Michael E. Wieczorek Andrew E. LaMotte 2010 tabular digital data Digital Data Series DS-491-07 Reston, Virginia U.S. Geological Survey http://water.usgs.gov/lookup/getspatial?mrb_e2rf1_contact This tabular data set represents the average contact time, in units of days, compiled for every MRB_E2RF1 catchment of Major River Basins (MRBs, Crawford and others, 2006). Contact time, as described in Vitvar and others (2002), is defined as the baseflow residence time in the subsurface. The source data set was the U.S. Geological Survey's (USGS) 1-kilometer grid for the conterminous United States (D.M. Wolock, U.S. Geological Survey, written commun., 2008). The MRB_E2RF1 catchments are based on a modified version of the U.S. Environmental Protection Agency's (USEPA) RF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002; Brakebill and others, 2011). Data were compiled for every MRB_E2RF1 catchment for the conterminous United States covering New England and Mid-Atlantic (MRB1), South Atlantic-Gulf and Tennessee (MRB2), the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy (MRB3), the Missouri (MRB4), the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf (MRB5), the Rio Grande, Colorado, and the Great basin (MRB6), the Pacific Northwest (MRB7) river basins, and California (MRB8). This tabular data set was created and used by the U.S. Geological Survey (USGS) specifically to estimate contact time for the 2002 time period per watershed segment in the application of the national SPAtially Referenced Regression On Watershed attributes (SPARROW) model . The SPARROW model relates in-stream water-quality measurements to spatially referenced characteristics of watersheds, including contaminant sources and factors influencing terrestrial and stream transport. The model empirically estimates the origin and fate of contaminants in streams, and quantifies uncertainties in these estimates based on model coefficient error and unexplained variability in the observed data. For more information on the USGS SPARROW model please refer to: http://water.usgs.gov/nawqa/sparrow/intro/intro.html. 2002 publication date Complete None planned -127.910792 -65.327751 51.657387 23.243486 None Contact time Inlandwaters MRB_E2RF1 MRB_E2RF1WS Catchment NAWQA SPARROW None Conterminous United States MRB Major River Basins MRB2 SAGT South Atlantic-Gulf and Tennessee MRB3 GLMR Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy MRB4 MORI Missouri MRB5 LMTG Lower Mississippi, Arkansas-White-Red, and Texas-Gulf MRB7 PANW Pacific Northwest PANW Pacific Northwest MRB8 CALI California None None Michael E. Wieczorek U.S. Geological Survey mailing address

