An integrated urban development and ecological simulation model

This paper develops an integrated strategy to model the urban development and ecological dynamics in the Central Puget Sound Region. This effort is part of the Puget Sound Regional Integrated Synthesis model (PRISM) – an interdisciplinary initiative at the University of Washington aiming to develop a dynamic and integrated understanding of the environmental and human systems in the Puget Sound. We describe a model that predicts the environmental stresses associated with urban development and related changes in land use and human activities under alternative demographic, economic, environmental, and policy scenarios. We build on UrbanSim, an existing urban simulation model developed by Waddell [42]. The principal urban actors, represented in the model as objects corresponding to businesses, households, developers, and governments, make choices about location of activities and land development. We extend the object properties and methods now implemented in the UrbanSim model to predict three types of human-induced environmental stressors: land conversion, resource use, and emissions. The core location model in UrbanSim will be revised from its current aggregate structure to one based on microsimulation, and from a zone description of space to one based on a high-resolution grid structure. We will use a spatially explicit process-based landscape modeling approach to replicate ecosystem processes and represent land use–cover interactions at the regional scale. The output of the urban ecological model will serve as the input to several biophysical models for hydrology, hillslope stability, water quality, atmosphere, and ecosystems. Ecological changes will feed back on the choices of both households and business locations, and availability of land and resources.