SIGNIFICANT RECHARGE AREAS --------------------------------------------------------------------------- Table of Contents --------------------------------------------------------------------------- DOCUMENTATION REPORT FOR GIS DATABASE: MOST SIGNIFICANT GROUND-WATER RECHARGE AREAS OF GEORGIA DEPARTMENT OF NATURAL RESOURCES ENVIRONMENTAL PROTECTION DIVISION GEORGIA GEOLOGIC SURVEY Atlanta 1996 DOCUMENTATION REPORT 96-17 Table of Contents OVERVIEW GLOSSARY PART A General Description of the Database 1.0 Identification Information/Project Background 1 2.0 Data Quality Information 1 2.1 Attribute Accuracy 1 2.2 Logical Consistency 1 2.3 Completeness 1 2.4 Positional Accuracy 2 2.5 Lineage 2 3.0 Spatial Data Organization Information 2 4.0 Spatial Reference Information 2 5.0 Entity and Attribute Information 2 6.0 Distribution Information 2 7.0 Metadata Reference Information 3 Appendix A - Signatures PART B Technical Description of the Database 1.0 Identification Information 1 1.1 Citation 1 1.2 Description 1 1.3 Time Period of Content 1 1.4 Status 2 1.5 Spatial Domain 2 1.6 Keywords 2 1.7 Access Constraints 2 1.8 Use Constraints 2 1.9 Point of Contact 2 2.0 Data Quality Information 3 2.1 Attribute Accuracy Information 3 2.2 Logical Consistency Report 3 2.3 Completeness Report 3 2.4 Positional Accuracy Report 3 2.5 Lineage 3 3.0 Spatial Data Organization Information 4 3.1 Indirect Spatial Reference Method 4 3.2 Direct Spatial Reference Method 4 3.3 Point and Vector Object Information 4 4.0 Spatial Reference Information . 4 5.0 Entity and Attribute Information 5 5.1 Detailed Description 5 6.0 Distribution Information 5 6.1 Distributor 5 6.2 Resource Description 5 6.3 Distribution Liability 5 6.4 Standard Ordering Process 5 6.5 Standard Ordering Process 5 7.0 Metadata Reference Information . 5 7.1 Metadata Date 5 7.2 Metadata Review Date 5 7.4 Metadata Contact 5 7.5 Metadata Standard Name 6 7.6 Metadata Standard Version 6 PART C Digital Files Containing the GIS Database Summary of Contents of Data Cartridge 1 Data Cartridge Jacket GLOSSARY GLOSSARY Arc/Info: a popular GIS software, used by the GGS ASCII: abbreviation for `American Standard Code for Information Interchange. A set of codes for representing alphanumeric information in a format which any computer can read. attribute: a characteristic of a geographic feature. For example, if the geographic feature is a river, then an attributes of the river are the river name, the flow rate, the chemical history, etc. attribute accuracy: a measure of how well the reported characteristics actually match the real-world characteristics of a geographic feature Compact Disk Read Only Memory (CDROM): an optical media which can store 650 Mb of information. completeness: a description of the relation between the items represented in the database and the real world. For example, if a database contains water wells in Georgia, does it contain all the water wells in Georgia, or a defined sub-set of wells. If the database contains a defined subset of wells, does it contain every well in Georgia that meets the definition by which the sub-set was chosen. Content Standards for Digital Geospatial Metadata: a standard developed by the FGDC which specifies the information content of metadata for a set of digital geospatial data. database: a logical collection of interrelated information, managed and stored as a unit on a computer or other storage media. A GIS database includes data about the spatial location and shape of geographic features recorded as points, lines, areas, as well as their attributes. decimal degrees: a unit of measure for geographic coordinates. The conversion formula for decimal degrees is: Decimal Degrees = Degrees + Minutes/60 +Seconds/3600 Department of Natural Resources (DNR): a department of the government of the State of Georgia. digital: refers to the process of conversion of information into machine language so that a computer can read, write, store, and process the information. Digital Line Graph (DLG): computer files from the USGS which contain digital maps of transportation, hydrography, contours, and public land survey boundaries. digital maps: a map is an abstract representation of the physical features of a portion of the