5522 Research Park Drive

Baltimore MD 21228 USA 443-498-5550 443-498-5510 mewieczo@usgs.gov http://water.usgs.gov/GIS/browse/mrb_e2rf1_contact.jpg Illlustration of data set JPG Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 3; ESRI ArcCatalog 9.3.1.3000 Charles G. Crawford Pixie A. Hamilton Anne B. Hoos October 5, 2006 Reston, Virginia U.S. Geological Survey Prepared by Charlie Crawford, Pixie Hamilton, and Anne Hoos for a NAWQA National Liaison Meeting, Washington D.C., October 5, 2006. http://water.usgs.gov/nawqa/studies/mrb/mrb_factsheet.pdf Vitvar, Tomas Burns, Douglass A. Lawrence, Gregory B. McDonnell, Jeffrey J. Wolock, David M. 2002 Published online in Wiley InterScience (www.interscience.wiley.com). DOI: 10.1002/hyp.5027 The values of the items were verified for computational accuracy by the author and reviewers. Complete. Jacqueline V. Nolan John W. Brakebill Richard B. Alexander Gregory E. Schwarz Febuary 22, 2002 vector digital data USGS Open-File Report USGS Open-File Report 02-40 Reston, Virginia U.S. Geological Survey http://water.usgs.gov/lookup/getspatial?erf1_2 online 2008 publication date ERF1_2 The source provided a reach network to construct reach catchments for selected MRBs. John W. Brakebill Silvia E. Terziotti 20110222 vector digital data General Information Web Only Baltimore, MD U.S. Geological Survey http://water.usgs.gov/lookup/getspatial?mrb_e2rf1 online 2011 publication date MRB_E2RF1 The source data provided a reach network to construct reach catchments for MRBs and subsequent processing. John W. Brakebill Silvia E. Terziotti 20110222 raster digital data General Information Web Only Baltimore, MD U.S. Geological Survey http://water.usgs.gov/lookup/getspatial?mrb_e2rf1ws online 2011 publication date MRB_E2RF1WS The source data provided reach catchments for MRBs and subsequent processing. 1) Received the contact time GRID from USGS ( D.M. Wolock, U.S. Geological Survey, written commun., 2008) 2) Resampled the contact time GRID from 1-kilometer to 100-meter to match the resolution of the MRB_E2RF1 catchment GRIDs. 3) Summarized contact time by catchment using the ZONALMEAN command in GRID. 4) Exported results into a dbf file format. 2008 Metadata imported. T:\MRB\meta\RF1\xml\contact_rf1.xml 20100824 15020200 contact_rf1 dbf tabular data files ESRI COV_PERC Percent of catchment that source GRID covers U.S. Geological Survey 0.0 100.0 Percentage OID Internal feature number ESRI Sequential unique whole numbers that are automatically generated CNTC_MEAN Average contact time for catchment in days U.S. Geological Survey 0.0 90171.29 days CNTC_AREA Area of catchment that source GRID covers U.S. Geological Survey 100 2066510700 Square meters RF1ID Unique ID to relate to the item MRB_ID in the MRB_E2RF1WS catchment and MRB_E2RF1 reach coverages. U.S. Geological Survey Sequential unique whole numbers that are automatically generated BASIN_AREA Area of catchment U.S. Geological Survey 100 2066510700 Square meters NODATA_ARE Area of catchment that source GRID does not cover U.S. Geological Survey 0 2066510700 Square meters U.S. Geological Survey Ask USGS -- Water Webserver Team mailing address

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Reston Virginia 20192 USA 1-888-275-8747 (1-888-ASK-USGS) http://water.usgs.gov/user_feedback_form.html Downloadable Data Although this dataset has been used by the U.S. Geological Survey, U.S. Department of the Interior, no warranty expressed or implied is made by the U.S. Geological Survey as to the accuracy of the data and related materials. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the U.S. Geological Survey in the use of these data, software, or related materials. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. dbf Full coverage zipped 83 KB http://water.usgs.gov/GIS/dsdl/mrb_e2rf1_contact_mrb1.zip dbf Full coverage zipped 133 KB http://water.usgs.gov/GIS/dsdl/mrb_e2rf1_contact_mrb2.zip dbf Full coverage zipped 176 KB http://water.usgs.gov/GIS/dsdl/mrb_e2rf1_contact_mrb3.zip dbf Full coverage zipped 183 KB http://water.usgs.gov/GIS/dsdl/mrb_e2rf1_contact_mrb4.zip dbf Full coverage zipped 138 KB http://water.usgs.gov/GIS/dsdl/mrb_e2rf1_contact_mrb5.zip dbf Full coverage zipped 89 KB http://water.usgs.gov/GIS/dsdl/mrb_e2rf1_contact_mrb6.zip dbf Full coverage zipped 167 KB http://water.usgs.gov/GIS/dsdl/mrb_e2rf1_contact_mrb7.zip dbf Full coverage zipped 42 KB http://water.usgs.gov/GIS/dsdl/mrb_e2rf1_contact_mrb8.zip None. This dataset is provided by the USGS as a public service. 20100817 U.S. Geological Survey Ask USGS -- Water Webserver Team mailing address

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Reston Virginia 20192 USA 1-888-275-8747 (1-888-ASK-USGS) http://answers.usgs.gov/cgi-bin/gsanswers?pemail=h2oteam&subject=GIS+Dataset+mrb_e2rf1_contact FGDC Content Standards for Digital Geospatial Metadata FGDC-STD-001-1998