Scenario Discovery in land use change models

Abstract

There are bidirectional interactions between land-use and environmental systems: the way land is used has impacts on the environment, while changes in the environment have impacts on the way land is used. The use of Land Use Change models enables policy makers to gain insights into possible developments of the land-use system, the possible causes of these developments, and their consequences. Due to assumptions, simplifications, or lack of data many uncertainties remain concerning these forces and how they could play out in the future. Currently, a deductive scenario approach is the main method used to deal with these uncertainties. Using this approach, normally two to six scenarios are developed, for which values of the uncertain driving forces vary in accordance with the different scenarios. However, such a deductive approach only characterizes a small part of the uncertainty space, and therefore increases the chance of overlooking certain regions of the uncertainty space, corresponding with the real future, which were not characterized by any of the scenarios considered. This research aims to explore the use of Scenario Discovery with the aid of land use change models. To answer this research question, the Land Use Scanner model is used. This model was used in earlier research in the simulation of future land use patterns using the so-called Delta Scenarios. These Delta Scenarios and their corresponding future land use patterns simulated with the Land Use Scanner model are used to compare to the results of this research. This research resulted in six scenarios which differ from the Delta Scenarios in the narrative and the corresponding land-use patterns. However, the Scenario Discovery scenarios differ in other ways as well. Firstly, the development of the Scenario Discovery scenarios makes the analyst aware of under which conditions a combination of similar driving forces lead to different land-use patterns. Also, this approach makes the analyst aware under which conditions combinations of different driving forces still yield similar land-use patterns. Next to this, the Scenario Discovery scenarios show which driving forces are most important. Overall, this means that the scenarios identified with Scenario Discovery differ from the Delta Scenarios in the way that they provide analysts and policymakers with several insights, which can support sufficient informed decision making, which are overlooked when with the development and use of the Delta Scenarios. As this research demonstrated the potential of Scenario Discovery in the land-use change modelling field, it is recommended for land-use change model users, such as LUS model users, to use Scenario Discovery for the development of scenarios. As for the decision-makers in spatial planning, it is recommended to involve land-use change models more into the decision-making process. Lastly, on a more general note, the use of story and simulation approaches in model-based decision making should be reconsidered, and instead, it is recommended to research the possibilities of Scenario Discovery in various modelling fields.