Faunt, Claudia C. 2012 vector digital data Reston, Virginia U.S. Geological Survey http://water.usgs.gov/lookup/getspatial?pp1766_DIS Faunt, Claudia C. (editor) 2009 Professional Paper 1766 Reston, Virginia U.S. Geological Survey 3 chapters, 1 appendix http://pubs.usgs.gov/pp/1766/PP_1766.pdf This digital dataset defines the model grid and altitudes of the top of the 10 model layers and base of the model simulated in the transient hydrologic model of the Central Valley flow system. The Central Valley encompasses an approximate 50,000 square-kilometer region of California. The complex hydrologic system of the Central Valley is simulated using the USGS numerical modeling code MODFLOW-FMP (Schmid and others, 2006), which estimates dynamically integrated supply-and-demand components of irrigated agriculture as part of the simulation of surface-water and ground-water flow based on MODFLOW-2000. This application is referred to here as the Central Valley Hydrologic Model (CVHM) (Faunt, 2009). Utilizing MODFLOW-FMP, the CVHM simulates groundwater and surface-water flow, irrigated agriculture, land subsidence, and other key processes in the Central Valley on a monthly basis from 1961-2003. The total active modeled area is an approximately 20,334 square-miles on a finite difference grid comprising 441 rows, 98 columns. Slightly less that 50 percent of the cells are active. It has a uniform horizontal discretization of 1x1 square mile and is oriented parallel to the valley axis, 34 degrees west of north (Faunt, 2009).The thickness of model layers is derived by sequentially subtracting the altitudes of the uppermost to the lowermost model layers. Most model layers range in thickness from 15 to more than 300 meters, and thickness generally increases with depth (Faunt, 2009). The upper 3 model layers are used to simulate the relatively shallow flow through basin-fill sediments. Layers 4 and 5 are used to represent the Corcoran Clay Member of the Tulare Formation. The lower 5 layers are used to simulate the confined deeper portion of the basin-fill sediments. The CVHM is the most recent regional-scale model of the Central Valley developed by the U.S. Geological Survey (USGS).The CVHM was developed as part of the USGS Groundwater Resources Program (see "Foreword", Chapter A, page iii, for details). The model grid was used as input to MODFLOW-FMP, the USGS 3-dimensional finite-difference code used to simulate flow in the CVHM. The one square mile cells were used to define the resolution and extent of the CVHM. The CVHM is a tool that accounts for integrated, variable water supply and demand, and simulates surface-water and groundwater-flow across the entire Central Valley system. The CVHM model-layer dataset is one of many layers in a geospatial database supporting the USGS Central Valley Groundwater Availability Project. Regional groundwater availability studies quantify current groundwater resources, evaluate how those resources have changed through time, and provide tools that decision makers can use to predict system responses to future development and climate variability and change. To provide information to stakeholders addressing these issues, the USGS made a detailed assessment of groundwater availability of the Central Valley aquifer system, which includes: (1) the present status of groundwater resources; (2) how these resources have changed over time; and (3) tools to assess system responses to stresses from future human uses and climate variability and change. This effort builds on previous investigations, such as the USGS Central Valley Regional Aquifer System and Analysis (CV-RASA) project and several other groundwater studies in the Valley completed by Federal, State and local agencies at differing scales. Data from these previous studies were the foundation of the Central Valley geospatial database. These and other data were reexamined through a series of regional-scale hydrologic investigations to provide updated and spatially consistent interpretations for the Central Valley Groundwater Availability study. In some cases, new data were collected to augment existing information. Data compiled from the studies include geology (in particular, borehole lithology and the extent and thickness of the Corcoran Clay Member of the Tulare Formation), topography, remote sensing, climate (precipitation and temperature), geophysics, vegetation and land use, vegetation properties, hydrology (stream network and flows), groundwater levels, subsidence, chemistry, and soils. Digital elevation models, geologic maps, borehole information, cross sections, and other 3-dimensional models were used to develop the texture model which represents the properties and geometry of the Central Valley alluvial deposits. The resulting geospatial database supports characterization and conceptualization of the Central Valley hydrologic system between 1961 and 2003, construction of 3-dimensional hydrogeologic framework and hydrologic flow models, and visualization of analysis and model results. 2009 publication date Complete None planned -123.831528 -117.916328 40.748631 34.519871 ISO 19115 Topic Category inlandWaters geoscientificinformation American Geological Institute Glossary of Geology (http://glossary.agiweb.org/dbtw-wpd/glossary/search.aspx) hydrology hydrogeology groundwater model None Central Valley Aquifer Groundwater Availability of the Central Valley Aquifer CV-RASA Central Valley Hydrologic Model Texture Model Flow Model CVHM U.S. Board of Geographic Names (BGN) and Geographic Names Information System (GNIS) California Central Valley Trinity County Shasta County Tehama County Humboldt County Butte County Mendocino County Glenn County Yuba County Lake County Nevada County Colusa County Sutter County Placer County El Dorado County Yolo County Sonoma County Napa County Sacramento County Amador County Solano County Calaveras County Tuolumne County San Joaquin County Contra Costa County Stanislaus County Alameda County Mariposa County Madera County Merced County Fresno County Santa Clara County San Benito County Monterey County Tulare County Kings County Kern County San Luis Obispo County Santa Barbara County Ventura County Sacramento Valley San Joaquin Valley Central Valley, California None. Data have been checked to ensure the accuracy of the data. If any errors are detected, please notify the originating office. The U.S. Geological Survey strongly recommends that careful attention be paid to the metadata file associated with these data. The U.S. Geological Survey shall not be held liable for improper or incorrect use of the data described and (or) contained herein. Acknowledgement of the U.S. Geological Survey would be appreciated in products derived from these data. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this Federal Geographic Data Committee-compliant metadata file is intended to document the dataset in nonproprietary form, as well as in ArcGIS format, this metadata file may include some ArcGIS-specific terminology. Claudia C. Faunt U.S. Geological Survey Hydrologist mailing and physical address

