Environment and Planning B: Urban Analytics and City Science

The dynamic nature of land qualities both in space and in time suggests that, whatever the stages of the development of an area, it is always crucial to assess land qualities in terms of their potential and suitability for specific kinds of land use on a sustainable basis. In this paper we demonstrate an integrated method of biophysical land-suitability assessment, which combines two basic land-evaluation principles: allowing trade-offs among evaluation criteria, and a limiting condition approach. Decision criteria consist mainly of biophysical parameters, based on internal and external groups of land properties. Internal variables include various physical and chemical characteristics of soils, whereas external variables are those of topographic attributes. A fuzzy set methodology was employed to calculate values of a membership function, MF (0 ⩽ MF ⩽ 1.0), of each land variable. These fuzzy membership values were then combined to produce land-suitability indices, LSIs (0 ⩽ LSIs ⩽ 1.0), which can be used to assess the potential of land for a nominated land-use type. The analysis procedure implements a convex combination, which permits trade-offs between criteria of the same group, and a multiplicative function, which takes no account of compensation between groups (internal and external variables). A limiting condition approach is also incorporated in this system to resolve shortcomings found when using a convex combination technique alone. The results show that LSIs are consistent with categorical classes generated from applying the well-established method based on the Food and Agriculture Organisation framework for land evaluation. However, the LSIs, as derived from a cell-by-cell operation, produce more detailed subdivisions of land in terms of their potential for a given purpose. The main advantages of using this model include: (1) it minimises subjectivity in the evaluation procedure; (2) it takes into account the combined effects of the factors considered, while preserving information on biophysical constraints for a given purpose; and (3) it is amenable to further computer-based applications, especially for use in geographical information systems.

The fields of spatial planning, geographical information systems (GIS), and information and communication technology (ICT) are all developing at their own pace and in different directions, thereby obstructing the widespread acceptance of GIS as an integral part of planning practice. In this paper I take a closer look at their divergence and outline the role that a planning support system (PSS) can play in bridging this growing gap. I consider the benefits of participatory planning and show how my prototype of a PSS can contribute to its success. To that end, the functionality of this PSS is described in the context of the initial experience with its application in a diversity of planning circumstances. Some conclusions are then drawn on how a PSS can overcome some of the barriers to GIS support within planning practice.

By using traffic analysis zones (TAZs), centroids, and a road network as the inputs, traffic demand modeling aggregates trips from the locations of individual tripmakers to TAZ centroids and estimates trips generated between TAZs on the network. Like spatial analysis, traffic demand modeling is subject to the modifiable areal unit problem (MAUP). In this paper we report the findings of a simulation study, which uses eleven zoning structures and two levels of network detail to assess the effects of TAZs, centroids, and network detail on statewide traffic demand modeling in Idaho. First, trips generated between smaller TAZs have shorter trip lengths, higher proportions of interzonal trips, more accurate estimated volume-to-ground-count ratios, and lower percentage root mean square errors (E_RMS) between estimated volumes and ground counts. Second, the effect of centroid locations is mixed and generally slight with small TAZs. Third, the level of network detail impacts E_RMS values in two ways: larger TAZs produce lower E_RMS values than smaller TAZs on the less detailed network, and the detailed network outperforms the less detailed network, regardless of the size of TAZs.

In this paper we propose a multiclass, multicriteria network equilibrium framework for urban location and transportation decisions in the Information Age, in which the advent of telecommunication networks may provide a substitute for physical transportation. The framework interprets the option of telecommuting as a transportation mode choice and considers three distinct scenarios: (1) residential locations are known, as well as the number of residents, and one seeks to determine their places of work, along with their optimal routes of travel; (2) places of employment are given and the numbers employed are known, but one wishes to determine their residential locations and their optimal travel routes; and (3) the total number of individuals are given and one seeks to determine their residential locations, their employment locations, as well as their optimal routes of travel between. We allow each class of decisionmaker to have his or her own set of criteria associated with the route and locational decisions. We identify the underlying network structures of the problems, derive the governing equilibrium conditions, and establish the equivalent variational inequality formulations. We provide qualitative properties and propose a computational procedure along with convergence results. We then apply the algorithm to a numerical example and its variants.

