REPORT ON THE STATUS OF THE GEORGIA COASTAL GEOGRAPHIC INFORMATION SYSTEM by Dennis B. O'Connell OPEN-FILE REPORT 91-1 DEPARTMENT OF NATURAL RESOURCES Joe D. Tanner, Commissioner ENVIRONMENTAL PROTECTION DIVISION Harold F. Rebels, Assistant Director GEORGIA GEOLOGIC SURVEY William H. McLemore, State Geologist ATlANTA 1991 REPORT ON THE STATUS OF THE GEORGIA COASTAL GEOGRAPHIC INFORMATION SYSTEM by Dennis B. O'Connell Open-File Report 91-1 Prepared in cooperation with Minerals Management Service U.S. Department of the Interior Continental Margins Study Program Subagreement No. 14-12-0001-30432-GA Department of Natural Resources Joe D. Tanner, Commissioner Environmental Protection Division Harold F. Reheis, Assistant Director Georgia Geologic Survey William H. McLemore, State Geologist Atlanta 1991 CONTENTS Page SUMMARY ................................................................................................................................ 1 IN'1R.ODUcriON .......................................................................................................................... 1 OBJECTIVE AND APPROACH................................................................................................ 2 PROORESS OF Tiffi GEORGIA COASTAL GIS .................................................................... 2 Acquisition and Installation of GIS Workstation Hardware .................................................. 3 Acquisition and Installation of GIS Workstation Software .................................................... 3 Training of Two Staff Members in the Use of the GIS Software ........................................... 3 Compilation of Database Inventory ........................................................................................ 4 Inventory of Databases Needed for Making Environmental and Mineral Resource Decisions ..... .................................................................... ............................ ..................... 5 Acquisition of Some of the Databases Identified in the Inventory ........................................ 7 Establishment of QNQC Policy and Procedures.................................................................... 7 Development of Archiving and Backup Strategies ................................................................. 8 APPENDIX A: Catalog of Available Databases as of 12/31!89 ....................~............................ 9 APPENDIX B: Quality Assurance Testing Procedures and Accuracy Assessment ................... 24 APPENDIX C: Computer File Backup Proc~ures and Policy ..................................................27 REFERENCE ..............................................................................................................................28 TABLE Table 1. Databases included in the Year Six Inventory .............................................................. 6 iii REPORT ON THE STATUS OF THE GEORGIA COASTAL GEOGRAPIDC INFORMATION SYSTEM SUMMARY The Georgia Department of Natural Resources, Environmental Protection Division has initiated the installation of a PC-compatible Geographic Information System (GIS) for the coastal region of Georgia. The Coastal GIS will be used to assist in the management of Georgia's coastal and offshore geologic resources and will also be used to manage information related to coastal geology. The work is being performed under the Continental Margins Program as a part of the Year Six Subagreement between the Georgia Department of Natural Resources, the U.S. Minerals Management Service, and the University of Texas. Work performed during Year Six has focused on the establishment of a GIS workstation and the development of an inventory of databases which are relevant to coastal geology. The present PC workstation consists of an ffiM Model 80 computer with peripherals for storing and retrieving data on magnetic tape, plotting maps, and digitizing data from pre-existing maps. PC ARC/INFO has been installed as the primary software for the Coastal GIS. Two Georgia Geologic Survey staff members have been trained in the use of this software for performing basic GIS tasks (digitizing, editing, database management, map overlay techniques, spatial analysis and routing analysis). A catalog of databases containing information related to coastal geology and resources has been compiled (see Appendix A). The compilation ofthis catalog is an ongoing process and will continue into Year Seven. Priorities for acquiring these databases have been established. The majority of the identified databases will be acquired during Year Seven or later. Policies and procedures have been established for assuring the quality of data sets that have been prepared in-house. Detailed procedures for quality assurance and accuracy assessment are presented in Appendix B. Policies have been established for archiving important data sets and backing up working files