4165 Spruance Road, Suite 200

San Diego Projects Office

4165 Spruance Road, Suite 200

San Diego California 92101 USA (619) 225-6142 (619) 225-6101 ccfaunt@usgs.gov http://water.usgs.gov/GIS/browse/pp1766_DIS.png Illlustration of data set png Spatial datasets supporting the Central Valley Groundwater Availability project were developed primarily by the U.S. Geological Survey's (USGS) Groundwater Resources Program. This program is conducting large-scale multidisciplinary regional studies of groundwater availability. The U.S. Bureau of Reclamation is supporting the updating of the Central Valley datasets and their documentation and release. Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 3; ESRI ArcCatalog 9.3.1.3500 Attributes added by the GIS and the data-set author were checked by inspection using a GIS. In addition, attributes were checked and evaluated as part of the review process associated with the publication of the source report. Lines forming polygons join at endpoints to completely enclose defined areas. Lines not enclosing areas do not intersect. No duplicate line features exist and all nodes are represented by a single coordinate pair which indicates the beginning or end of a line. All vertices that define the shape of the line are represented by a unique coordinate pair. The polygon features in this dataset are computer-generated and represent the model grid and model layers of the Central Valley Hydrologic Model. The dataset is complete and is not anticipated to change. Horizontal positional accuracy of polygon features in the dataset was tested by visually comparing to digital maps in the region by using a GIS system. Faunt, C. C. Hanson, R.T. Belitz, K. Schmid, W. Predmore, S.P. Rewis, D.L. McPherson, K. 2009 document U.S. Geological Survey Professional Paper 2009-1766 Reston, Virginia U.S. Geological Survey http://pubs.usgs.gov/pp/1766/PP_1766.pdf Faunt, C.C. 2009 U.S. Geological Survey Professional Paper 2009-1766 Reston, Virginia U.S. Geological Survey 500000 online 2009 publication date U.S. Geological Survey Professional Paper 1766-2009 model-layer altitude and thickness values Page, R. W. 1986 Professional Paper 1401-C Reston, VA U.S. Geological Survey http://pubs.usgs.gov/pp/1401c/report.pdf online 2009 publication date Page (1986) Corcoran Clay USGS Earth Resources Observation and Science (EROS) Center 2009 raster digital data Reston, VA U.S. Geological Survey http://eros.usgs.gov/#/Guides/dem online 2009 publication date DEM Digital Elevation Model A GIS was used to develop a polygon file representing the flow-model grid layers. The MODFLOW-FMP ASCII arrays were imported into the GIS shapefile for the corresponding model cell. Altitudes of the tops of the 10 model layers and the bottom of the lowest layer, numbered sequentially from the top layer down, were specified for cells within the model-simulation area (Faunt and others, 2009). The upper altitude of the top layer (layer 1) is the altitude of land surface. In general, the layers range in thickness from 50 to 400 feet, increasing by 50 feet with each progressively deeper layer. However, in order to explicitly represent the hydraulically important Corcoran Clay Member of the Tulare Formation (hereafter referred to as the Corcoran Clay), the layer altitudes have been adjusted based on the extent and thickness of this clay. Where the Corcoran Clay is absent, the tops of layers 2 and 3 are 50 and 150 feet below land surface, respectively. The top of layer 4 is 150 feet below the top of layer 3 (300 feet below land surface). Layers 4 and 5 are essentially "dummy" layers with a 1-foot thickness. Hence, the tops of layers 5 and 6 are 301 and 302 feet below land surface. The tops of layers 7, 8, 9, and 10 are 500, 750, 1,050, and 1,400 feet below land surface, respectively. The base of layer 10 is 1,800 feet below land surface. Where the Corcoran Clay exists, the layers were adjusted to explicitly represent the clay, with layers 4 and 5 representing the Corcoran Clay. Because the depth of the Corcoran Clay ranges from less than 50 feet to more than 400 feet, where the Corcoran Clay exists, the tops of layers 2 and 3 were adjusted proportionally to represent the total thickness of deposits above the Corcoran Clay. During this process, the maximum thicknesses of layers 1 and 2 in this area were capped at 50 and 100 feet, respectively. The top of layer 4 is the top of the Corcoran clay and the top of layer 6 is the base of the Corcoran Clay. The top of layer 5 is the midpoint of the Corcoran Clay, halfway between the top of layers 4 and 6. The tops of layers 7, 8, 9, and 10 are 200, 450, 750, and 1,100 feet below the base of the Corcoran Clay, respectively. Likewise, the base of layer 10 is 1,500 feet below the base of the Corcoran Clay. Williamson and others (1989) 04012005 10482600 Faunt, C.C. USGS Hydrologist mailing and physical address