Earth's surface graphically displayed on a piece of paper. When that piece of paper is converted into a form which the computer can use, the map is then digital. diskette: a storage medium, usually measuring 3.5 inches in diameter, which is used to store or transfer information from one computer to another. FrameMaker - a popular Unix-based word processing software. Federal Geographic Data Committee (FGDC): an inter-governmental committee established through the Office of Management and Budget and charged with the responsibility to coordinate various surveying, mapping, and spatial data activities to meet the needs of the Nation. Geographic Information System (GIS): an organized collection of computer hardware, software, geographic data, and personnel designed to efficiently capture, store, update, manipulate, analyze, and display all forms of geographically referenced information. label points: a single x,y coordinate which identifies an area, and holds a place in the database wherein the area's attribute information is stored. latitude, longitude: a geographic reference system to locate positions on the Earth. Latitude and longitude are angles measured from the Earth's center to the position on the Earth's surface. Latitude measures angles in a north-south direction, while longitude measures angles in the east-west direction. lineage: information about the events, parameters, and source data which constructed a geographic database, and information about the responsible parties. logical consistency: an explanation of the fidelity of the relationships in the database. For example, for a geographic area, do the vector lines which create area boundaries join to encircle the area with no gaps. Or for example, for a particular attribute, are all the value given within a valid range. longitude, latitude: see latitude, longitude metadata: information about the content, quality, condition, and other characteristics of a database MIF: abbreviation for Maker Interchange Format, a file transfer format produced by FrameMaker National Map Accuracy Standards: a set of standards developed by the USGS which states the level of accuracy required for a map product of a particular scale. pkzip: a popular data compression software. positional accuracy: an assessment of how well the reported position of a geographic feature represents the real-world position. United States Geological Survey (USGS): a branch of the United States Department of Interior vector lines: lines which are described by x,y coordinates and are commonly used to represent linear geographic features. Each linear feature is represented as an ordered list of vertices. WordPerfect: a popular word processing software OVERVIEW This document contains a three part documentation report for a Geographic Information System (GIS) database developed, with the Arc/Info software, by the Geologic Survey Branch, Environmental Protection Division of the Georgia Department of Natural Resources. Part A is intended as a general purpose summary of the database. Part B is a more technical section included primarily for the benefit of GIS processors. Part C is a digital product which contains the database and associated documentation. The digital documentation includes a digital copy of the paper publication. This documentation report follows the "Content Standards for Digital Geospatial Metadata" (Standards) developed by the Federal Geographic Data Committee (FGDC), as published June 8, 1994. As a convenience, Parts A and B employ the outline/headings contained in the Standards. Part A and Part B are printed paper and Part C is a digital product. Part B meets the technical requirements of the Standards. The digital documentation in Part C contains two digital copies of this publication. One digital copy is stored as an ASCII file. The other digital copy is in Framemaker (MIF) format. Moreover, there are some digital documentation embedded in the database. The embedded documentation was done using the DOCUMENT aml (metadata generation tool). The DOCUMENT aml, can be used to view the embedded documentation. The DOCUMENT aml must be run within the Arc/Info, ver. 7.0 or later, software. The database in Part C consists of an Arc/Info Export file. The