共查询到20条相似文献，搜索用时 31 毫秒
1.
统一规格的1〖DK〗∶10000地形要素数据是1〖DK〗∶10000数据全国“一张图”的数据基础,也是促进国家与地方交换共享、测绘地理信息行业与其他行业的数据资源共享、协同更新和快速服务的必然要求。鉴于各生产单位的1〖DK〗∶10000地形要素数据由于坐标系统、要素分类代码、数据层命名及数据层数、要素属性项命名及定义、成图数据格式等的不一致,不利于实现全国测绘地理信息的跨界共享、有效利用,所以规范1〖DK〗∶10000地形要素数据的数据内容,统一1〖DK〗∶10000地形要素数据的数据规格,对尽早实现全国“一张图、一个网”的战略发展目标具有十分重要的意义。 相似文献
2.
Network Density and the Delimitation of Urban Areas 总被引：3，自引：0，他引：3
Giuseppe Borruso 《Transactions in GIS》2003,7(2):177-191
This paper examines network analysis for urban areas. The research is focused on the problem of definition and visualisation of network geography and network spaces at different scales. The urban scale of analysis is examined and different spatial indices are considered. The built environment of the city is considered as a reference environment for a road network density index. The latter is implemented in order to study the spatial interactions between network phenomena and spaces and to provide further elements for the analysis of urban shape. The study is focused in particular on understanding spatial patterns drawn by networks and in helping with the delimitation of city centres. Different approaches are used to obtain the two indices: a grid–based analysis and a spatial density estimator based on Kernel Density Estimation. The two methodologies are analysed and compared using point data for the urban road network junctions and street numbers as house location identifiers in the Trieste (Italy) Municipality area. The density analysis is also used on road network junctions' data for the city of Swindon (UK) in order to test the methodology on a different urban area. 相似文献
3.
Measuring segregation: an activity space approach 总被引：3，自引：0，他引：3
While the literature clearly acknowledges that individuals may experience different levels of segregation across their various
socio-geographical spaces, most measures of segregation are intended to be used in the residential space. Using spatially
aggregated data to evaluate segregation in the residential space has been the norm and thus individual’s segregation experiences
in other socio-geographical spaces are often de-emphasized or ignored. This paper attempts to provide a more comprehensive
approach in evaluating segregation beyond the residential space. The entire activity spaces of individuals are taken into
account with individuals serving as the building blocks of the analysis. The measurement principle is based upon the exposure
dimension of segregation. The proposed measure reflects the exposure of individuals of a referenced group in a neighborhood
to the populations of other groups that are found within the activity spaces of individuals in the referenced group. Using
the travel diary data collected from the tri-county area in southeast Florida and the imputed racial–ethnic data, this paper
demonstrates how the proposed segregation measurement approach goes beyond just measuring population distribution patterns
in the residential space and can provide a more comprehensive evaluation of segregation by considering various socio-geographical
spaces. 相似文献
4.
多源时空数据的地表分类信息挖掘 总被引：1，自引：0，他引：1
随着国土空间的发展,自然资源管理、国土空间规划等对于地表分类信息的需求日益增大,如何采用数据挖掘手段高效准确地获取地表分类信息成为目前重要的研究方向。本文在对多源数据进行分析研究的基础上,以地理国情监测、基础测绘、天地图等多源时空数据为数据源,参考第三次全国国土调查分类方案,综合采用多维度地表分类、语义规则映射、空间综合映射、多场景特征判断、分类权重判断、空间聚合分析等多种方法对地表分类信息进行挖掘。提出了一种汇聚多源数据优势的地表分类信息挖掘方法,对于丰富地表分类数据产品类型和信息的维度具有重要的意义。 相似文献
5.
Angelos Tzotsos Konstantinos Karantzalos Demetre Argialas 《ISPRS Journal of Photogrammetry and Remote Sensing》2011,66(1):2-16
In this research, an object-oriented image classification framework was developed which incorporates nonlinear scale-space filtering into the multi-scale segmentation and classification procedures. Morphological levelings, which possess a number of desired spatial and spectral properties, were associated with anisotropically diffused markers towards the construction of nonlinear scale spaces. Image objects were computed at various scales and were connected to a kernel-based learning machine for the classification of various earth-observation data from both active and passive remote sensing sensors. Unlike previous object-based image analysis approaches, the scale hierarchy is implicitly derived from scale-space representation properties. The developed approach does not require the tuning of any parameter—of those which control the multi-scale segmentation and object extraction procedure, like shape, color, texture, etc. The developed object-oriented image classification framework was applied on a number of remote sensing data from different airborne and spaceborne sensors including SAR images, high and very high resolution panchromatic and multispectral aerial and satellite datasets. The very promising experimental results along with the performed qualitative and quantitative evaluation demonstrate the potential of the proposed approach. 相似文献
6.
