Future projections of global population distribution and urbanization become increasingly important in scenario-based assessments of climate related exposure and vulnerability. The 2UP model is developed to simulate urban growth and population distribution on global scale in a spatially explicit way. This background report is written with the intention to qualitatively describe the 2UP model, and is aimed at giving insight into the design of the model and how it is implemented.
Towards an Urban Preview (2UP)
The 2UP model enables the spatially explicit simulation of future population distribution and urban growth on a global scale. As the global population is projected to become increasingly urban, which triggers the worldwide expansion of urban areas, the model specifically accounts for the change in urban population and urban expansion. Additionally, the model is also used to disaggregate national-level GDP scenarios. Both the population and GDP scenarios are provided by the Shared Socioeconomic Pathways.
The resulting spatially explicit projections of population growth, urban expansion and economic development have a high resolution of 30 arcseconds. To the best of our knowledge, it provides the most detailed global urban growth scenarios that are currently available. The maps illustrate the spectrum of possible (urban) population growth scenarios up to 2050. Overall, they can be applied for the assessment of global flood risks, and they are potentially very useful to facilitate ongoing global change research.
Global flood risk
The 2UP output will be applied as exposure data in the Aqueduct Flood Risk Analyzer (http://floods.wri.org) for the assessment of global flood risks. The World Resources Institute (WRI), with aid of Deltares, VU University Amsterdam, Utrecht University, and PBL, is working on the development of this online instrument that can measure flood risks at a global level. It is designed for the detailed assessment of global flood risk and will allow users to prioritize where in the world attention to flood risk and flood risk adaptation is needed. It also provides country estimates of the costs and benefits of disaster risk reduction strategies.