digital files are written on one (1) 150 megabyte data cartridge ( media)using the DG/UX version 5.4R3.10 tape archive (tar) command. A directory of the files with a short explanation are contained in the ASCII file READ.ME on the 150 megabyte data cartridge tape( media). This database was developed to satisfy specific project purposes. Users are advised to read the entire Documentation Report and to evaluate the suitability and limitations of the database for the user's purposes. PART A GENERAL DESCRIPTION OF THE GIS DATABASE: MOST SIGNIFICANT GROUND-WATER RECHARGE AREAS OF GEORGIA 1.0 Identification / Project Background This database identifies approximately 13,000 square miles (23 percent) of Georgia's land surface through which the most significant natural ground-water recharge occurs, as described in Georgia Geologic Survey Hydrologic Atlas 18: "Most Significant Ground-Water Recharge Areas of Georgia," published in 1989. Mapping of the recharge areas was based on outcrop area, lithology, soil type and thickness, slope, density of lithologic contacts, geologic structure, the presence of karst, and potentiometric surfaces. This database was intended to delimit those recharge areas where the State of Georgia should direct ground-water protection efforts. Potential users of this database are advised of the following specific cautions: 1.) Mapping at the 1:500,000 scale means that only the larger recharge areas could be included. Important smaller recharge areas cannot be shown at this scale; 2.) Since about nine-tenths of the land surface of Georgia is a recharge area, the limit of 23 percent on the most significant recharge areas is arbitrary. Areas not mapped may be locally or regionally significant. 3.) Areas mapped as recharge areas may include small areas of impermeable soils that limit recharge. The data source for the GIS database was the publication mylars (black separate linework) from Hydrologic Atlas 18. 2.0 Data Quality This section (2.0 - 2.5) contains information about the lineage, positional accuracy, attribute accuracy, logical consistency, and completeness of the database. 2.1 Attribute Accuracy Attributes (aquifer systems names) were checked by visual inspection through a comparison of a same-scale printout of the database to the published map, Georgia Geologic Survey Hydrologic Atlas 18, "Most Significant Ground-Water Recharge Areas of Georgia," published in 1989. Detected errors were corrected and after repeated inspections it is believed that attribute accuracy is excellent, with no known errors. 2.2 Logical Consistency Color shades were chosen so that when plotted, the aquifer system unit colors would match as closely as possible the published map, Most Significant Ground-Water Recharge Areas of Georgia. A visual inspection for attribute errors was conducted when the map was plotted and aquifer system units were compared to the published map. Detected attribute errors were corrected. The database was drawn on the computer terminal screen and overlaid with existing state and county political boundaries to compare spatial and projection accuracy. No corrections were necessary. 2.3 Completeness This database covers the entire state of Georgia. 2.4 Positional Accuracy Positional accuracy is unknown, but it is estimated that feature locations are accurate within +/- one-half mile, which equals approximately .07 inches on a 1:500,000 scale map. 2.5 Lineage The source document for the recharge areas database was the black line drawing on mylar film used for the publication of Hydrologic Atlas 18, "Most Significant Ground-Water Recharge Areas of Georgia" at a scale 1:500,000. This drawing was converted to an electronic product by an independent contractor . The source map was scanned into digitized area (raster) files which were converted into digital line (vector) files. The vectorized file for the map was developed and was transmitted to the Georgia Geologic Survey on 9 track tape. The data was imported from the tape into the GIS system and was processed. Files were plotted at a scale of 1:500,000 and overlaid with the publication mylars for Hydrologic Atlas 18 for inspection. The database was overlaid with existing state political boundaries to compare