《The Cartographic journal》2013,50(1):25-40
AbstractMost European countries have a national topographic map series at 1:100 000 scale, but currently Great Britain does not. The history of mapping at or around 1:100 000 in Britain is described briefly and consideration given as to why such a scale would be appropriate for a national series of mapping aimed at tourist and leisure users. The main focus of the article is to review a series of 1:100 000 scale maps of two sample areas of Great Britain, produced in the style of various western European medium scale topographic maps. Two further design examples are produced combining desirable characteristics of the maps examined. The results show both that many of the designs translate well to 1:100 000 scale maps of the British landscape and that there is considerable potential for a topographic base at this scale providing a basis for a national series aimed at tourist and leisure users. 相似文献
7.
Isa Baud Monika Kuffer Karin Pfeffer Richard Sliuzas Sadasivam Karuppannan 《International Journal of Applied Earth Observation and Geoinformation》2010
Analyzing the heterogeneity in metropolitan areas of India utilizing remote sensing data can help to identify more precise patterns of sub-standard residential areas. Earlier work analyzing inequalities in Indian cities employed a constructed index of multiple deprivations (IMDs) utilizing data from the Census of India 2001 (http://censusindia.gov.in). While that index, described in an earlier paper, provided a first approach to identify heterogeneity at the citywide scale, it neither provided information on spatial variations within the geographical boundaries of the Census database, nor about physical characteristics, such as green spaces and the variation in housing density and quality. In this article, we analyze whether different types of sub-standard residential areas can be identified through remote sensing data, combined, where relevant, with ground-truthing and local knowledge. The specific questions address: (1) the extent to which types of residential sub-standard areas can be drawn from remote sensing data, based on patterns of green space, structure of layout, density of built-up areas, size of buildings and other site characteristics; (2) the spatial diversity of these residential types for selected electoral wards; and (3) the correlation between different types of sub-standard residential areas and the results of the index of multiple deprivations utilized at electoral ward level found previously. 相似文献
8.
月球地形制图是了解月球形貌构造,开展月球工程探测及科学研究的基础性工作。自从发射嫦娥一号月球探测卫星以来,中国正式步入月球与行星制图研究的行列。首先,回顾了国内外月球探测与地形制图的基本情况;然后,结合中国嫦娥工程中在月球地形制图领域的研究工作,从月球地形制图标准体系建设、月球地形制图产品研制、月球地形制图理论及技术研究3个方面介绍了中国在月球地形制图领域开展的研究进展和取得的初步成果;最后,总结了当前月球地形制图研究领域中存在的关键理论和技术难题,并探讨了下一步亟需开展的研究工作,可为中国未来的月球地形制图研究提供借鉴。 相似文献
9.
Simulating the dynamics and processes within a spatially influenced retail market, such as the retail gasoline market, is a highly challenging research area. Current approaches are limited through their inability to model the impact of supplier or consumer behavior over both time and space. Agent‐based models (ABMs) provide an alternative approach that overcomes these problems. We demonstrate how knowledge of retail pricing is extended by using a ‘hybrid’ model approach: an agent model for retailers and a spatial interaction model for consumers. This allows the issue of spatial competition between individual retailers to be examined in a way only accessible to agent‐based models, allowing each model retailer autonomous control over optimizing their price. The hybrid model is shown to be successful at recreating spatial pricing dynamics at a national scale, simulating the effects of a rise in crude oil prices as well as accurately predicting which retailers were most susceptible to closure over a 10‐year period. 相似文献
10.
本文从三生空间功能角度出发,融合多源地理数据建立了三生空间分类指标体系,并进一步顾及空间交互特征,建立了城市空间宜居性评价体系。以武汉市为例,对武汉市中心城区的三生空间格局进行了识别,并对该区域的宜居水平进行了评价分析。结果表明：①武汉市中心城区三生空间的总体配置不均匀,空间上呈现出生活空间中心聚集、生产空间四周分散、生态空间范围大但数量较少的分布格局;②武汉市三生空间混合度较低,大部分城市空间功能类型单一;③受邻近空间的影响,武汉市中心城区中,宜居度较高的区域集中在中心城区的边缘地带。 相似文献
11.
