Multi-resolution integrated assessment and modelling of climate change impacts on water resources in arid and semiarid regions

Approximately one-third of the Earth’s land surface is considered to be arid or semiarid. The availability of water in such regions is particularly sensitive to climate variability while the demand for water is experiencing an explosive increase as populations continue to grow. The competition for available freshwater is exerting considerable pressure on the management of available water resources. If basin-scale water sustainability is to be achieved, managers must somehow attain a balance between supply and demand among the various users throughout the basin, not just for the basin as a whole. The complexity of the interactions between the natural hydrological system and the human environment leaves modelling as the best mechanism for integrating new knowledge into the decision-making process. To this end, the NSF Center for Sustainability of semi-Arid Hydrology and Riparian Areas (SAHRA) is in the process of developing a multi-resolution integrated modelling framework for the Rio Grande basin in the southwest USA. This paper presents a blueprint of the modelling framework in the context of integrated assessment, describes achievements so far and discusses the science questions which the framework will address.