projection and spatial accuracy. No corrections were necessary. Attributes (aquifer system names) were typed in at the keyboard. Polygon linework and attributes were plotted at a large scale so that attributes could be checked and corrected. Color shades were chosen and typed in at the keyboard so that when plotted, the aquifer system unit colors would match as closely as possible the published "Most Significant Ground-Water Recharge Areas of Georgia" map. A visual inspection for attribute errors was conducted when the map was plotted and aquifer system unit colors were compared to the published map. Alan Sandercock, Georgia Geologic Survey, reviewed the final database and map product for attribute and vector errors. 3.0 Spatial Data Organization Information This database delineates the most significant recharge areas (aquifer systems) mapped at a scale of 1:500,000 for the entire state of Georgia. The areas are represented digitally as polygons, each with a label identifying the aquifer system. 4.0 Spatial Reference Information This database is stored in the Albers Conic Equal Area projection with units in meters. Further information on the specific parameters used can be found in Part B, Section 4.0. 5.0 Entity and Attribute Information Each polygon in the database has one attribute which identifies the major aquifer system delimited by the polygon. 6.0 Distribution Information This documentation report, including this database, is maintained by the Georgia Geologic Survey in their Technical Files. 7.0 Metadata Reference Information The metadata is incorporated within this publication, DOCUMENTATION REPORT 96-17. Part B, the Technical Section of this publication, meets the "Content Standards for Digital Geospatial Metadata" as published by the Federal Geographic Data Committee on June 8, 1994. APPENDIX A - SIGNATURES [Image] PART B TECHNICAL DESCRIPTION OF THE DATABASE: MOST SIGNIFICANT GROUND-WATER RECHARGE AREAS OF GEORGIA 1.0 Identification Information 1.1 Citation 8.1 Originator: Georgia Geologic Survey 8.2 Publication Date: 1996 8.4 Title: DOCUMENTATION REPORT 96-17 Most Significant Ground-Water Recharge Areas of Georgia 8.5 Edition: Version 1 8.6 Geospatial Data Presentation Form: GIS Database 8.7 Series Name: Most Significant Ground-Water Recharge Areas of Georgia 8.8.1 Publication Place: Atlanta, Georgia 8.8.2 Publisher: Georgia Geologic Survey 8.10 Online Linkage: Not Available 1.2 Description 1.21 Abstract: This database identifies approximately 13,000 square miles (23 percent) of Georgia's land surface through which the most significant natural ground-water recharge occurs, as described in Georgia Geologic Survey Hydrologic Atlas 18: "Most Significant Ground-Water Recharge Areas of Georgia," published in 1989. Mapping of the recharge areas was based on outcrop area, lithology, soil type and thickness, slope, density of lithologic contacts, geologic structure, the presence of karst, and potentiometric surfaces. This database was intended to delimit those recharge areas where the State of Georgia should direct ground-water protection efforts. Potential users of this database are advised of the following specific cautions: 1.) Mapping at the 1:500,000 scale means that only the larger recharge areas could be included. Important smaller recharge areas cannot be shown at this scale; 2.) Since about nine-tenths of the land surface of Georgia is a recharge area, the limit of 23 percent on the most significant recharge areas is arbitrary. Areas not mapped may be locally or regionally significant. 3.) Areas mapped as recharge areas may include small areas of impermeable soils that limit recharge. The data source for the GIS database was the publication mylars (black separate linework) from Hydrologic Atlas 18. 1.2.2 Purpose: This GIS database was developed for the Environmental Protection Division for use in analysis to support EPD's environmental protection programs. 1.3 Time Period of Content 9.1.1 Calendar Date: 1989 1.3.1 Currentness Reference: Davis, K.R., Donahue, J.C., Hutcheson, R.H., and Waldrop, D.L., 1989, Most Significant Ground-Water Recharge Areas of Georgia, Georgia Geologic Survey Hydrologic Atlas 18, one sheet. Scale 1:500,000. 