Please read this document first before viewing the contents of this report. Introduction ---------------------------------- This report contains U.S. Geological Survey (USGS) Open-File Report 2007-1031, titled "Geologic and hydrogeologic information for a geodatabase for the Brazos River alluvium aquifer, Bosque County to Fort Bend County, Texas," by Sachin D. Shah and Natalie A. Houston, version 3, updated September 2007. The data herein are in the format of the Groundwater Availability Model (GAM) Source Data Geodatabase developed by the Texas Water Development Board. Some of the features are designed to hold specific data types and formats, whereas others allow general or nonstandard data. Structure built into this geodatabase will guide the development of a conceptual model and provide a standardized, usable record of source data. Geologic and Hydrogeologic Information ---------------------------------- The overall organization is as follows: \1readme.v3.txt this file \spatial data BRA_SCRDATA.mdb - ESRI ArcGIS 9.1 geodatabase of hydrogeologic data compiled for the Brazos River alluvium aquifer. \FGDC Datasets in this directory are non-proprietary alternatives to the geodatabase. The geodatabase point feature class is provided as a shapefile. A shapefile is a digital vector (non-topological) format for storing geometric location and attribute information. The shapefile format is created by ESRI ArcGIS and can be used by ArcGIS and other widely used GIS software. Allassociated files (.prj, .sbn, .sbx, .shp, .shp.xml, .shx) are components of the shapefiles and are necessary for use in GIS software. Additionally, all database tables are provided as tab-delimited ASCII text and .dbf files, and are no different in attribute content than the database tables. \shapefile GeoLocations.shp - Spatial data of the GeoLocations geodatabase feature class GeoMap.shp - Spatial data of the Geology Map geodatabase feature class StudyArea.shp - Spatial data of the defined study area boundary for data consolidation WellLogs.shp - Spatial data of the geophysical well logs geodatabase feature class Wells.shp - Spatial data of the subsurface hydro wells geodatabase feature class \ASCII_text Microsoft Windows encoded GEOL_CrossSections.txt - ASCII text file of cross section data GEOL_Data.txt - ASCII text file of lithology data GEOP_WellLogData.txt - ASCII text file of geophysical well log data SUBHYD_Conductivity.txt - ASCII text file of hydraulic conductivity data SUBHYD_SpecificCapacity.txt - ASCII text file of specific capacity data SUBHYD_Transmissivity.txt - ASCII text file of transmissivity data \metadata All data users and browsers should refer to the metadata for explanation of codes, process steps, and other necessary information regarding the creation and appropriate use of the database. Data from this report should never be shared without the metadata. Metadata is provided in HTML format. GEOL_CrossSections.htm - Metadata for the cross section data table GEOL_Data.htm - Metadata for the lithology data table GeoLocations.htm - Metadata for the GeoLocations geodatabase feature class GeoMap.htm - Metadata for the Geology Map geodatabase feature class GEOP_WellLogdata.htm - Metadata for the geophysical well log table SUBHYD_Conductivity.htm - Metadata for the hydraulic conductivity data table SUBHYD_SpecificCapacity.htm - Metadata for the specific capacity data table SUBHYD_Transmissivity.htm - Metadata for the transmissivity data table WellLogs.htm - Metadata for the geophysical well logs geodatabase feature class Wells.htm - Metadata for the subsurface hydro wells geodatabase feature class \report Text of report in Microsoft Word (.doc) format and Portable Document Format (.pdf) format. Spatial Reference Information ---------------------------------- Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Planar: Map_Projection: Map_Projection_Name: Albers Conical Equal Area Albers_Conical_Equal_Area: Standard_Parallel: 27.500000 Standard_Parallel: 35.000000 Longitude_of_Central_Meridian: -100.000000 Latitude_of_Projection_Origin: 31.250000 False_Easting: 4921250.000000 False_Northing: 19685000.000000 Planar_Coordinate_Information: Planar_Coordinate_Encoding_Method: coordinate pair Coordinate_Representation: Abscissa_Resolution: 0.100000 Ordinate_Resolution: 0.100000 Planar_Distance_Units: survey feet Geodetic_Model: Horizontal_Datum_Name: North American Datum of 1983 Ellipsoid_Name: Geodetic Reference System 80 Semi-major_Axis: 6378137.000000 Denominator_of_Flattening_Ratio: 298.257222 Conversions ---------------------------------- Inch/Pound to SI Multiply By To obtain Length inch (in.) 2.54 centimeter (cm) inch (in.) 25.4 millimeter (mm) foot (ft) 0.3048 meter (m) mile (mi) 1.609 kilometer (km) Volume per unit time gallon per minute (gpm) 0.06309 liter per second (L/s) Hydraulic conductivity foot per day (ft/d) 0.3048 meter per day (m/d) Transmissivity foot squared per day (ft2/d) 0.09290 meter squared per day (m2/d) [computed from specific capacity 1,500(Q/dd) for an unconfined aquifer, where Q = discharge rate (in gpm) and dd = drawdown (in ft) in well after 1 day, based on Driscoll (1986) assumptions] Vertical coordinate information is referenced to North American Vertical Datum of 1988 (NAVD 88). Horizontal coordinate information is referenced to North American Datum of 1983 (NAD 83). Altitude, as used in this report, refers to distance above the vertical datum. Acronyms ---------------------------------- BEG - Bureau of Economic Geology ESRI - Environmental Systems Research Institute GIS - geographic information system TCEQ - Texas Commission on Environmental Quality TWDB - Texas Water Development Board USGS - U.S. Geological Survey Acknowledgments --------------------------------- The authors thank Dr. Joe Yelderman, Baylor University Department of Geology, for providing valuable data on the Brazos River alluvium aquifer for McLennan County. The authors also thank Dr. Clyde Munster, Department of Biological and Agricultural Engineering, Texas A&M University, for site access and Brazos River alluvium aquifer information for Burleson County. Reference ---------------------------------- Driscoll, F.G., 1986, Groundwater and wells (2d ed.): St. Paul, Minn., Johnson Division, 1,089 p. Disclaimer Information ---------------------------------- This report was prepared by an agency of the U.S. Government. Neither the U.S. Government nor any agency thereof, nor any of their employees makes any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed in this report or represents that its use would not infringe privately owned rights. Reference therein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not constitute or imply its endorsement, recommendation, or favoring by the U.S. Government or any agency thereof. Although all data and software in this report have been used by the USGS, no warranty, expressed or implied, is made by the USGS, as to the accuracy of the data and related materials and (or) the functioning of the software. The act of distribution shall not constitute any such warranty, and the USGS in the use of these data, software, or related materials assumes no responsibility. For additional information, contact: Director USGS Texas Water Science Center 8027 Exchange Drive Austin, Texas 78754-4733 E-mail: dc_tx@usgs.gov