J. Gary Polhill

Agent-based land-use models: a review of applications

Agent-based modelling is an approach that has been receiving attention by the land use modelling community in recent years, mainly because it offers a way of incorporating the influence of human decision-making on land use in a mechanistic, formal, and spatially explicit way, taking into account social interaction, adaptation, and decision-making at different levels. Specific advantages of agent-based models include their ability to model individual decision-making entities and their interactions, to incorporate social processes and non-monetary influences on decision-making, and to dynamically link social and environmental processes. A number of such models are now beginning to appear—it is timely, therefore, to review the uses to which agent-based land use models have been put so far, and to discuss some of the relevant lessons learnt, also drawing on those from other areas of simulation modelling, in relation to future applications. In this paper, we review applications of agent-based land use models under the headings of (a) policy analysis and planning, (b) participatory modelling, (c) explaining spatial patterns of land use or settlement, (d) testing social science concepts and (e) explaining land use functions. The greatest use of such models so far has been by the research community as tools for organising knowledge from empirical studies, and for exploring theoretical aspects of particular systems. However, there is a need to demonstrate that such models are able to solve problems in the real world better than traditional modelling approaches. It is concluded that in terms of decision support, agent-based land-use models are probably more useful as research tools to develop an underlying knowledge base which can then be developed together with end-users into simple rules-of-thumb, rather than as operational decision support tools.

Ontologies for transparent integrated human-natural system modelling

We propose an approach to modular agent-based land use modelling, based on ontologies in their computer science sense: formal representations of conceptualisations. The approach is primarily aimed at addressing the issue of model transparency. Human-natural systems models involve large numbers of submodels, making them difficult to understand for those not involved in their construction. We show that using ontologies to represent the structure and state of a simulation model improves transparency in two ways: First, the information about the structure and state is decoupled from the simulation software and can be independently processed. Second, the logics on which ontologies are based reflect more commonsense understandings of the relationships among concepts than those of computer programming languages.

e-Social Science and Evidence-Based Policy Assessment

The PolicyGrid project is exploring the role of Grid, Semantic Web, and Web 2.0 technologies to support e-Social Science, with particular emphasis on tools to facilitate evidence-based policy making. In this article, we discuss the challenges associated with construction of a provenance framework to support evidence-based policy assessment. We then discuss ourSpaces, a virtual research environment for e-Social Science that uses the Web 2.0 paradigm as well as Semantic Grid technologies and which provides researchers with facilities for management of digital resources using a novel natural language interface.