1.4 Status 1.4.1 Progress: Complete 1.4.2 Update Frequency: none 1.5 Spatial Domain 1.5.1 Bounding Coordinates 1.5.1.2 West Bounding Coordinate: -186032.500 1.5.1.3 East Bounding Coordinate: 239198.406 1.5.1.3 North Bounding Coordinate: 1326422.625 1.5.1.4 South Bounding Coordinate: 838474.875 1.6 Keywords 1.6.1 Theme 1.6.1.1 Theme Keyword Reference: GEOREF Thesaurus and Guide to Indexing, Second Edition. 1978. American Geological Institute. 1.6.1.2a Theme Keyword: aquifer 1.6.1.2b Theme Keyword: water quality 1.6.1.2c Theme Keyword: ground water 1.6.1.2d Theme Keyword: recharge 1.6.2 Place 1.6.2.2a Place Keyword: GA 1.6.2.2b Place Keyword: Georgia 1.6.2.2c Place Keyword: USA 1.7 Access Constraints: Distribution constraints, see 1.9 1.8 Use Constraints: Scale 1:500,000 1.9 Point of Contact 10.1.1 Contact Person: Alan Giles 10.1.2 Contact Organization: Georgia Geologic Survey 10.3 Contact Postion: Information Geologist 10.4. Contact Address 10.4.2a Address: Agriculture Building, Rm 400 10.4.2b Street: 19 Martin Luther King, Jr Boulevard 10.4.3 City: Atlanta 10.4.4 State: Georgia 10.4.5 Postal Code: 30334 10.4.6 Country: USA 10.5 Contact Voice Telephone: (404) 657-6127 10.7 Contact Facsimile Telephone: (404) 657-9425 10.8 Contact Electronic Mail Address: alan_giles@mail.dnr.state.ga.us 10.9 Hours of Service: 8:00 a.m. - 4:30 p.m. EST 2.0 Data Quality Information 2.1 Attribute Accuracy 2.1.1 Attribute Accuracy Report: Attribute accuracy is excellent, with no known errors. 2.2 Logical Consistency Report: Color shades were chosen so that when plotted, the aquifer system unit colors would match as closely as possible the published map, "Most Significant Ground-Water Recharge Areas of Georgia". A visual inspection for attribute errors was conducted when the map was plotted and aquifer system units were compared to the published map. Detected attribute errors were corrected. The database was drawn on the computer terminal screen and overlaid with existing state and county political boundaries to compare spatial and projection accuracy. No corrections were necessary. 2.3 Completeness Report: This database covers the entire state of Georgia. 2.4 Positional Accuracy: Positional accuracy is unknown, but it is estimated that feature locations are accurate within +/- one-half mile, which equals approximately .07 inches on a 1:500,000 scale map. 2.5 Lineage 2.5.1a Source Information 2.5.1.1 Source Citation: Georgia Geologic Survey 2.5.1.2 Source Scale Denominator: 500,000 2.5.1.3 Type of Source Media: publication mylars 2.5.1.5 Source Citation Abbreviation: GGS 2.5.1.6 Source Contribution: GGS performed data processing into Arc/Info of the data and documented the data according to GGS standards, 2.5.2a Process Information: Procedures used to create or automate data: (Note: Because documentation is being prepared 6 years following database creation, procedures described are general procedures that were followed. Electronic log files were destroyed, so exact procedures and tolerances used are unknown.) The source document for the recharge areas database was the black separate line-work used for the publication of the "Most Significant Ground-Water Recharge Areas of Georgia" map, 1989 scale 1:500,000. This separate was scanned and vectorized by an independent contractor. The vectorized product was delivered on 9-track tape in ARC/INFO export format. The data was imported using the ARC/INFO IMPORT command. Tics were added manually in AE to the file. The file was plotted at a scale of 1 and overlaid with the publication mylar to ensure vector accuracy. An empty coverage was created using the CREATE command. Latitude longitude coordinates in decimal degrees were manually entered into the empty .TIC file in INFO for each registration point. Using the TRANSFORM command the files were converted from scanner units (cm.) to decimal degrees. The files were then PROJECTED into UTM, zone 16, and topology built using the BUILD POLY command. The database was overlaid with existing state political boundaries to ensure projection accuracy. The statewide coverage was PROJECTED into the LAMBERT projection and overlaid with the publication mylar source map. The statewide database was checked for dangles using the NODEERROR