Prediction of Effects of Changing Precipitation Extremes on Urban Water QualityEPA Grant Number: R835195
Title: Prediction of Effects of Changing Precipitation Extremes on Urban Water Quality
Investigators: Lettenmaier, Dennis P. , Yearsley, John
Current Investigators: Lettenmaier, Dennis P. , Nijssen, Bart , Yearsley, John , Baptiste, Marisa , Sun, Ning
Institution: University of Washington
EPA Project Officer: Packard, Benjamin H
Project Period: June 1, 2012 through May 31, 2016
Project Amount: $699,905
RFA: Extreme Event Impacts on Air Quality and Water Quality with a Changing Global Climate (2011) RFA Text | Recipients Lists
Research Category: Air Quality and Air Toxics , Global Climate Change , Water and Watersheds , Climate Change , Air , Water
Changes in streamflow at the global and continental scale over recent decades are now well documented. These changes are most apparent in the western U.S., however they have been documented elsewhere in the U.S. as well. On the other hand, the effects of climate change on water quality, and urban water quality in particular have received much less attention.
The work we propose will develop tools and assessment products for evaluation of potential changes in water quality in urban regions that will accompany IPCC projections of climate change over the continental U.S. In doing so, we will draw on 25 years of progress at the University of Washington by the PI and his colleagues in the development of hydrologic modeling methods and downscaling procedures for the assessment of hydrologic impacts of climate change. This work dates to the EPA Reports to Congress ofthe 1980s, and since then has included studies of hydrologic impacts of climate change over a number of large U.S. and global river basins.
The overarching science question we will address is How has and will the physical-chemical quality of urban streams change in a warming climate? The approach we propose will utilize dynamically downscaled IPCC AR4 climate scenarios archived by the North American Climate Change Assessment Project (NARCCAP), as well as other Regional Climate Model (RCM) scenarios utilized by the PI and colleagues in recent work. It will use the fully distributed DHSVM hydrology model, which utilizes a high resolution grid-based framework that is particularly suitable for regional applications, linked with water quality modules from the EPA's BASINS modeling system. A "plug-in" capability will be developed for DHSVM that will link it with the GIS-capabilities of BASINS, and particularly water quality parameterizations from the Stormwater Management Model (SWMM). ROll interface files will be used to access SWMM water quality kinetics for sediments, nutrients (C and N), fecal coliform bacteria, and selected toxic substances, the combined suite of which will be considered as indicators of urban water quality. We will also model stream temperature, using the co-PI's RBM10 stream quality model, developed when he was at EPA. We will demonstrate the approach for two or three selected case studies, candidates for which will include the Puget Sound drainage basin, part of the Great Lakes Basin, the Los Angeles Bight, and Chesapeake Bay.
The proposed research directly addresses all four of the questions outlined in the RFA. It will make unique linkages of the PI and co-PI's expertise in hydrologic and water quality assessments of climate change to EPA's suite of water quality models, with application to urban areas identified as of key interest to EPA in its 2011-2015 Strategic Plan.