多源地理大数据为地理现象的分布格局、相互作用及动态演化提供了前所未有的社会感知手段。城市是人类活动最为集中的区域,产生了多种地理大数据,并支持对于城市空间的理解。城市内部的分异格局是城市研究和规划所要面对的重要议题,社会感知数据提供了从"人-地-静-动"4个维度刻画城市分异格局的途径。梳理了不同类型大数据对于表达这4个维度特征的支持,并借鉴"生态位"模型,通过一个实例研究展示了集成多源数据量化城市空间分异特征的应用,最后讨论了相关的理论问题。 相似文献
12.
Abstract A classification method was developed for mapping land cover in NE Costa Rica at a regional scale for spatial input to a biogeochemical model (CENTURY). To distinguish heterogeneous cover types, unsupervised classifications of Landsat Thematic Mapper data were combined with ancillary and derived data in an iterative process. Spectral classes corresponding to ground control types were segregated into a storage raster while ambiguous pixels were passed through a set of rules to the next stage of processing. Feature sets were used at each step to help sort spectral classes into land cover classes. The process enabled different feature sets to be used for different types while recognizing that spectral classification alone was not sufficient for separating cover types that were defined by heterogeneity. Spectral data included the TM reflective bands, principal components and the NDVI. Ancillary data included GIS coverages of swamp extents, banana plantation boundaries and river courses. Derived data included neighborhood variety and majority measures that captured texture. The final map depicts 18 land cover types and captures the general patterns found in the region. Some confusion still exists between closely related types such as pasture with different amounts of tree cover. 相似文献
13.
ABSTRACT This paper addresses warm season hydroclimatic variability in the southern Appalachian region of the southeastern U.S., where precipitation can vary as much as 127?mm or more, with maximum seasonal totals exceeding 736?mm in extreme cases. Despite the occurrence of droughts, floods, and their socioecological impacts, hydroclimate variability is still poorly understood. This study characterizes the regional scale variations in the hydroclimate by examining the daily distribution of precipitation patterns in different topographic environments. Parameter-elevation relationships on independent slopes model (PRISM) gridded precipitation estimates are used to identify the location and frequency of different types of rainfall events. Several types of clustering algorithms are used as a regionalization approach to define areas where the precipitation regime exhibits similarities in its frequency of occurrence. The results are compared with internal validation statistics and a visualization is used to assess how well the resulting hydroclimatic regions align with different topographic environments. This study reveals the intricate spatial footprint of dry and wet regimes and demonstrates how clustering applications can be used with gridded climate data to determine where extremes are most likely to develop across mountain catchments. 相似文献
14.
Liegang Xia Jiancheng Luo Weihong Wang Zhanfeng Shen 《Journal of the Indian Society of Remote Sensing》2014,42(3):505-515
This paper proposes an automatic framework for land cover classification. In majority of published work by various researchers so far, most of the methods need manually mark the label of land cover types. In the proposed framework, all the information, like land cover types and their features, is defined as prior knowledge achieved from land use maps, topographic data, texture data, vegetation’s growth cycle and field data. The land cover classification is treated as an automatically supervised learning procedure, which can be divided into automatic sample selection and fuzzy supervised classification. Once a series of features were extracted from multi-source datasets, spectral matching method is used to determine the degrees of membership of auto-selected pixels, which indicates the probability of the pixel to be distinguished as a specific land cover type. In order to make full use of this probability, a fuzzy support vector machine (SVM) classification method is used to handle samples with membership degrees. This method is applied to Landsat Thematic Mapper (TM) data of two areas located in Northern China. The automatic classification results are compared with visual interpretation. Experimental results show that the proposed method classifies the remote sensing data with a competitive and stable accuracy, and demonstrate that an objective land cover classification result is achievable by combining several advanced machine learning methods. 相似文献
15.
