In the cities of the southwestern United States, regional warming combined with increasing urban populations and the resulting urban heat effect are straining limited supplies of electricity and water. Cities can be designed that are more resilient, minimizing human impacts and energy and water stresses, under scenarios of decadal warming trends. However, improved micro-scale climate models that resolve urban landscape hydrology, vegetation dynamics and patch-scale water and energy balances are needed to support the design of these resilient urban systems; funds are provided to create and validate a modeling system capable of resolving these dynamics. The tRIBS land surface hydrology model will be modified for urban environments and coupled with the vertically nested WRF 3.2 mesoscale and microclimate model. The combined model will be used to test the efficacy of different urban green-space and neighborhood designs under climate change scenarios with respect to the water and energy balance, demand for and optimal application of irrigation water, patch-scale air temperatures and humidities, and urban flooding responses. This newly coupled model will transform the design of urban neighborhoods to be quantifiably more adaptive and resilient to all types of decadal climate change.

This study will demonstrate the technical feasibility, empirical validity, and computational tractability of this approach using neighborhoods in Phoenix, AZ as case studies. The microclimate predictions of the model will be useful to predict neighborhood-level human health and social impacts, water and energy use, urban heat island effects, and urban flooding, in neighborhoods in cities around the world. The potential social benefits of this research include a research tool that can empirically validate, quantitative design of urban neighborhoods that are more resilient to climate change and other future challenges (i.e. water or energy shortages), allows the optimization of neighborhoods that minimize water and energy use, mitigate heat island impacts, and improve social and health outcomes. This modeling tool can change cities by making them adaptive by design.