UCLA

This thesis explores projected mid-21st century changes to surface hydrological fluxes and states in the Los Angeles region at 2km resolution. This work quantifies and describes potential impacts of climate change to precipitation, runoff, evapotranspiration and soil column moisture content in the Los Angeles region. Little previous research has focused on the impacts of climate change to water resources and surface hydrology in this region. We simulate detailed climatologies of surface hydrology for the late 20th century and mid 21st century. By looking at differences between the future and baseline periods, mid-century changes to surface hydrology relative to the late 20th century can be evaluated in our study region.

Using dynamical downscaling techniques and the Weather Research and Forecasting (WRF) model, we develop a detailed high-resolution climatology for the Los Angeles region from coarse-resolution North America Regional Reanalysis (NARR) data and output from five "business as usual" global climate model (GCMs) simulations in the Fifth Coupled Model Intercomparison Project (CMIP5) data archive. Output from the dynamical downscaling WRF simulations is then used to force the offline Noah Land Surface Model (Noah&ndashLSM), which simulates near-surface state variables and surface turbulent fluxes. This methodology allows us to assess potential impacts of climate change to surface hydrology in the Los Angeles region at scales relevant to local policy makers or water resources planners.