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Fields as a framework for integrating GIS and environmental process models. Part 2: Specifying field variables 总被引：2，自引：0，他引：2
KAREN K KEMP 《Transactions in GIS》1996,1(3):235-246
In Part 1 of this paper, the concept of a field variable was described. In Part 2, the way in which a field variable might be specified is outlined. Field variables can be declared like other data types in any standard computing language. Specifications of field variables must include several special properties which are used to express the relationship between the physical field and the discrete data model. Field variable properties determine how the spatial data can be manipulated. For example, specifying a cellgrid spatial data model requires information about grid orientation and origin and the size of cells, while specifying a polygon data model requires information about the minimum distance over which variation is recorded. In either case, this information can be used to select appropriate conversion procedures between spatial data models using similarly specified conversion matrices and rules. The use of field variables has pedagogic as well as practical value. New operations allowed include field functions such as those for determining integrals, slope, and aspect, and reserved variables such as latitude and longitude. 相似文献
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基于GIS的贝叶斯统计推理技术在印度野牛生境概率评价中的应用 总被引：11，自引：0，他引：11
目前,ＧＩＳ技术已被广泛应用在野生动物生境研究中。但是,作为空间数据分析和处理工具,ＧＩＳ缺乏进行启发式推理的能力。因此,与擅长于此的贝叶斯统计推理技术相结合则是解决这一问题的重要途径。以西双版纳纳板河流域生物圈保护区为试验区,综合应用ＧＩＳ技术和多元统计技术建立印度野牛生境的两个逻辑斯蒂多元回归模型：趋势表面模型和环境模型,第一个模型的自变量是位置坐标,第二个模型的自变量是一组环境因子,然后应用贝叶斯统计合并这两个模型产生贝叶斯综合模型。结果表明,贝叶斯综合模型优于环境模型,可应用于野生动物生境概率评价。 相似文献
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Infestations of corn rootworms (Coleoptera: Chrysomelidae) create economic and environmental concerns in the Corn Belt region of the United States. To supplement the population control tactics of areawide pest management programs, we believe that a better understanding of the spatial relationships between biotic and abiotic or physical factors at the landscape scale is needed. Our research used several geographical information systems (GIS) and spatial analytical techniques to examine relationships between corn rootworm metapopulation dynamics, soil texture, and elevation. Within GIS, several spatially explicit procedures were used that include an interpolation technique, spatial autocorrelation analysis, and contingency analysis. Corn rootworm metapopulation distributions were found to be aggregated and related to soil texture and elevation. We review techniques and discuss our preferences for using particular spatially explicit procedures. The information derived from the spatial analyses demonstrates how GIS can be used in areawide pest management to provide inputs for spatially explicit models to predict future pest populations and formulate more well‐informed pest management decisions. The techniques described in this paper could easily be extended to study the spatial dynamics between other pest populations in agricultural landscapes. 相似文献
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An integration between a visual programming environment and GIS has been developed to create and run spatial models. The visual programming environment provides graphical objects to create flowchart-like models of spatial phenomena using GIS data. The integrated system is object-oriented and designed to lessen the technical burdens of GIS programming. The system capabilities are demonstrated using a hydrological model example, and the model execution speed is compared with an equivalent model implementation in a traditional raster-based modelling system. 相似文献
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An integrated data model in three dimensional GIS 总被引：2，自引：0，他引：2
GONG Jianya XIA Zongguo Professor National Laboratory for Information Engineering in Surveying Mapping Remote Sensing WTUSM Luoyu Road Wuhan China 《地球空间信息科学学报》1999,2(1):1-8
The current GIS can only deal with 2-D or 2.5-D information on the earth surface. A new 3-D data structure and data model need to be designed for the 3-D GIS. This paper analyzes diverse 3-D spatial phenomena from mine to geology and their complicated relations, and proposes several new kinds of spatial objects including cross-section, column body and digital surface model to represent some special spatial phenomena like tunnels and irregular surfaces of an ore body. An integrated data structure including vector, raster and object-oriented data models is used to represent various 3-D spatial objects and their relations. The integrated data structure and object-oriented data model can be used as bases to design and realize a 3-D geographic information system. 相似文献