以不同分类法探讨SPOT与IKONOS两种卫星影像之分类准确度 总被引：2，自引：0，他引：2
遥感探测可应用于大尺度环境之研究、规划及经营管理，故为探讨自然资源动态变迁之良好工具，惟现行影像来源与分类方法众多，研究者如何视其需要选择最佳组合，实有探讨之必要。本研究以SPOT及IKONOS两种不同空间解析力之卫星影像为材料，配合不同分类方法探讨台湾地区垦丁公园不同植群社会之空间分布信息，其结果均证实可行。而由研究过程发现，不同影像使用不同分类方法，其分类准确度有所差异，其中IKONOS影像因具有较高之空间解析力，有时反而容易造成影像分类的误授、漏授；而绿色植生部分尚无法由卫星影像之波谱值完全区隔，因此分类之精度仍有待精进。就影像分类而言，良好的训练样区配合正确的分类方法，可迅速获得一定准确度以上之分类结果，惟有时限于分类别的影像波谱值过于接近及各种地形效应、辐射效应之影响，会造成影像分类结果有误授、漏授及破碎化之情形产生，若能有效克服此一问题，则影像分类之成果将可提高其实用性。 相似文献
16.
地理国情普查最主要的内容是地表覆盖分类与重要地理国情要素,其中地表覆盖主要基于遥感或航空影像影像进行分割、分类,解译出地表覆盖物的类型,以便从地理的角度进行统计分析。大比例尺地形图具有地表覆盖物与地理要素丰富信息的特点,本文结合生产实践探索出一套大比例尺地形图数据应用于地理国情普查的有效技术方法。 相似文献
17.
Jinjin Yan Abdoulaye A. Diakit Sisi Zlatanova Mitko Aleksandrov 《Transactions in GIS》2020,24(2):371-389
Outdoor navigation is widely used in daily life, but faces various issues related to the fidelity of outdoor navigation networks. For instance, agents (pedestrians) are often guided via unrealistic detours around places without clear paths (e.g., squares) or if there are vertical constraints such as overpasses/bridges. This is partly explained by the fact that the main sources of navigation networks in current outdoor navigation are two‐dimensional road/street networks. Utilizing a three‐dimensional space‐based navigation model, compatible with some indoor approaches, is a popular way to address the above‐mentioned issues. A 3D space‐based navigation model is generated by treating 3D spaces as nodes and the shared faces as edges. Inputs of this model are enclosed 3D spaces (volumes). However, outdoor spaces are generally open and unbounded. This article puts forward an approach to enclose outdoor spaces and mimic the indoor environments to derive a network based on connectivity and accessibility of spaces. The approach uses 2.5D maps and consists of three major steps: object footprint determination, footprint classification and space creation. Two use cases demonstrate the proposed approach. Enclosing outdoor spaces opens a new research direction toward providing seamless indoor/outdoor navigation for a range of agents. 相似文献
18.
刘君臣 《测绘与空间地理信息》2014,(7):164-166
省级测绘档案资料馆馆藏了该省内各市、县的1∶500,1∶1 000等大比例尺地形图数据,这些数据大多采用地方坐标系。由于城市大比例尺数据的空间参考多为地方坐标系,使得对大比例尺数据进行统一查询、统计、定位难以实现。本文提出由地方坐标系地形图数据的图幅号生成相应的结合表,并将其转换到国家坐标系,将国家坐标系下的大比例尺结合表叠加到国家基本比例尺地形图数据中,可快速查询、定位到需要的城市大比例尺数据。 相似文献
19.
北京市城市基本比例尺地形图的更新模式 总被引：1，自引：1，他引：0
基础测绘是国民经济和社会发展的一项基础性和公益性事业,广泛服务于经济建设、社会发展、国防建设和人们生活的各个领域.而基本比例尺地形图是基础测绘产品的重要组成部分.北京的城市信息化建设需要大量现势性强的基础地理信息数据.基本比例尺地形图的动态更新与维护是保证基础地理信息系统具有现势性和时态完整性的基础性、前提性工作,它不... 相似文献
20.
城市用地空间信息分类与数字重建——以长春百年城市内部用地变化为例 总被引：2，自引：0，他引：2
针对单一应用遥感影像难以进行城市内部用地结构分类以及高精度城市内部用地多期空间数据叠置分析中位置误差问题建立了基于"分层分类"与"对象分割"的城市内部用地空间信息数字重建方法。实现对特大城市产业用地(住宅、商业、工业等)以及交通、水系、生态绿地等不同功能结构用地的高精度监测以及历史演变过程的重建。综合集成SPOT5,1︰1万地形图、历史地图及城市规划图等辅助信息对长春城市1905年以来城市用地信息进行分类。研究表明,在专家知识参与下人—机交互解译,集成多源空间信息对实现高精度城市用地空间信息重建具有较高的应用价值,该方法不仅能提高城市用地分类精度而且能提高城市用地空间信息提取效率以及多期空间数据叠置分析的定位精度。 相似文献