摘要:

This paper evaluates the representational nature (as opposed to technical merits) of object-orientation, particularly its strengths and weaknesses, in the context of modelling mobile objects. The evaluation is important amidst the development of object-oriented GIS given that the object-orientation paradigm is not grounded in spatial disciplines. The discussion is illustrated by a case study that uses an object-oriented GIS framework to model the individual fish movement and growth in a heterogeneous aquatic environment.

ISSN:1365-8816    

DOI:10.1080/136588100424936

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

This paper reports on an attempt to combine neo-classical urban economic theory with complex systems methods. The innovative feature of our model from the point of view of conventional economic theory lies in its explicit treatment of spatial relationships and time sequence. From the perspective of raster or cellular GIS models of urban processes, the work is innovative in that it replaces the more usual heuristic cell-transition rules with micro-economic theory. The mix of modelling paradigms is not unproblematic, however, and we discuss the challenges encountered at this research frontier. These notwithstanding, our hybrid model has the potential to be used as a GIS-based laboratory for exploring micro-economic propositions, particularly those relating to urban processes that are path dependent. The version of the model reported simulates spatially equilibriated path dependent futures of a city governed by local development decisions that are at partial equilibria in the neo-classical sense. Two simulations are described which permit visual and economic exploration of (a) an explicitly spatial version of the economic theory of externalities and (b) a new theory of densification. The dual paradigm (Cellular Automata-neo-classical economics) leads to an interesting class of simulations in terms of stability. Economically our simulated cities become increasingly efficient, in terms ofprivateandsocial product. The long-run economic equilibrium is achieved by many individually efficient negotiations based only on local information. There is no parallel long-runspatialequilibrium however. The spatial configuration of land uses is constantly shifting as a result of randomness in the land use bidding process. The spatial instability is, however, limited by the self-organised drive for greater overall economic efficiency. In economic terms, the model's spatial instability represents random re-allocation of land-use within a set of Pareto-efficient spatial configurations - an intriguing result that we intend to follow up in future work.

ISSN:1365-8816    

DOI:10.1080/136588100424945

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

This paper develops an interactive approach for exploratory spatial data analysis. Measures of attribute similarity and spatial proximity are combined in a clustering model to support the identification of patterns in spatial information. Relationships between the developed clustering approach, spatial data mining and choropleth display are discussed. Analysis of property crime rates in Brisbane, Australia is presented. A surprising finding in this research is that there are substantial inconsistencies in standard choropleth display options found in two widely used commercial geographical information systems, both in terms of definition and performance. The comparative results demonstrate the usefulness and appeal of the developed approach in a geographical information system environment for exploratory spatial data analysis.

ISSN:1365-8816    

DOI:10.1080/136588100424954

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

Temporal limitations of GIS databases are never more apparent than when the time of a change to any spatial object is unknown. This paper examines an unusual type of spatiotemporal imprecision where an event occurs at a known location but at an unknown time. Aoristic analysis can provide a temporal weight and give an indication of the probability that the event occurred within a defined period. Visualisation of temporal weights can be enhanced by modifications to existing surface generation algorithms and a temporal intensity surface can be created. An example from burglaries in Central Nottingham (UK) shows that aoristic analysis can smooth irregularities arising from poor database interrogation, and provide an alternative conceptualisation of space and time that is both comprehensible and meaningful.

ISSN:1365-8816    

DOI:10.1080/136588100424963

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

The analysis of local spatial autocorrelation for spatial attributes has been an important concern in geographical inquiry. In this paper, we propose a concept and algorithm ofk-order neighbours based on Delaunay's triangulated irregular networks and redefine Getis and Ord's (1992) local spatial autocorrelation statistic as Gi(k) with weight coefficient wij(k) based onk-order neighbours for the study of local patterns in spatial attributes. To test the validity of these statistics, an experiment is performed using spatial data of the elderly population in Ichikawa City, Chiba Prefecture, Japan. The difference between the weight coefficients of thek-order neighbours and distance parameter to measure the spatial proximity of districts located in the city centre and near the city limits is found by Monte-Carlo simulation.

ISSN:1365-8816    

DOI:10.1080/136588100424972

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

Snow courses that measure snow water equivalent (SWE) are clustered and limited in areal coverage in Idaho. This study used a cell-based geographic information system and multiple regression models to construct SWE surfaces from the snow course data by month (January to May) and by watershed. SWE was the dependent variable and location and topographic variables derived from a digital elevation model were used as the independent variables. Multiple regression performed better than the traditional interpolation methods for SWE estimation. The estimated SWE surface can be displayed at different spatial scales through neighbourhood operations, or used directly as a map layer for hydrologic modelling.

ISSN:1365-8816    

DOI:10.1080/136588100424981

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor