发区土地利用中出现的各类问题。最后对如何优化开发区土地利用系统的结构进行了初步探讨。 相似文献
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ENRICO PUPPO PAOLA MARZANO 《International journal of geographical information science》2013,27(2):139-161
Many problems of practical interest involve line-of-sight on a topographic surface. Some such problems can be successfully studied on the basis of the mutual visibility among a finite number of representative points. Such visibility problems can be formalized and resolved as graph problems. In this paper, we show that graph algorithms can be useful to find efficient solutions for discrete visibility problems in several cases. On the basis of results from the theory of complexity, we give some practical rules to apply such an approach. We further investigate the solution of some relevant visibility problems under this perspective. 相似文献
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Identifying the problem regions and regional problems, and thus improving regional policies, are crucial for the sustainable development of various economic entities. The coordinated development of industrialization, informatization, urbanization and agricultural modernization(hereinafter referred to as "Sihua") is not only a practical need but an important strategic direction of integrating urban-rural development and regional development in recent China, and it also provides a significant perspective for identifying problem regions and regional problems so as to improve the regional policies. This study mainly aims to: firstly, establish a comprehensive evaluation index system so as to explore the spatial pattern of coordinated development of Sihua in China at prefecture level; secondly, to develop an evaluation criteria system to identify the problem regions and regional problems from the perspective of coordinated development of Sihua. This paper comes first in the scientific community to evaluate the coordinated development state of Sihua in China at prefecture level and identify the problem regions and regional problems from the perspective of Sihua development by quantitative analysis. This study may benefit the improvement of regional policies and thus contribute to the sustainable socio-economic development of China. 相似文献
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中国大城市病典型症状诱发因素的实证分析 总被引：5，自引：0，他引：5
论文基于已有研究将大城市病细分为交通拥堵、资源短缺、环境污染3种典型症状,采用2013年全国204个地级市横截面数据,根据夜间灯光数据构建人口空间分布指标,首先运用OLS回归探讨城市规模、空间失衡、建设滞后、产业转型、体制弊病等5种主要致病因素对大城市病的影响;其次,建立门槛效应模型进一步考察不同因素与大城市病之间是否存在非线性关系。实证研究结果表明,大城市病作为一种“综合病”,具体到不同层面对应的主要致病因素也大相径庭。其中,城市总体规模较大、城区人口过度集中分布、交通基础设施不够完善等是造成交通拥堵的主要原因;大城市中并不普遍存在资源匮乏的问题,相反地,产业结构的改善、公共服务的增加、行政权力的集中均有助于吸引和调动资源;此外,不论是城区人口总量的增加,还是分布结构的集中化,均显著不利于消除环境污染,并且非农产业比重的上升和城市道路面积的扩张也会对城市生态环境系统造成破坏。 相似文献
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This paper addresses the issue of commuting patterns and problems to workplaces in the urban periphery of Singapore. It is based on a case study of journey-to-work patterns of employees of Singapore Airlines Limited (SIA). The company's headquarters is in Airline House which is situated in the eastern comer of Singapore, a location which suffers from accessibility problems. The paper focuses on mode choice in the journey-to-work and, by means of a questionnaire survey, examines commuting patterns of a sample of Airline House workers in terms of first, the characteristics of the different modes of transportation used; and second, the socio-economic characteristics of workers including factors such as income, gender, occupational status and age. This is followed by a discussion of the problems faced in the daily commutes of workers. Many of these problems such as inconvenient public transport services, traffic congestion and long transit times are representative of those of other peripheral workplaces in Singapore. Based on the findings of the case study, the paper discusses some policy implications of the government's planning efforts to decentralise office activities from the CBD to suburban regions. 相似文献
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Spatial optimization for regionalization problems with spatial interaction: a heuristic approach 总被引：2，自引：0，他引：2
Kamyoung Kim Denis J. Dean Hyun Kim 《International journal of geographical information science》2016,30(3):451-473
Spatial optimization techniques are commonly used for regionalization problems, often represented as p-regions problems. Although various spatial optimization approaches have been proposed for finding exact solutions to p-regions problems, these approaches are not practical when applied to large-size problems. Alternatively, various heuristics provide effective ways to find near-optimal solutions for p-regions problem. However, most heuristic approaches are specifically designed for particular geographic settings. This paper proposes a new heuristic approach named Automated Zoning Procedure-Center Interchange (AZP-CI) to solve the p-functional regions problem (PFRP), which constructs regions by combining small areas that share common characteristics with predefined functional centers and have tight connections among themselves through spatial interaction. The AZP-CI consists of two subprocesses. First, the dissolving/splitting process enhances diversification and thereby produces an extensive exploration of the solution space. Second, the standard AZP locally improves the objective value. The AZP-CI was tested using randomly simulated datasets and two empirical datasets with different sizes. These evaluations indicate that AZP-CI outperforms two established heuristic algorithms: the AZP and simulated annealing, in terms of both solution quality and consistency of producing reliable solutions regardless of initial conditions. It is also noted that AZP-CI, as a general heuristic method, can be easily extended to other regionalization problems. Furthermore, the AZP-CI could be a more scalable algorithm to solve computational intensive spatial optimization problems when it is combined with cyberinfrastructure. 相似文献
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日本的国土开发对中国西部大开发的启示 总被引：4，自引：1，他引：3
本文在评述和总结日本国土开发中所取得的成功经验基础上 ,提出了中国在西部大开发中需要注意的四个问题 :一是要制定明确的开发目标和切实可行的开发方式 ,并通过立法的形式保障开发计划的实施 ;二是有效发挥社会资本和民间资本对西部开发的作用 ;三是加大力度促进西部中小城市的发展 ;四是在西部大开发中处理好资源、环境和灾害等问题。 相似文献
13.