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Integrating data on health outcomes with methods of disease mapping and spatially explicit models of environmental contaminants are important aspects of environmental health surveillance. In this article, we describe a modular, web‐based spatial analysis system that uses GIS, spatial analysis methods and software services delivered over computer networks to achieve this end. The Environmental Health Surveillance System (EHSS) is a prototype system that is designed to serve three purposes: a secure environment for producing maps of disease outcomes from individual‐level data while preserving privacy; an automated process of linking environmental data, environmental models, and GIS tasks like geocoding for the purposes of estimating individual exposures to environmental contaminants; and mechanisms to visualize the spatial patterns of disease outcomes via Web‐based mapping interfaces and interactive tools like Google Earth. 相似文献
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As an important GIS function, spatial interpolation is one of the most often used geographic techniques for spatial query, spatial data visualization, and spatial decision-making processes in GIS and environmental science. However, less attention has been paid on the comparisons of available spatial interpolation methods, although a number of GIS models including inverse distance weighting, spline, radial basis functions, and the typical geostatistical models (i.e. ordinary kriging, universal kriging, and cokriging) are already incorporated in GIS software packages. In this research, the conceptual and methodological aspects of regression kriging and GIS built-in interpolation models and their interpolation performance are compared and evaluated. Regression kriging is the combination of multivariate regression and kriging. It takes into consideration the spatial autocorrelation of the variable of interest, the correlation between the variable of interest and auxiliary variables (e.g., remotely sensed images are often relatively easy to obtain as auxiliary variables), and the unbiased spatial estimation with minimized variance. To assess the efficiency of regression kriging and the difference between stochastic and deterministic interpolation methods, three case studies with strong, medium, and weak correlation between the response and auxiliary variables are compared to assess interpolation performances. Results indicate that regression kriging has the potential to significantly improve spatial prediction accuracy even when using a weakly correlated auxiliary variable. 相似文献
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地理空间数据模型及其对地理对象-空间关系的描述是地理信息科学（GIS）理论与应用研究的核心内容。介绍和讨论了一种新的GIS空间数据模型—空间染色模型（spatial chromatic model,SCM）的结构、操作、应用及其在地理学上的含义。SCM的特点是其每个基础数据单元（细胞）具有一个唯一的编码,这些编码提供了面向各种GIS空间分析和运算的丰富信息。SCM的本质是一种基于实体第一性的相对性地理空间,它有助于从一个新的视角更加深入地理解地理实体-空间关系。 相似文献
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Along with rapid global urbanization, cities are challenged by environmental risks and resource scarcity. Sustainable urban planning is central to address the dilemma of economic growth and ecosystem protection, where the use of land is critical. Sustainable land use patterns are spatially explicit in nature, and can be structured and addressed using spatial optimization integrating GIS and mathematical models. This research discusses prominent sustainability concerns in land use planning and suggests a generalized multi‐objective spatial optimization model to facilitate conventional planning. The model is structured to meet land use demand while satisfying the requirements of the physical environment, society and economy. Unlike existing work relying on raster data, due to its simple data structure and ease of spatial relationship evaluation, this research develops an approach for identifying land use solutions based on vector data that better reflects the actual shape and spatial layout of land parcels as well as the ways land use information is managed in practice. An evolutionary algorithm is developed to find the set of efficient (Pareto) solutions given the complexity of vector‐based representations of space. The proposed approach is applied in an empirical study of Dafeng, China in order to support local urban growth and development. The results demonstrate that spatial optimization can be a powerful tool for deriving effective and efficient land use planning strategies. A comparison to results using a raster data approach supports the superiority of land use optimization using vector data as part of planning practice. 相似文献
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数码城市空间数据模型与可视化研究 总被引：9，自引：0，他引：9
提出了一种新的基于三维矢量图形、数字地面模型与数字地面正射影像相结合的数码城市空间数据模型，介绍了基于这一模型的软件平台原型－CCGIS，并对未来数码城市构建技术进行了分析与展望。 相似文献
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矢量与栅格集成的三维数据模型 总被引：6，自引：0，他引：6
以矿山地质为背景，深入分析三维空间信息系统所涉及到的空间对象以及它们之间的联系，提出了几种新的空间对象类型。探讨用矢量与栅格混合的数据结构，以及面向对象的数据模型来表达各类三维空间对象，以此作为设计和建立三维地理信息系统的基础 相似文献
