A generic integrated spatial decision support system for urban and regional planning

Abstract

The proposition that land use dynamics are complex and exhibit self-organising behaviour may seem at odds with the prima facie assumption that planners and policy-makers have a decisive influence on future land use. In reality, this is not a contradiction, but rather a challenge for model developers to recognize disparate types of drivers and to look at autonomous behaviour and (spatial) planning as an integral part of land use dynamics. Furthermore, experience learns that in order to support decision making and/or policy analysis we have to bridge the science-policy gap by ensuring that i) models incorporate policy-relevant drivers and provide policy-relevant output in a comprehensible form, and ii) buy-in from users is achieved by involving them in the development process. This paper presents a generic integrated spatial decision support system (ISDSS) for simulating urban and regional dynamics. The system aims to support long-term integrated policy development and planning by taking into account social, cultural, environmental and economic developments in an integrated fashion. It provides an easy-to-use interface targeting both policy analysts and scientists. The system is built using a software environment for dynamic spatial modelling and includes a library with models from various disciplines: economics, demographics, regional interaction, land use and transport. It is generic enough to be configured and applied to new regions without the need for additional software development: models and indicators can freely be selected and parameterised to achieve maximum relevance for addressing the issues in the region under study. When the generic ISDSS does not fulfil all user requirements, the system can be extended with other models, which may be existing, region-specific models or models developed to simulate particular relevant processes. In such cases, software development and adaptations of the user interface are required for the incorporation of these models, resulting in a tailor-made ISDSS. Such a system includes models from a wider range of disciplines and can as such (additionally) incorporate components for virtually any process that can be modelled. Current applications include integrations of climate, hydrology, water quality, vegetation dynamics, biodiversity and ecosystem services models. All these models are dynamic simulation models with temporal resolutions varying between minutes and years and a time horizon of 20 to 50 years into the future. While some socio-economic models incorporated are non-spatial, most others are spatially explicit. Most tailor-made systems include different spatial hierarchies and resolutions within one integrated model. In this contribution we will focus on the development history of the generic ISDSS and demonstrate its applicability to a diverse range of regions worldwide. Furthermore we will show how parallel development trajectories of tailor-made systems and a generic tool can co-exist and how developments in one system can be reused in other systems. We will demonstrate how the development of all these systems has been made possible by building upon experience and reusing models, software and design, leading to the evolution of a (more) generically applicable framework. We will discuss the prerequisites to achieving this high level of reusability on various levels: model integration, ISDSS development and user interface design. From the above applications we have learned the following lessons: (1) ISDSS development is a joint effort of users, scientists and IT-specialists, (2) In ISDSS development, software development is facilitating, not leading, (3) Conceptual challenges regarding model integration cannot be solved by technical solutions alone, (4) The need for software development in various phases of the development and use of an ISDSS can and should be minimized, (5) Reusable concepts and components allow for efficient development of new ISDSS, although genericity remains a trade-off, (6) Funding mechanisms should be accounted for in planning longterm ISDSS development and implementation trajectories.