to protect them from accidental loss (see Appendix C). The current GIS facility is sufficient for most basic GIS functions, provided that the coverages which are being modified are of limited aerial extent and complexity. INTRODUCTION Geologic studies in the Georgia marine environment can be divided primarily into two domains, the coastal barrier islands and the continental shelf. Work in these areas cover a broad range of topics, including environmental, geologic framework, and mineralogic resources studies. The very diversity of these studies, their objectives, and their results have created a major problem for researchers. The information presented, the formats used, and the results are as varied as the researchers who have developed them. To date, a readily accessible, comprehensive, and uniform database is lacking. What is needed for thorough and effective resources management and research is a generalizable and "user-friendly" Geographic Information System (GIS) which can combine, reconcile, and collate the information presently available, as well as incorporate data from future studies. Such a system would insure that the data collected and information gained would be preserved with the greatestdegree ofapplicability toward an informed and comprehensive program of marine resources management. 1 The Georgia Geologic Survey has initiated the installation of a personal computer (PC)compatible Geographic Information System (GIS) for the coastal region of Georgia. The work is being performed under the Continental Margins Program as a part of the Year Six Subagreement between the Georgia Department of Natural Resources, the U.S. Minerals Management Service, and the University of Texas. This report describes the work performed under the subagreement during the period from January 1, 1989 to December 31, 1989. OBJECTIVE AND APPROACH The objective of the Year Six Project is to initiate the development of a PC-compatible GIS for the coastal area and continental shelf of Georgia. This PC-based GIS will be used for natural resource and information management in the coastal and continental shelf regions of Georgia. GIS technology has the following advantages: 1 It preserves attribute (descriptive) information related to spatial features. 2. It maintains topological relationships between features. 3. It allows the user to rapidly perform spatial analysis by merging information from unrelated sources, once this information has been digitized. In order to meet the project objective, the following approach was implemented: 1. Establish a PC-compatible GIS workstation at the Georgia Geologic Survey. This workstation will include facilities for digitizing, high-capacity data storage and retrieval, data file management, spatial analysis, and graphics output. 2. Compile an inventory ofdatabases that will be integrated into the GIS, and establish priorities for their incorporation into the Coastal GIS. 3. Acquire databases that have been identified in the inventory, and maintain an archive of these databases. 4. Establish procedures to insure the quality of databases which are digitized by the Georgia Geologic Survey, and develop strategies for protecting the database archive and computer working files through the creation of backup copies. S. Train Georgia Geologic Survey personnel in the use of the GIS. PROGRESS OF THE GEORGIA COASTAL GIS As of December 31, 1989, the following accomplishments toward the establishment of the Georgia Coastal GIS have been achieved: 1. Acquisition and installation of GIS workstation hardware. 2. Acquisition and installation of GIS workstation software. 2 3. Training of two staff members in the use of the GIS software. 4. Compilation of a database inventory. 5. Acquisition of some of the databases identified in the inventory. 6. Establishment of quality assurance and quality control (QA/QC) procedures. 7. Development of archiving and back up strategies. Each of these accomplishments is discussed in detail below. Acquisition and Installation of GIS Workstation Hardware Establishment of the workstation which will be used for GIS tasks has been completed. The present workstation consists of the following: 1. ffiM PS/2 Model 80 computer with 2MB user memory, 115MB fixed disk storage, 20 MHz math co-processor, mouse, VGA color monitor, 3.5 inch diskette drive and multi-protocol communications adapter. DOS version 3.30 has been installed as the operating system. 2. IBM model 6157-002 streaming tape drive. Compatible data storage tapes are capable of storing 125 MB of data. An adapter for the streaming tape drive has been installed on the ffiM PS/2 Model 80. 3. Hewlett Packard model 7570A Draft ProD-size plotter. 