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NASA-Modified Precipitation Products to Improve EPA Nonpoint Source Water Quality Modeling for the Chesapeake BayThe Environmental Protection Agency (EPA) has estimated that over 20,000 water bodies within the United States do not meet water quality standards. Ninety percent of the impairments are typically caused by nonpoint sources. One of the regulations in the Clean Water Act of 1972 requires States to monitor the Total Maximum Daily Load (TMDL), or the amount of pollution that can be carried by a water body before it is determined to be "polluted", for any watershed in the U.S.. In response to this mandate, the EPA developed Better Assessment Science Integrating Nonpoint Sources (BASINS) as a Decision Support Tool (DST) for assessing pollution and to guide the decision making process for improving water quality. One of the models in BASINS, the Hydrological Simulation Program -- Fortran (HSPF), computes daily stream flow rates and pollutant concentration at each basin outlet. By design, precipitation and other meteorological data from weather stations serve as standard model input. In practice, these stations may be unable to capture the spatial heterogeneity of precipitation events especially if they are few and far between. An attempt was made to resolve this issue by substituting station data with NASA modified/NOAA precipitation data. Using these data within HSPF, stream flow was calculated for seven watersheds in the Chesapeake Bay Basin during low flow periods, convective storm periods, and annual flows. In almost every case, the modeling performance of HSPF increased when using the NASA-modified precipitation data, resulting in better stream flow statistics and, ultimately, in improved water quality assessment.
Document ID
Document Type
Preprint (Draft being sent to journal)
Nigro, Joseph (NASA Goddard Space Flight Center Greenbelt, MD, United States)
Toll, David (NASA Goddard Space Flight Center Greenbelt, MD, United States)
Partington, Ed (Environmental Protection Agency Washington, DC, United States)
Ni-Meister, Wenge (Hunter Coll. New York, NY, United States)
Lee, Shihyan (Hunter Coll. New York, NY, United States)
Gutierrez-Magness, Angelica (Geological Survey Baltimore, MD, United States)
Engman, Ted (NASA Goddard Space Flight Center Greenbelt, MD, United States)
Arsenault, Kristi (Center for Research on Environment and Water Calverton, MD, United States)
Date Acquired
August 25, 2013
Publication Date
January 1, 2010
Subject Category
Environment Pollution
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