Modeling the impact of land use and climate change on neighborhood-scale evaporation and nighttime cooling: A surface energy balance approach

We investigated the impacts of temperature changes derived from climate change scenarios and land cover change on patterns of external residential water consumption and nighttime cooling in suburban Hillsboro, Oregon. Three downscaled climate warming scenarios and two land cover change scenarios (sprawl and dense) for the 2040s were used as inputs for an urban energy balance model, the Local-Scale Urban Meteorological Parameterization Scheme (LUMPS). Based on the surface energy fluxes simulated by the LUMPS model, we calculate that the combination of the sprawl scenario with the 3 °C temperature rise increases external water consumption by 4061 L per household for August. Alternately, dense development concomitant with temperature increase constrains increases in water consumption, but reduces nighttime cooling rates by more than 0.3 °C. Increasing the fraction of trees would increase efficiency in promoting urban cooling while reducing external water consumption. This study demonstrates that urban land cover and water use are naturally intertwined at the neighborhood scale, suggesting that urban land-use planning and water management should be fully integrated to design cities that can accommodate future population growth and development while minimizing negative impacts of potential climate change.

► Land cover and water use are naturally intertwined at the neighborhood scale due to their prominence in affecting the local surface energy balance.
► Urban land-use planning and water management must also be fully integrated to design sustainable cities that can accommodate future climate change and population growth.
► Future development plans need to be spatially explicit and integrate current vegetation and water consumption patterns.
► Heavily developed neighborhoods should not experience increased future imperviousness in a warming climate.
► Density should be increased in sprawling, highly vegetated neighborhoods, to reduce external water consumption.