4. Calcomp model95360 digitizing table, 36.5 x 48.5 inches, with a compatible 16 button digitizing cursor. This digitizing table is capable of resolving up to 10,160 lines per inch, with an accuracy of+ or - .005 inches. Acquisition and Installation of GIS Workstation Software The PC version of ARC/INFO was selected as the primary software for the Coastal GIS. PC ARC/INFO includes modules for data capture through digitizing, interactive graphic data editing, data transfer, relational database management, map overlay, spatial analysis, and network analysis for optimum routing. ARC/INFO software is widely used by a number of Federal, State, and local agencies. Because ofits widespread use in government, databases generated by these agencies may be easily imported. In addition, databases that have been compiled using most of the common relational database management system programs may be easily imported and converted into ARC/ INFO flles. The PC ARC/INFO software has been acquired and installed and is currently operational. Training of Two Staff Members in the Use of GIS Software Two staff members attended a PC ARC/INFO starter course sponsored by the Center for 3 .Remote Sensing and Mapping Science (CRMS) at the University of Georgia. Topics addressed in the lectures and exercises included: 1. GIS applications and future trends in GIS; 2. basic functions and operations with PC ARC/INFO software; 3. data capture and editing, using the digitizer; 4. relational database construction, manipulation, and management with INFO; 5. relationship between INFO data files and graphic map features; 6. map overlay functions and map composition; 7. utilization of map overlay functions for spatial analysis, including environmental monitoring, resource management and urban planning applications; 8. optimum routing analysis. Compilation of Database Inventory A catalog of available databases which contain spatial information for the coastal region of Georgia has been compiled (see Appendix 1). The catalog includes a yariety of earth science information (geologic maps, soils maps, digital elevation models, etc.), environmental data (wetland inventory maps, vegetation maps, etc.), and planimetric data (political boundaries, roads, etc.). Many of these databases are not directly related to mineral resource management issues and will not be included in the inventory of databases that will be imported. Additional databases that were not found during Year Six will be added to the catalog as they are identified. Priorities for incorporation into the Georgia Coastal GIS have been assigned to all databases which were entered into the catalog. The priority categories are as follows: 1. Databases identified during Year Six that already exist in digital form and can be acquired without cost. 2. Databases identified during Year Six that do not currently exist in digital form but that can be readily digitized. 3. Databases identified during Year Six that already exist in digital form and for which there is a charge for acquisition. These data will be acquired as funds become available. The following priorities for incorporation into the Georgia Coastal GIS will be assigned to databases identified after the end of Year Six: 4. Databases identified after Year Six which are relevant to coastal geology, that 4 already exist in digital form, and can be acquired without cost. 5. Databases identified after Year Six which are relevant to coastal geology, that do not currently exist in digital form, but that can be readily digitized. 6. Databases identified after Year Six which are relevant to coastal geology, that already exist in digital form, and for which there is a charge for acquisition. These data will be acquired as funds become available. Inventory of Databases Needed for Making Environmental and Mineral Resource Decisions An inventory of databases that will be entered into the GIS during Year Seven was selected from the catalog of databases listed in Appendix 1. The inventory includes those databases which will be immediately useful in the preparation of other maps and coverages, plus basic geologic framework data for the coast and continental shelfofGeorgia. The databases that will be imported are described below and are also summarized in Table 1. Databases that have been incorporated into the Year Six Inventory include: Priority 1: databases already in digital form 1. Base map showing coastal counties and approximately 200 miles of the continental shelf. This base map will be compiled from pre-existing digitized databases on the PRIME computer and imported to the PC-based GIS. 2. Digital Line Graph (DLG) files (hydrography and major roads), currently in digital form at a scale of 1:100,000. DLG ftles will be used alone or in combination to construct coverages of limited aerial extent. Manipulation of individual DLG files is more efficient in terms of computer storage than trying to manipulate a large base map. Less than one week should be necessary to import all coastal DLG files. 3. County boundaries and other political boundaries in the coastal region, currently in digital form at a scale of 1:250,000. Less than one week should be necessary to import these files. 