Ian D. Bishop

Prediction of scenic beauty using mapped data and geographic information systems

Abstract Public concern for the visual landscape has led to the widespread use of codified, replicable processes for assessing, documenting and predicting a landscapes scenic beauty. The work reported proceeds on the belief that estimates of the visual impact of landscape change should be based on its effect on locations, and not on specific circumscribed views. We argue that using the computational capabilities of a geographic information system (GIS), together with prediction equations based on assessment of video panoramas of locations affected by landscape change, more objective and cost-effective visual assessment and prediction procedures may be developed. The approacg employed is described. The validity of the results is assessed in terms of our ability to match both public and expert-based landscape assessment. Finally, some implications for future research of this type are considered.

Determination of thresholds of visual impact: the case of wind turbines

Visual impact assessment using GIS (geographical information system) based viewshed mapping is commonly employed on major projects. However, there is typically little analysis of the possible range of impact based on the size of the introduced landscape element, its contrast with the surroundings, or the effect of typical levels of atmospheric scattering on the perceived contrast. A landscape element which is increasingly the subject of aesthetic scrutiny and visual analysis is the wind-energy turbine or—when installed in large numbers—the wind farm. I take the wind turbine as my subject partly because of its recent significance and also because, as a moving element, it is a special case. I report an Internet-based experiment to determine the relative perceived size of a turbine, image analysis to determine its typical contrast level, and the effect of atmospheric scattering on this contrast. With these three factors and equations derived in an earlier study, estimates are made for the probability of turbine detection, recognition, and visual impact at distances up to 30 km.

Spatial-temporal model for demand and allocation of waste landfills in growing urban regions

Abstract Shortage of land for waste disposal is a serious and growing potential problem in most large urban regions. However, no practical studies have been reported in the literature that incorporate the process of consumption and depletion of landfill space in urban regions over time and analyse its implications for the management of waste. An evaluation of existing models of waste management indicates that they can provide significant insights into the design of solid waste management activities. However, these models do not integrate spatial and temporal aspects of waste disposal that are essential to understand and measure the problem of shortage of land. The lack of adequate models is caused in part due to limitations of the methodologies the existing models are based upon, such as limitations of geographic information systems (GIS) in handling dynamic processes, and the limitations of systems analysis in incorporating spatial physical properties. This indicates that new methods need to be introduced in waste management modelling. Moreover, existing models generally do not link waste management to the process of urban growth. This paper presents a model to spatially and dynamically model the demand for and allocation of facilities for urban solid waste disposal in growing urban regions. The model developed here consists of a loose-coupled system that integrates GIS (geographic information systems) and cellular automata (CA) in order to give it spatial and dynamic capabilities. The model combines three sub-systems: (1) a CA-based model to simulate spatial urban growth over the future; (2) a spread-sheet calculation for designing waste disposal options and hence evaluating demand for landfill space over time; and (3) a model developed within a GIS to evaluate the availability and suitability of land for landfill over time and then simulate allocation of landfills in the available land. The proposed model has been tested and set up with data from a real source (Porto Alegre City, Brazil), and has successfully assessed the demand for landfills and their allocation over time under a range of scenarios of decision-making regarding waste disposal systems, urban growth patterns and land evaluation criteria.

Assessing the demand of solid waste disposal in urban region by urban dynamics modelling in a GIS environment

The twentieth century saw a dramatic increase in the production of urban solid waste, reflecting unprecedented global levels of economic activity. Despite some efforts to reduce and recover the waste, disposal in landfills is still the most usual destination. However, landfill has become more difficult to implement because of its increasing cost, community opposition to landfill siting, and more restrictive environmental regulations regarding the siting and operation of landfills. Moreover, disposal in landfill is the waste destination method with the largest demand for land, while land is a resource whose availability has been decreasing in urban systems. Shortage of land for landfills is a problem frequently cited in the literature as a physical constraint. Nonetheless, the shortage of land for waste disposal has not been fully studied and, in particular, quantified. This paper presents a method to quantify the relationship between the demand and supply of suitable land for waste disposal over time using a geographic information system and modelling techniques. Based on projections of population growth, urban sprawl and waste generation the method can allow policy and decision-makers to measure the dimension of the problem of shortage of land into the future. The procedure can provide information to guide the design and schedule of programs to reduce and recover waste, and can potentially lead to a better use of the land resource. Porto Alegre City, Brazil was used as the case study to illustrate and analyse the approach. By testing different waste management scenarios, the results indicated that the demand for land for waste disposal overcomes the supply of suitable land for this use in the study area before the year 2050.

