A large body of research has examined relationships between accessibility to green space and a variety of health outcomes with many researchers finding benefits in terms of levels of physical activity and relationships with levels of obesity, mental health, and other health conditions. Such studies often use spatial analytical techniques to examine relationships between distance to such spaces and health data collated at an individual survey respondent's home address or, more commonly, derived from area-based census measures summarised at a centroid. Generally, such measures are becoming more sophisticated and have moved on from the use of straightforward Euclidean-based measures to those based on network distance. However, few studies tend to use a combination of approaches or seek to establish the implications of incorporating alternative measures of accessibility on potential relationships. Using a database of green spaces (and associated attributes) and a detailed network dataset for the city of Cardiff, Wales, we examine the sensitivity of findings to the ways in which different metrics are calculated. This is illustrated by examining the variations in association between such metrics and a census-based deprivation index widely used in health studies to measure socioeconomic conditions. Our findings demonstrate that not only will the distances to green spaces vary according to the methodologies adopted but that any study that aims to investigate relationships with attributes of the nearest green space should acknowledge that matches may vary widely according to the techniques used. We conclude by warning against the use of inappropriate methodologies in examining access to green space which may directly influence directions (and levels) of association and hence may limit their relevance in wider geographical contexts.
1 February 2012 in International Journal of Geographical Information Science
Previous research has drawn attention to the importance of measuring accessibility to public transit services for transport planning and decision-making purposes and to the use of GIS to produce accessibility maps. Existing measures have been criticised for their lack of sophistication and reliance on simple operations such as Euclidean buffering. This article introduces an accessibility measure based on enhanced ‘floating catchment’ techniques, which have to date not been applied to measure access to public transport opportunities. We demonstrate that, after essential modifications to reflect the characteristics of transit service provision, this approach captures many detailed aspects of accessibility including proximity, the balance between service supply and demand, cumulative opportunity and temporal availability. We illustrate its application using a case study based in South Wales, integrating publicly available digital transport timetables and information on bus stop locations with geospatial analysis tools to provide a realistic appraisal of bus transit accessibility. Such measures could clearly form the basis of future studies of social exclusion and access to public transport opportunities. We conclude by drawing attention to the potential for including more intelligent demand-side and supply-side modelling inputs and by reiterating the policy importance of developing more accurate evaluations of the current and future state of the public transport network.
1 April 2006 in Waste Management & Research: The Journal for a Sustainable Circular Economy
Despite recent UK Government commitments’ to encourage public participation in environmental decision making, those exercises conducted to date have been largely confined to ‘traditional’ modes of participation such as the dissemination of information and in encouraging feedback on proposals through, for example, questionnaires or surveys. It is the premise of this paper that participative approaches that use IT-based methods, based on combined geographical information systems (GIS) and multi-criteria evaluation techniques that could involve the public in the decision-making process, have the potential to build consensus and reduce disputes and conflicts such as those arising from the siting of different types of waste facilities. The potential of these techniques are documented through a review of the existing literature in order to highlight the opportunities and challenges facing decision makers in increasing the involvement of the public at different stages of the waste facility management process. It is concluded that there are important lessons to be learned by researchers, consultants, managers and decision makers if barriers hindering the wider use of such techniques are to be overcome.