Groundwater Inventory and Mapping Project, a cooperative effort between the Water Bureau - Michigan Department of Environmental Quality, USGS - Michigan Water Science Center and Michigan State University - Institute of Water Research, RS&GIS and Biosystems and Agricultural Engineering. This project was mandated by P.A. 148 (Michigan Acts of 2003). Major funding was provided by MDEQ, supplemented with additional funds from the USGS Cooperative Water Program. 1.0 vector digital data http://gwmap.rsgis.msu.edu/ Groundwater Inventory and Map Project 1st PDF Document http://gwmap.rsgis.msu.edu/ This data set provides estimates of the ground-water contribution to stream flow, frequently referred to as base flow, in cubic feet per second. The baseflow of a stream or river is the amount of groundwater discharged from an aquifer to the watercourse. This discharge occurs year-round, and fluctuates seasonally depending on the level of the water in the aquifer. Baseflow is supplemented by direct runoff during and immediately after precipitation or melt events, resulting in peaks on a hydrograph showing stream flow through time. The process of dividing these peaks into base flow and runoff is called hydrograph separation. Hydrograph separations were completed for all USGS stream- flow gaging stations in Michigan that had more than 10 years of daily records. Sites that were clearly affected by upstream impoundments (lakes, dams) were excluded. No attempt was made to detect or correct for trends in the data. This may lead to some errors in the comparison of streams with data from different time periods if there is an underlying temporal trend in the data, but inclusion of all records in the analysis was necessary to increase the data pool and provide better spatial coverage. Watersheds were delineated for each of the 208 stream-flow gaging stations, and various characteristics of each watershed, such as topographic relief, surficial geology, land cover, growing degree days, annual and winter-season precipitation, and others were tabulated. Regression modeling, described in the Technical Report, was used to estimate the baseflow for each steam segment of the 1:100,000-scale National Hydrography Dataset. This data was generated to support decision making pursuant to Michigan PA 148. Several areas in Southeast Michigan, particualrly within the Rouge, Huron, and Raisin watersheds, were not estimated. Other areas, such as islands within the Great lakes, were also not estimated. Complete Unknown -90.172753 -81.801049 47.53332 41.670939 None Stream flow Ground water Base flow None Michigan None No restrictions on access No restrictions on use US Geological Survey Steve Aichele Geographer mailing

6520 Mercantile Way, Suite 5

Lansing Michigan 48911 US 517-887-8918 517-887-8937 saichele@usgs.gov U.S. Geological Survey Michigan Water Science Center Unclassified Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 3; ESRI ArcGIS 10.0.5.4400 The estimated baseflow values are consistent with general trends across the state but do not explicitly account for withdrawals or augmentations. Although flows generally decrease downstream, no explicit mass conservation was required in the model, thus the flow in a reach may not equal the sum of its contributing reaches. None None Positional accuracy is identical to source linework from National Hydrography Dataset NA USGS None NHD 100K Applied regression equation from process step 1 to attributes developed in process step 2 to arrive at estiomated base flow for each reach inthe 1:100K NHD. Developed a multivariate regression model relating base flow (as described by HYSEP 3, Sloto and Crouse, 1998) to characteristics of watersheds based on Neff and others (2005). Significant predictive variables were: Eastern Lower Peninsula - Area, agricultural fraction, urban fraction, annual growing degree days, annual precipitation, and percent lacustrine deposits. Western Lower Peninsula - Area, winter perecipitation, till percentage, and forest percentage Upper peninsula - Area, winter precipitation, growing degree days Sloto, R.A., and Crouse, M.Y., 1998, HYSEP : a computer program for streamflow hydrograph separation and analysis, USGS WRIR 96-4040 Neff, B.P., Day, S.M., Piggott, A.R., and Fuller, L.M., Base Flow in the Great Lakes Basin: U.S. Geological Survey Scientific Investigations Report 2005-5217, 23 p. unknown Calculated relevant landscape characteristics for the watershed associated with each reach in the 1:100K NHD. unknown Delineated drainage basins for stream gages based on conditioned DEM from UGS Aquatic GAP project. unknown Vector String 35019 Grid Cell 1344 1655 1 WGS 1984 Web Mercator 0.0 0.0 0.0 0.0 coordinate pair 0.0001 0.0001 meter D WGS 1984 Major Auxiliary Sphere WGS 1984 Major Auxiliary Sphere 6378137.0 0.0 michigan.WEBMERC.HYD_LN_DEQ_STREAM_BASEFLOW OBJECTID Internal feature number. ESRI Sequential unique whole numbers that are automatically generated. Shape Feature geometry. ESRI Coordinates defining the features. GAP_CODE ORDER_ PU BASE_FLOW YIELD Shape.STLength() Remote Sensing & GIS Research and Outreach Services Justin M Booth Information Technology Professional mailing

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East Lansing MI 48823 United States of America boothj@msu.edu The State of Michigan or the Ground Water Inventory and Mapping Project partnership assumes no liability for results or conclusions drawn from use of this data. 20121024 Remote Sensing & GIS Research and Outreach Services Justin M Booth Information Technology Professional mailing

Geography Building, Michiagn State University

East Lansing MI 48824 United States of America 517-432-0446 517-353-1821 boothj@msu.edu FGDC Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998 local time