Consequences of Global Climate and Emissions Changes on U.S. Water Quality: An Integrated Modeling Assessment

EPA Grant Number: R834189
Title: Consequences of Global Climate and Emissions Changes on U.S. Water Quality: An Integrated Modeling Assessment
Investigators: Liang, Xin-Zhong , Arnold, Jeff , Srinivasan, Raghavan , Tuppad, Pushpa , Wuebbles, Donald J.
Institution: University of Maryland
EPA Project Officer: Hiscock, Michael
Project Period: August 1, 2009 through July 31, 2012 (Extended to July 31, 2014)
Project Amount: $723,559
RFA: Consequences of Global Change for Water Quality (2008) RFA Text |  Recipients Lists
Research Category: Ecological Indicators/Assessment/Restoration , Global Climate Change , Water and Watersheds , Ecosystems , Climate Change , Water


The objective of this study is to quantify and understand the impacts of global climate and emission changes from the present to 2050 on U.S. water quality, focusing on the nitrogen cycle. It will derive from the application of a unique, state-of-the-art, integrated modeling system that couples a global climate-chemical transport component with a mesoscale regional climate-hydrology-air quality-water quality component over North America. The system predicts the interactive dynamical, physical and biogeochemical processes that govern the movement of water and pollutants in the air and on land (surface, subsurface, streams, plants, human). It incorporates multiple alternative model configurations representing the likely range of climate sensitivity and biogeochemistry response under the conceivable anthropogenic emissions scenarios to rigorously assess the result uncertainty for improving risk analysis.


We propose to elaborate the consequences on U.S. water quality from regional atmospheric deposition, agricultural practice, and potential adaptation in response to global change. Historical simulations of the observed climate, crop production, and water quality will first be conducted for system validation and also used as the baseline reference for future changes. Projections for 2050 will then be made to quantify the individual and combined impacts of global climate and emissions changes on U.S. water quality, accounting for land conversion to alternative food and biofuel crops. Subsequent sensitivity experiments will determine the dominant pollutant sources and the key result uncertainties. Diagnostic studies will further improve process understanding of the response of water quantity and quality at sensitive endpoints (lakes, rivers, streams, estuaries, wetlands, coastal oceans) to future climatic shifts in weather regimes, storm activities, and hydrologic extremes. Collectively, we will identify, at the national scale, relative vulnerabilities of U.S. water resources to global change, and thus provide scientific guidance for developing adaptive strategies prioritized among regions to effectively manage future outcomes.

Expected Results:

Through this integrated modeling assessment, we will make a major contribution to a key goal of the EPA Global Change Research Program to study consequences of global change for U.S. water quality to support human and aquatic life uses. The advanced state of the modeling system will result in a more complete understanding of complex interactions among regional climate, terrestrial hydrology, agricultural practice, human management, air pollution, and water quality across a full range of spatial and temporal scales.

Publications and Presentations:

Publications have been submitted on this project: View all 8 publications for this project

Journal Articles:

Journal Articles have been submitted on this project: View all 6 journal articles for this project

Supplemental Keywords:

nutrient, pathogen, bacteria, sediment, water yield, water supply, streamflow, surface runoff, soil moisture, groundwater recharge, discharge, fertilizer, pesticide, irrigation, drainage, tillage, dam control, urbanization, livestock, GCM, RCM, AQM, WQM,, RFA, Air, climate change, Air Pollution Effects, Atmosphere

Progress and Final Reports:

  • 2010 Progress Report
  • 2011 Progress Report
  • 2012 Progress Report
  • 2013 Progress Report
  • Final Report