Sustainable construction has developed in the past few decades in the Netherlands to a mature subject of policy, research, and innovation. In the technological field the opportunities for sustainable construction seem to be unlimited. In practice, in the Netherlands, measures to give concrete form to sustainable construction are only scantily applied. The suspicion arises that it is not technical factors but institutional factors that underlie the fact that as yet sustainable construction has failed to force a definitive breakthrough. The authors review to what extent institutions that influence the decisionmaking of players in the building sector regarding whether or not to apply sustainable construction have hindered improvement in sustainable construction.

For various purposes, virtual city applications have been developed around the globe to provide users with online resources and services over the Internet. Following our research on the Sheffield Urban Contextual Databank (SUCoD) project, this paper presents an alternative framework for building virtual cities, which goes beyond conventional static urban modelling. A three-tier system framework is described in conjunction with the design and implementation of the SUCoD prototype. We demonstrate SUCoD's novel functionalities by showing that complex urban contextual information sets, including three-dimensional interactive models, multilayer interactive maps, and hypermedia documents, can be retrieved dynamically by user-specified urban contextual attributes, spatial locations, and boundaries. The three-tier framework also facilitates system development in an extensible way, allowing continuous parallel extensions of system functionalities, user-interface components, and contextual data resources. SUCoD's dynamic capabilities are considered crucial in its future uses for urban contextual modelling on demand in relation to the past, present, and future of the City of Sheffield.

Hedonic house price modelling has been used extensively in the valuation of locational externalities. However, the theory of how locational externalities impact upon house prices is not reflected in the traditional measurements of location used in these studies. The result is that many hedonic house price models suffer from parameter estimates that are either insignificant or counterintuitive. In this paper I attempt to move towards a more realistic valuation of locational externalities by examining the effects of location upon house prices from a geographical as opposed to a purely economic perspective. A multilevel conceptualisation is presented, which takes into account the spatial effects of locational externalities upon house prices. A location-sensitive GIS of Cardiff and a multilevel specification of the hedonic model is then used to model these effects. I conclude that a more realistic treatment of location is required if locational externalities are to be valued successfully.

The planning system that was formalised in Britain in the 1947 Town and Country Planning Act is distinctive for the way in which it explicitly nationalised the rights to future development and distinguished between physical development and land-use change. Contingent causes for these characteristics can be found in the experience of planning in the first half of the 20th century which in turn was developed from sanitary legislation of the 19th century. There are, however, more fundamental reasons for the way in which the British planning system was constituted. In this paper I argue that the nationalisation of development rights and the separation of land use from building have their conceptual roots in medieval property law. As a colonial state in the period after the Norman Conquest, England saw the imposition of feudal law in its purest form. In such a system, owners of land were denied absolute rights to property of the kind available under Roman law and its derivatives. Legal theorists developed the doctrine of the estate which gave concrete existence to the limited rights of all those with an interest in a given parcel of land (those with tenure). Present and future rights to use could be distinguished. This conceptualising of property interest was to have profound consequences not only for property relations but also for the emerging planning system in the 20th century. It created a system which gave the state unprecedented control over changes to land, but which also had some significant disadvantages.

We present models for the design of routes for transportation of loads that might become hazardous or obnoxious to the population living along these routes. We take into consideration the fact that the values of the properties that are close to the roads used for the transportation may decrease as a consequence of this activity. As opposed to the traditional approach, of minimizing the population along the routes, we propose to include a compensation cost as a direct cost of choosing the routes. This compensation could include, for instance, a reduction in property tax rates. Two formulations are presented, covering different patterns of effects on property values. As an example of application of the models, we provide some computational experience.