4. Land use and land cover for the coastal region, currently in digital form at a scale of 1:250,000. Less than one week should be necessary for importing these files. 5. Geology digitized from the state geologic map at a scale of1:500,000. Less than one week should be needed for importing these files. Priority 2: databases not currently in digital form 6. Lease tract/block boundaries, also known as "Official Protraction Diagrams," available through Minerals Management Service. This task may require up to one month. 5 Table 1. Databases included In the Year 81% Inventory. CoveraRe_Name Covera~e 'IVDe Data TvDes Prioritv Scale (Ul Source of Ua1a Required Time Coastal Counties Base Map Composite County outlines, 1 (line and hydrography and polygon data) roads 1:100,000 and 1:250,000 USGS, compiled byGGS 1 month Digital Une Graphs Line data: DLGs Hydrography and 1 roads 1:100,000 USGS 1week County Boundaries Polygon data County boundaries 1 1:250,000 USGS 1 week Land Use and Land Cover Polygon data Land use and land cover 1 1:250,000 USGS 1week Geology 0\ Official Protraction Diagrams Polygon data Polygon data Digitized state geologic map Boundaries for offshore lease tract blocks 1 1:500,000 GGS 2 1:250,000 MMS 1week 2months Offshore Une data Offshore 2 NA Georgia 2months Geophysical geophysical State Tracklines tracklines Univ. Locations Point data Locations for 2 NA GGS, USGS, 1 month for Cores COST and TACI'S and NOAA and Wells cores, oil and gas wells Location of Point data Vibracore, 2 NA Several 3months Shallow piston core, different Geologic dredge and grab sources Samples sample locations Approximate time required for incorporation of the database into the GIS. 7. Location of offshore geophysical tracklines. This data will be obtained from various sources. The acquisition process may take several weeks. Digitizing this data at the required accuracy should take no more than one month. 8. Locations of COST wells, oil and gas test wells, TACTS cores, and wells drilled by the Georgia Geologic Survey, plus related information (e.g., types of lithologic and geophysical logs associated with each well). Acquiring the exact locations for these wells and cores should require no more than two weeks. Digitizing these points should require less than two weeks. 9. Location of offshore vibracore, piston core, dredge and grab samples relevant to studies of heavy minerals; not yet digitized. Acquiring this data may take up to two months, except for data which is already in GGS files. Actually digitizing this data and assigning attributes to the digitized points should require no more than one additional month. Acquisition of Some of the Databases Identified in the Inventory The acquisition of databases identified in the inventory began during the last quarter of 1989. Activities during Year Seven will be directed mostly toward acquiring the remainder of the databases that are listed in the inventory. Procurement of the bulk of the remaining databases will be an ongoing process. Emphasis will be placed on acquiring those databases directly related to mining and minerals, rather than on data related to other aspects ofcoastal geology, hydrology, and non-economic earth resources. Priority 1 databases listed above should be acquired during the first half of 1990. The materials from which the priority 2 databases will be digitized (including maps and reports from various sources) will also be acquired during the fli'st half of 1990. Digitizing of these materials will begin during the first quarter of 1990. Priority 3 databases will be acquired as they are needed, and as funds become available for their purchase. The present acquisition status of each database in the catalog of available databases is given in Appendix A. Establishment of QA/QC Policy and Procedures In order to maintain the accuracy, logical consistency and completeness of spatial data sets which are digitized at the Georgia Geologic Survey, standards for digital cartographic data quality have been established and will be maintained. The standard of acceptance should be based on an assessment of the fitness of a spatial data set for use (i.e., whether or not the accuracy of the data set meets its intended purpose), rather than on an arbitrary numerical threshold of quality. The development of quality assurance procedures will be an ongoing process, and the procedures outlined in this report will be revised as needed. All data sets compiled by the GGS will be accompanied by a brief quality assessment statement (this will be stored on disk, along with the data set, as an ASCII text file). Topics addressed in this statement will include: 1. References to all data source materials (including dates), methods of derivation (e.g., whether the data was obtained by digitizing or through some other method) and transformation (e.g., rescaling, conversion from one projection to another, etc.), 7 where applicable, and dates of all information used to update the original source materials. Specific information on the map projection and geodetic control information used will also be reported. 