Effects of landscape modification on evapotranspiration, microclimate, energy use, and water use in urban environments

Landscape changes caused by urbanization influence urban water cycle components including evapotranspiration (ET), runoff and water use. The cascading effects of altered landscape and modified water cycle fluxes and stores on microclimate and energy usage are uncertain, yet critical for urban planning and design, water management and policy making, and green infrastructure design. In the semiarid urban west, landscape changes in residential areas meant to reduce water use may not achieve the expected result. ET rates may be modified, altering the microclimate and air temperature, which may cascade to increased energy use for cooling in the summertime and feedback to increased water use at power generation facilities. This dissertation presents the development of a modeling framework to study these complex interconnections of the water cycle, urban form and landscape characteristics, microclimate, and energy and water use. To enable metropolitan scale analyses, the use of Synthetic Aperture Radar (SAR) and other satellite data to estimate urban form and vegetation characteristics across metropolitan areas is introduced in the third chapter. A modification to the Local-scale Urban Meteorological Parameterization Scheme (LUMPS) is introduced and evaluated in the fourth chapter. LUMPS can simulate sensible and latent heat fluxes spatially and temporally. The advancement presented in this dissertation are new relationships for two key LUMPS parameters to roughness length, surface resistance, and soil moisture. The final part of the dissertation introduces a new coupled water cycle, energy budget, microclimate, energy use, and water use modeling framework to study the complexities of the urban system interconnections. The modeling system is applied to quantify the effects of residential landscape conversion from traditional irrigated turf grass to low water use vegetation on heat fluxes, microclimate, energy use, and water use. The results indicate the use of low water use vegetation increases sensible heat flux and decreases latent flux, which is accompanied by an increase in air temperature and a 1.5% increase in energy usage, although the outdoor water use is reduced.