Environment and Planning B: Urban Analytics and City Science

A cellular automaton is specified to give a spatially detailed representation of the evolution of urban land-use patterns. Cell states represent land uses, and transition rules express the likelihood of a change from one state to another as a function both of existing land use in the 113-cell neighbourhood of the cell and of the inherent suitability of the cell for each possible use. The model is used to simulate the land-use pattern of Cincinnati, Ohio. The simulation results are realistic and sensitivity analysis shows that the predictions of the model are relatively accurate and reproducible, thus suggesting that cellular ast;automata-based models may be useful in a planning context.

Natural resources management typically requires prediction of environmental changes over large areas or long time periods. In the case of forest management, for example, decisions can affect timber production, water catchment properties, recreational values, aesthetic values, energy usage, or employment opportunities. Complex decisions can be assisted by effective presentation of the outcome of systems modelling. In this paper we describe the development of advanced visualisation techniques in combination with a geographic information system and resource modelling. Application potential is illustrated through examples in forest management and visual impact assessment. The emphasis is on provision of visual feedback on the outcome of decision options. The main interactive window allows three-dimensional movement of, or over, the management area based initially on imagery draped on a digital terrain model. Also on screen are menus or sliders which may control time, position along a line, or the values of data or modelling parameters including sliders for decision variables. As the time or the decision variables are altered by the user, the result is presented through replacement of textures in the three-dimensional view to represent the changes in land cover or other outcome. Initially the visualisation is based on prior modelling in a well-defined decision space. The system reads model output in ARC/INFO export format whereas interactive visualisation is based on the Silicon Graphics Performer toolkit.

Spatial composition can be viewed as computations involving spatial changes each expressed as s – f(a) + f(b), where s is a shape, and f(a) is a representation of the emergent part (shape) that is altered by replacing it with the shape f(b). We examine this formula in three distinct but related ways. We begin by exploring the conditions under which a sequence of spatial changes is continuous. We next consider the conditions under which such changes are reversible. We conclude with the recognition of emergent shapes, that is, the determination of transformations f that make f(a) a part of s. We enumerate the cases for shape recognition within algebras U_ij, 0 ≤ i ≤ j ≤ 3, and within Cartesian products of these algebras.

The principle of minimizing boundary materials is applied to an analysis of the shapes of houses and rooms. It is shown that rooms are in general configured by several parts of circular arcs. The activity-based criterion to maximize freedom of movement in small activity area is introduced. This criterion can be basically reduced to the minimization of wall length, with the modification that rooms tend to be allocated farther apart. Several remarks are made as to why we tend to favor rectangular rooms.

Traditional investment environment evaluation focuses on macrofactors, factors such as government stability, restrictions, and red tape. The introduction of GIS into this field provides investors and local government decisionmakers with more specific information on investment location. In this paper, a GIS-based multicriteria evaluation support system for investment evaluation is presented. The aim of the system is to develop an analysis environment to support various investment researchers and investors and to allow users with different experiences to find their own answers, which may vary. Criterion definition, management, evaluation scenario management, and user interface are four essential components of such a system. The support system is integrated with a GIS software package through a computer network facility. A case study on the Nanchang-Jiujiang industrial corridor is carried out to test the flexibility of the system.

Urban vegetation impinges upon the physical environment by positively enhancing the microclimate and air and water quality. On the other hand, changes to the physical environment as well as the socioeconomic conditions of urban dwellers affect the health of urban vegetation and species abundance and diversity. This two-way vegetation-environment dynamism makes urban vegetation an ideal meter to gauge the environmental health of cities. Although studies utilizing such a proposition exist with reference to the physical environment, the usefulness of vegetation in monitoring urban social change has received very little attention. In this study the author seeks to find whether changes in urban vegetation can be linked to urban social changes by using Detroit as a case study. Demographic trends in Detroit are analyzed in light of the increasing greenness in the city detected by recent satellite images. Robust relationships between greenness change and demographic factors associated with urban decay (population decline, an increase in poverty level, and an increase in vacant units) are found. Models built with a remotely sensed greenness change index and urban decay variables appear to be free of any serious bias. Tests for the validity of such models are also successful. It is concluded that vegetation trends could be used as indicators of urban socioeconomic changes. A vegetation-based urban environmental quality index could therefore be developed to monitor physical and social changes in cities.

Environmental planning in the Netherlands is in the process of integrating spatial planning and environmental policy, in an effort to develop and protect physical features which contribute to quality of life in urban areas. This is not an easy task, because spatial planning and environmental policy are often in conflict rather than being complementary. Spatial planning in the Netherlands has traditionally been a responsibility of local governments, while the national government has promulgated environmental policy, which local governments are expected to implement. However the approach to dealing with environmental issues has recently undergone rapid change, as these issues have become increasingly complex and with growing recognition that they are importantly related to public local development objectives. This has given rise to the realization that programmes for resolving environmental conflicts can no longer be solely the responsibility of the national government; that local governments are often in the best position to solve environmental-spatial conflicts that are unique in character. The shift in approach and responsibility is presented here in a policy-approach model. This change of policy is narrowing the previous gap between spatial planning and environmental policy in the Netherlands.

Most people value and enjoy the benefits that the use of their own car brings to their quality of life. These benefits are reflected in the increases in travel, the use of more resources, and the production of more pollution. However, this situation is not sustainable. In this paper the author argues the case for planning playing an instrumental role in achieving sustainability objectives in transport. It reviews the contributions that economics (pricing) and technological measures might have. The conclusion reached is that the scale of price increases required to achieve a reduction in car use will not be politically acceptable. Similarly, technological improvements may only give us a breathing space before more positive action is necessary. Even if the environmental problems created by the car are solved, there will always be the underlying problem of congestion. The only alternative is to travel shorter distances, to develop the potential for linking activities, and to use the car less—this is where planning has a key role.

Three main actions are proposed to avoid the need to travel. The first is the implementation of a set of development principles through examining the role that density and settlement size might have on urban sustainability. This issue is particularly important given the current debate at all levels in the United Kingdom over housing allocations and the possibility of a new generation of new settlements. The second action explores the concept of the social audit and the social costs associated with the closure of existing facilities and the opening of new facilities, many of which are inaccessible to those without a car. There have been savings to the provider of the facility through economies of scale, but additional costs have been transferred to the users of these facilities. The social audit would examine all the costs and benefits of these decisions, with a view to subsidy to prevent closure and a tax on greenfield developments to help pay for the redevelopment of brownfield sites within urban areas. The third action is to create quality neighbourhoods in cities to maintain and promote communities with high environmental quality and no congestion. It is only through maintaining and improving environmental quality that urban sustainability can be enhanced, as these locations must form the focus for development. They allow for the provision of clean public transport, they would promote walk and cycling, and they would reduce levels of car dependence.

Through analysis of two sets of regional plans prepared under cooperative and coercive intergovernmental mandates in Florida and New Zealand, this study examines variation in mandate design features and their influence on plan quality. New Zealand's cooperative mandate has greater flexibility and permits more discretionary action to regional councils, while Florida's coercive mandate emphasizes technical capacity building, strong but limited use of coercion and financial support. Key policy implications of this study concern the design of regulatory mandates, and how the two approaches can learn from one another. Florida's approach leads to stronger plan fact basis and regulatory policies in plans, but could benefit from New Zealand's key mandate strength of building subnational political commitment to advance plan-making. New Zealand's approach leads to strong goals, but lacks strengths of specificity in setting goals, technical capacity building, selected use of strong coercion and funding which are emphasized in Florida's mandate. Thus mandates that lead to high quality regional plans would represent a combination of the two approaches.