command. Dangles were corrected manually in AE by either extending the dangling vector or selecting and deleting the overshot vector. Polygon labels were added using the CREATELABELS command. The ADDITEM command was used to add AQUIFER as an item in the .PAT file. Attributes were added manually in AE by selecting a label point using the SELECT command and using the CALC command to enter the correct attribute. The LABELERRORS command was used to check for and correct unlabeled polygons. A visual inspection for attribute errors was conducted when the map was plotted and aquifer system units shaded appropriately, so that the AQUIFER SYSTEM unit colors would match as closely as possible the published Most Significant Ground-Water Recharge Areas of Georgia map, 1989, scale 1:500,000. Detected errors were corrected. Alan Sandercock, Georgia Geologic Survey, reviewed the final database and map product for attribute and vector errors. The database was projected into the ALBERS equal area projection for storage in the library system maintained at the Center for Spatial Analysis Technologies at Georgia Tech. 3.0 Spatial Data Organization Information: 3.1 Indirect Spatial Reference Method: dms 3.2 Direct Spatial Reference Method: polygon 3.3 Point and Vector Object Information 3.3.1 SDTS Terms Description: 3.3.1.1 Object Type: polygon 3.3.1.2 Object Count: 934 3.3.1.1 Object Type: Universe Polygon 3.3.1.2 Object Count: 1 4.0 Spatial Reference Information: 4.1 Horizontal Coordinate System Definition: Albers Conic Equal Area Albers_Conical_Equal_Area Standard_Parallel: 29.5 Standard_Parallel: 45.5 Longitude_of_Central_Meridian: -83.5 Latitude_of_Projection_Origin: 23 False_Easting: 0.00000 False_Northing: 0.00000 4.1.1.1 Latitude Resolution: +/- one half mile 4.4.4.2 Longitude Resolution: +/- one half mile 4.1.1.3 Geographic Coordinate Units: meters 4.1.4 Geodetic Model 4.1.4.1 Horizontal Datum Name: North American Datum of 1983 (NAD83) 4.1.4.2Ellipsoid Name: GRS 80 4.1.4.3 Semi-major Axis: 6378206.4 4.1.4.4 Denominator of Flattening Ratio: 294.98 5.0 Entity and Attribute Information: 5.1 Detailed Description 5.1.1 Entity Type 5.1.1.1 Entity Type Label: recharge.pat 5.1.1.2 Entity Type Definition: Polygon attribute table 5.1.2 Attribute 5.1.2.1 Attribute Label aquifer 5.1.2.2 Attribute Definition: aquifer system name 5.1.2.4 Attribute Domain Values: character 6.0 Distribution Information: 6.1 Distributor: See Point of Contact, 1.9 6.2 Resource Description: DOCUMENTATION REPORT 96-?? 6.3 Distribution Liability: Users must assume responsibility to evaluate the usability of this data for their purposes. 6.4 Standard Ordering Process: Contact the Georgia Geologic Survey, see 1.9 6.5 Custom Order Process: Contact the Georgia Geologic Survey, see 1.9 7.0 Metadata Reference Information: 7.1 Metadata Date: 1996 7.2 Metadata Review Date: 05/15/96, by Alan Sandercock, GGS 7.2 Metadata Review Date: 05/28/96 by Roger Carter, GGS 7.4 Metadata Contact: 10.1.1 Contact Person: Victoria Trent 10.1.2 Contact Organization: Georgia Geologic Survey 10.3 Contact Position: Senior Geologist 10.4 Contact Address 10.4.2 Address: 19 Martin Luther King, Jr. Dr. SW 10.4.3 City: Atlanta 10.4.4 State: Georgia 10.4.5 Postal Code: 30334 10.4.6 Country: USA 10.5 Contact Voice Telephone: (404) 656-3214 10.7 Contact Facsimile Telephone: (404) 657-8379 10.8 Contact Electronic Mail Address: vptrent@mail.dnr.state.ga.us 10.9 Hours of Service: 8:00 a.m. - 4:30 p.m. EST 7.5 Metadata Standard Name: FGDC Content Standards for Digital Geospatial Metadata 7.6 Metadata Standard Version: 6/8/94 PART C THE DIGITAL FILES CONTAINING THE GIS DATABASE: MOST SIGNIFICANT GROUND-WATER RECHARGE AREAS OF GEORGIA SUMMARY STATEMENT / DESCRIPTION OF THE CONTENTS OF PART C The digital files are written on the enclosed 150 megabyte data cartridge. The disk is in DG/UX version 5.4R3.10 tar (tape archive) format and contains the following: 1. READ.ME - an ascii file which is a digital copy of this summary. 2. DOCUMENT.ASC - an ascii file which is a digital copy of this publication. 3. DOCUMENT.MIF - a digital copy of this publication, in Framemaker format. 4. RECHARGE.E00 - the GIS database of the ground-water monitoring network in ARC/INFO export format