4165 Spruance Road, Suite 200

San Diego CA 92101 USA (619) 225-6142 ccfaunt@usgs.gov Central Valley, comprised of the Sacramento Valley on the north and the San Joaquin Valley on the south, located in the state of California. Vector G-polygon 43218 Albers Conical Equal Area 29.500000 45.500000 -120.000000 23.000000 0.000000 0.000000 coordinate pair 1609.0 1609.0 meters North American Datum of 1983 Geodetic Reference System 80 6378137.000000 298.257222 North American Vertical Datum of 1988 0.000010 feet Explicit elevation coordinate included with horizontal coordinates DIS Discretization Package - Space and time information (Harbaugh and others, 2000). Altitudes of the top of model layers for the Central Valley Hydrologic Model dataset originator FID Internal feature number. ESRI Sequential unique whole numbers that are automatically generated. 0 43217 OBJECTID Internal feature number. ESRI Sequential unique whole numbers that are automatically generated. 1 43218 Shape Feature geometry. ESRI Coordinates defining the features. CELLNUM Hydrologic model grid cell number, beginning in northwest (upper left) and wrapping west to east (left to right) and south (down). dataset Originator 1 43218 Integer ROW Hydrologic model grid row number, starting in the north and increasing to the south dataset Originator 1 441 Integer COLUMN_ Hydrologic model grid column number, starting on westside and increasing to the east. dataset Originator 1 98 Integer cvr2lay1t Altitude of top of model layer 1 dataset Originator 0 8370 Feet 1 cvr2lay2t Altitude of top of model layer 2 dataset Originator -132.595 3404.98 Feet cvr2lay3t Altitude of top of model layer 3 dataset Originator -166.405 3403.98 Feet cvr2lay4t Altitude of top of model layer 4 dataset Originator -703.922 3253.98 Feet cvr2lay5t Altitude of top of model layer 5 dataset Originator -732.991 3252.98 Feet cvr2lay6t Altitude of top of model layer 6 dataset Originator -787.808 3251.98 Feet cvr2lay7t Altitude of top of model layer 7 dataset Originator -985.808 3053.98 Feet cvr2lay8t Altitude of top of model layer 8 dataset Originator -1235.81 2803.98 Feet cvr2lay9t Altitude of top of model layer 9 dataset Originator -1535.81 2503.98 Feet cvr2lay10t Altitude of top of model layer 10 dataset Originator -1885.81 2153.98 Feet cvr2lay10b Altitude of bottom of model layer 10 dataset Originator -2285.81 1753.98 Feet Each model-grid polygon-feature has 17 attributes. Three attributes are automatically generated by the GIS (FID, OBJECTID, and Shape) for internal software purposes. The remaining attributes were assigned by the author (dataset originator) to define the altitude of the top of model layers within the model domain. Model layer altitudes were used for analysis and for developing input files for the CVHM numerical ground-water flow model. none. U.S. Geological Survey Ask USGS -- Water Webserver Team mailing address

445 National Center

Reston VA 20192 USA 1-888-275-8747 (1-888-ASK-USGS) http://water.usgs.gov/user_feedback_form.html Downloadable Data Digital geospatial datasets for the numerical model of the hydrogeologic landscape and groundwater flow in California's Central Valley. Although these data have 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. 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. The use of firm, trade, or brand names in this report is for identification purposes only and does not constitute endorsement by the U.S. Geological Survey. The names mentioned in this document may be trademarks or registered trademarks of their respective trademark owners. SHP ESRI Shapefile unzip 5.605 http://water.usgs.gov/GIS/dsdl/pp1766_DIS.zip None. This dataset is provided by the USGS as a public service. 2011 20120824 U.S. Geological Survey Ask USGS -- Water Webserver Team mailing address

445 National Center

Reston VA 20192 USA 1-888-275-8747 (1-888-ASK-USGS) http://answers.usgs.gov/cgi-bin/gsanswers?pemail=h2oteam&subject=GIS+Datase+pp1766_DIS FGDC Content Standards for Digital Geospatial Metadata FGDC-STD-001-1998