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地理知识是通过对地理科学领域独特的背景、过程和结果进行解释而得到的知识。如何有效表达和共享地理知识是地理学研究和应用中的重要问题。本文首先将地理知识划分为3个层次,事实型知识、规则及控制型知识和决策型知识,分析了不同阶段地理语言对地理知识表达与共享的支持能力。对比地图和GIS语言,发现新一代地理语言—虚拟地理环境VGEs(Virtual Geographic Environments)能够较为全面地支持3个层次的地理知识。针对VGEs,从多个角度分析了其服务于地理知识表达与共享的能力,包括虚实结合理论、地理模型库及管理系统、动态可视化表达和异地协同工作环境。结合面向珠江三角洲地区空气质量研究问题的虚拟地理环境平台,对上述各方面进行了阐述。最后从地理知识生成、管理与应用角度对未来研究提出展望。 相似文献
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Representing Complex Geographic Phenomena in GIS 总被引：1，自引：0，他引：1
《制图学和地理信息科学》2013,40(2):83-96
Conventionally, spatial data models have been designed according to object- or field-based conceptualizations of reality. Conceptualization of complex geographic phenomena that have both object- and field-like properties, such as wildfire and precipitation, has not yet been incorporated into GIS data models. To this end, a new conceptual framework is proposed in this research for organizing data about such complex geographic phenomena in a GIS as a hierarchy of events, processes, and states. In this framework, discrete objects are used to show how events and processes progress in space and time, and fields are used to model how states of geographic themes vary in a space-time frame. Precipitation is used to demonstrate the construction and application of the proposed framework with digital precipitation data from April 15 to May 22, 1998, for the state of Oklahoma, U.S.A. With the proposed framework, two sets of algorithms have been developed. One set automatically assembles precipitation events and processes from the data and stores the precipitation data in the hierarchy of events, processes, and states, so that attributes about events, processes, and states are readily available for information query. The other set of algorithms computes information about the spatio-temporal behavior and interaction of events and processes. The proposed approach greatly enhances support for complex spatio-temporal queries on the behavior and relationships of events and processes. 相似文献
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基于GIS的开采沉陷空间建模及计算研究 总被引：4，自引：2，他引：2
本文针对开采沉陷地表移动变形计算问题,在GIS平台利用空间数据模型给出了预测计算中不同坐标系的转换公式及其空间数据库的构建,并讨论GIS与专业工程模型的耦合方法,提出了基于COM的模型耦合方法应用于系统的构架。实践证明,该方式下GIS与开采沉陷专业工程模型结合具有明显的优越性,对其他相关专业领域的耦合应用具有一定的借鉴意义。 相似文献
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Tara Sharma Jeff Carmichael Brian Klinkenberg 《Journal of the Indian Society of Remote Sensing》2005,33(2):353-363
The transition to agricultural sustainability involves difficult choices and an understanding of the complex trade-offs associated
with agricultural activities. Decision support tools and techniques assist in making the informed decisions for a transition
to sustainable agriculture. Georgia Basin — Quite Useful Ecosystem Scenario Tool (GB-QUEST) is a computer-based, user-friendly
tool that has been developed to look at the future sustainability scenarios of the Georgia Basin in British Columbia. The
objective of this paper is to describe the agricultural model that has been developed for implementation in GB-QUEST. We present
its framework, spatial methodology for land-use simulation, and the initial results of its application.
The agriculture model is a spatial model that examines the social, economic and environmental consequences of user-defined
agricultural development strategies. The model simulates changes in the Georgia Basin from the year 2000 to 2040 in decadal
steps. User choices of local and global development factors, along with their "worldview" choices, are important inputs in
the model that determine the effects on environmental and socio-economic systems. The model has two components — Generation
of land-use scenarios, and Development of Indicator models. The first component uses cell-based spatial algorithms to simulate
likely changes/conversions in land-use up to the year 2040. The approach used here integrates the functionality of Multi-Criteria
Evaluation (MCE) and Cellular Automata (CA) techniques in order to simulate the land-use conversions. It uses Geographic Information
Systems (GIS) and remote sensing techniques for creating, storing and deriving the data sets required for the model. The second
component develops the indicator models for relating scenario variables to socio-economic and environmental variables such
as physical and economic yields, economic operation costs and nutrient surplus per unit area. These indicator models are used
to evaluate land-use scenarios generated by the users. The model encourages understanding of sustainability, by allowing one
to explore different possible scenarios of the future for their environmental and socio-economic consequences. 相似文献
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面向对象的GIS结构设计 总被引：3，自引：0，他引：3
本文提出了一种以地理实体为中心加空间数据结构模型－面向对象的ＧＩＳ结构模型。在此基础上，讨论了利用规范关系存贮ＧＩＳ中的各种基本数据，以及用ＮＦ２（Ｎｏｎ－ＦｉｒｓｔＮｏｒｍａｌ－Ｆｏｒｍ）的嵌套结构描述和构造面向对象的几何数据，从而实现了面向对象的ＧＩＳ结构设计与管理，提高了ＧＩＳ系统的生命力，简化了系统的开发进程。 相似文献
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在GIS应用中,涉及到大量的模型应用,这些模型包括了利用GIS进行空间信息处理的大部分阶段中所用到的模型.模型处理以及分析结果往往是进行下一步应用的基础,因此模型处理结果的误差和不确定性制约了实际的GIS应用.影响空间数据处理模型的误差和不确定性的因素主要包括:定位和特征信息,制图,空间分析,空间数据库以及空间数据处理模型等所具有的误差和不确定性.主要分析了空间数据处理模型误差和不确定性的表达、来源以及分析方法. 相似文献