Spatial data infrastructures for cities in developing countries Lessons from the Bangkok experience

Abstract The cities of the developing world face major problems in managing growth and their urban infrastructure. The experiences of cities in the developed world have usually proved inappropriate in developing countries and consequently new and innovative solutions are continually being explored for these cities. Geographic information systems and the underlying spatial data infrastructures appear to offer significant potential to assist in managing human settlements in developing countries. In examining the status of spatial data infrastructures in developing countries, the first part of the paper compares cities in developing countries to those in the developed world. It then highlights issues facing developing countries in establishing spatial data infrastructures to support efficient urban land management. The paper describes the Bangkok Land Information System as an example of a city attempting to use spatial information technologies to manage the urban environment. This case study, together with the experience of the authors, are used to describe generic issues involved in the development of spatial data infrastructures for cities in similar socio-economic conditions. The paper provides a technical and institutional framework for the development of spatial data infrastructures for cities in developing countries. The paper concludes by suggesting that simple, low cost, project oriented, easily maintained and user-friendly spatial information technologies have the best chance of success.

Assessment of path choices on a country walk using a virtual environment

Virtual environments can provide landscape researchers new opportunities to explore aspects of landscape perception and response. A virtual environment requires a detailed 3D model of a place and the use of a high performance computer to allow people to explore it interactively. As with any new experimental tool, we should first establish the validity of the technique. This paper describes the process of model building for a section of the Dee valley in northeast Scotland, the development of software to support interactive exploration, and an experiment which was designed to answer some primary questions about validity and some secondary ones about local landscape preferences. The findings were encouraging for the further use of virtual environments and showed that people made choices in the virtual environment which fitted their stated preferences and were different from the choices other subjects made on the basis of still images.

Experiential approaches to perception response in virtual worlds

Abstract Analysis of public behaviour has been referred to as the experiential approach to landscape assessment. The approach has not been widely used because of the time and cost involved and the difficulty of controlling the many variables which influence real world behaviour. Developments in the construction and presentation of virtual environments suggest that it is time to reconsider experiential approaches to preference research rejected as too complex in the 1980’s. Some aspects of behaviour in the landscape can now be effectively observed in a computer generated world at reasonable cost and with more complete control of variables. This paper explores monitoring of movement and development in virtual worlds and presents two preliminary experiments concerned with movement choices. The options and difficulties for application in an urban design context are reviewed.

Linking objective and subjective modelling for landuse decision-making

Abstract This paper describes a landuse modelling approach developed for the Makiling Forest Reserve in the Philippines. The process includes application of the analytical hierarchy process (AHP) but extends this approach to include objective process based modelling – in the form of the universal soil loss equation (USLE) – in the subjectively oriented framework of AHP. A geographic information system was used for data assembly and to define decision zones and a PC based interface developed to accommodate interactive application of the AHP and USLE models. Having successfully combined the objective and subjective elements for evaluation of landuse alternatives, the paper explores the options for landuse allocation based on the suitability assessments of a participating decision group.

Assessment of Visual Qualities, Impacts, and Behaviours, in the Landscape, by Using Measures of Visibility

The application of information technology to landscape analysis dates back to the early work in computer-based mapping. Indeed, much of the early development of what became geographic information systems (GIS) and three-dimensional landscape simulation was undertaken by landscape architects. Mapping of viewsheds quickly became a key element of the landscape-planning process. The process was applied to determination of both view characteristics and potential visual impacts. The algorithms for viewshed analysis were incorporated into GIS products at an early stage in their evolution, but have evolved very little since despite the identification of significant potential enhancements. Extension of the simple binary mapping of GIS has therefore depended on specific developments by individual researchers. These GIS extensions have generated models of visual quality and visual impact using mapped variables. More recently it has become apparent that the essentially two-dimensional approach to view analysis afforded by GIS is inadequate in situations with strong three-dimensional elements. The upsurge in agent-based modeling has demanded a new standard in computer-based visual interpretation of landscape. Both the historic role of GIS-based visual modeling and the potential of 3D-based visual modeling are reviewed.

Predicting the scenic beauty value of mapped landscape changes in a mountainous region through the use of GIS

Planning frequently fails to include the valuation of public goods, such as scenic beauty. This can lead to negative economic impacts for a region over the longer term. Especially in mountainous regions such as the Alps in central Europe, which depend on tourist income, the change of landscape views through the development of facilities for recreation and tourism may negatively affect the tourism experience, and hence the economy. In this study we present a prototypical technique to predict preferences for views using geographic information system (GIS)-based variables. A three-dimensional GIS including the effects of slope, aspect, and distance, as well as the height of landscape features, is developed to calculate the proportion of land-cover areas that make up the view. A Web-based survey is used to gather data on scenic preferences for landscape changes in the region around Davos (Switzerland). Willingness-to-pay (WTP) responses are used to identify preferred landscapes. A forced-choice questionnaire asks participants to compare pairs of landscape photographs. Two original pictures were digitally altered to visually represent landscape change scenarios developed for the study area. The visual magnitudes of the different land-cover areas are found to be correlated with the WTP values expressed by the respondents. The relationship is used to predict changes in scenic values for another view in the region. The approach presented in this paper could be useful in regional planning to estimate the influence of view components on peoples preferences.