FDI对我国劳动力就业的影响 总被引：6，自引：0，他引：6
自上世纪90年代起，我国劳动就业问题日趋严重。劳动力总量供大于求，隐性失业和显性失业并存，结构性和区域性就业矛盾突出。积极有效地治理和解决就业问题已成为政府的当务之急。本文把FDI作为应对严峻的就业问题的有效措施之一，探讨了我国城乡严峻的劳动力就业压力，FDI的飞速发展及其对劳动力就业的重要贡献，加入WTO后FDI对我国劳动力就业可能产生的影响。 相似文献
14.
Qualitative Explorations in Health Geography: Using Pragmatism and Related Concepts as Guides 总被引：1，自引：0，他引：1
Malcolm P. Cutchin 《The Professional geographer》1999,51(2):265-274
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《The Journal of geography》2012,111(3):163-168
Abstract This paper explores the concept of relevancy in the context of an introductory physical geography course. The concern is with a relevant content and structure. Both are introduced through a problem-orientation. Current societal problems related to the physical environment are used to introduce students to conditions and processes involving environmental elements such as atmosphere, water, soil, vegetation, and topography. Because they are societal problems, the additional element, man, is included. The structure assumes a priori that the student has some prior knowledge of environmental problems. With a relatively high level of individual involvement, the student is asked to utilize this knowledge in learning about environmental processes and physical geographic concepts. Feedback from student to instructors is maximized through greater reliance on discussion groups, exercises, papers, and a problem-solving examination. In transmitting subject matter and environmental problems information, greater reliance is placed on readings and less on lectures. 相似文献
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Identifying the problem regions and regional problems, and thus improving regional policies, are crucial for the sustainable development of various economic entities. The coordinated development of industrialization, informatization, urbanization and agricultural modernization（hereinafter referred to as ＂Sihua＂） is not only a practical need but an important strategic direction of integrating urban-rural development and regional development in recent China, and it also provides a significant perspective for identifying problem regions and regional problems so as to improve the regional policies. This study mainly aims to： firstly, establish a comprehensive evaluation index system so as to explore the spatial pattern of coordinated development of Sihua in China at prefecture level; secondly, to develop an evaluation criteria system to identify the problem regions and regional problems from the perspective of coordinated development of Sihua. This paper comes first in the scientific community to evaluate the coordinated development state of Sihua in China at prefecture level and identify the problem regions and regional problems from the perspective of Sihua development by quantitative analysis. This study may benefit the improvement of regional policies and thus contribute to the sustainable socio-economic development of China. 相似文献
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当前我国农地整理有关问题探讨 总被引：6，自引：0，他引：6
耕地是土地的精华,保护耕地就是保护我们的生命线。随着经济的发展,耕地保护的形势日趋严重。如何保护耕地,怎样才能在耕地数量稳定的情况下,提高耕地对生存与发展的保障能力等已成为人们关注的焦点。文章讨论了农地整理中出现的耕地质量、生态环境等问题。并针对这些问题,提出了相应的解决对策。 相似文献
18.
干旱指数与旱灾测防系统 总被引：5，自引：1，他引：5
本文讨论了干旱过程系统，干旱指数与旱灾测防系统问题，提出用干燥度、旱灾指数和干旱度研究旱灾；用旱灾测防系统减消旱灾。指出了研究这一系统的中心问题是环境湿润状态和经济社会水分供需平衡的结构与动态；减消旱灾的关键是监测、预报与工程调控系统。它对减消旱灾、保护环境、发展经济社会有重要意义。 相似文献
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