2. Assessment of the positional accuracy of digitized map features (e.g., do locations for points, lines, arcs, and polygons on the digitized coverage match the locations of these features on the source materials), plus a description of the test employed to assess positional accuracy. 3. Determination of the topological consistency of digitized map features (e.g., do lines intersect only at permitted points, are there any duplicate arcs, etc., see Appendix B), plus a description of the method employed to assess topological consistency. 4. Assessment of the accuracy ofattributes associated with digitized map features, plus a description of the method used to assess attribute accuracy. 5. A description of the completeness of the data set, including relevant mapping criteria (e.g., minimum size thresholds for areas, widths, and lengths to be digitized.) 6. The report should indicate the person responsible for assessing the accuracy of each database. In most cases, accuracy assessment will be performed by the GIS specialist's supervisor. The form of the quality assessment statement, as well as many of the testing procedures used to assess accuracy, are derived from standardsestablished by the National Committeefor Digital Cartographic Data Standards (1987). Specific testing procedures are described in Appendix B. Development of Archiving and Backup Strategies In order to protect data tiles from accidental loss, strategies have been developed for archiving data tiles obtained from outside sources, as well as completed data flies and map coverages which are compiled in-house. Backup procedures were also developed to protect working flies from accidental loss. A summary of the current file backup and archiving strategy is presented in Appendix C. 8 APPENDICES APPENDIX A Catalog of Available Databases as of 12/31/89 The following catalog contains a list ofdatabases that are relevant to various aspects ofcoastal geology. Many of these databases are only marginally useful in the management of coastal resources, and will not be imported into the Coastal GIS unless they are needed for specific projects. Databases that will be imported into the Coastal GIS are listed in the Compilation of Database Inventory. Each entry in the catalog contains the following information: Title title of the document, report, or file that contains the data Priority: priority category, as previously defmed ~Compilation of Database Inventory) Data type: a brief description of the most significant data types contained in the database Source: agency or individual that compiled the data contained in the database Scale (l:X): map scale of the database, expressed as a ratio (NA =not applicable) Status: information regarding the processing and acquisition of the data in each database (status as of December 31, 1989) GEOLOGIC DATA Geophysical Data Title: Bulletin 109: Seismic Investigation of the Phosphate-bearing, Miocene-age Strata of the Continental Shelf of Georgia Priority: 2 Data type: Offshore geophysical tracklines; analog data: single-channel, high-resolution uniboom seismics, isopach and structure contour maps, references for core loca- tions Source: Georgia Geologic Survey (also Georgia State University) Scale (l:X): Several different scales Status: Report acquired, not digitized. Original data should be acquired from Georgia State University. Title: MGG File Numbers 02010077 (Cruise CH051), 02010078 (Cruise CH052), 02010089 (Cruise CH001), 02130001 (Cruise AT251), 02130003 (Cruise AT266), 02210001 (Cruise BE140) Priority: 2 Data type: Offshore geophysical tracklines; analog data: navigation, bathymetry Source: Woods Hole, through National Geophysical Data Center Scale (l:X): NA Status: Not yet acquired. Title: MGG File Number 03030016 (Cruise AMC1167) Priority: 2 Data type: Offshore geophysical trackline; analog data: navigation, bathymetry, magnetics, gravity 9 APPENDIX A (Continued) Source: NOAA, through National Geophysical Data Center Scale (l:X): NA Status: Not yet acquired Title: MGG File Number 04990020 (no cruise given) Priority: 2 Data type: Offshore geophysical trackline; analog data: navigation, single-channel seismics Source: U.S. Army, through National Geophysical Data Center Scale (l:X): NA Status: Not yet acquired Title: "Offshore LORAN Log" = working title (not yet published; publication expected in July, 1990) Priority: 2 Data type: Point data: LORAN locations for hardbottom environments Source: Georgia DNR, Coastal Resources Division Scale (l:X): NA Status: Not yet acquired; in press Title: MGG File Numbers 01010001 (Cruise C0101), 01010002 (Cruise C0102) Priority: 3 Data type: Offshore geophysical tracklines; digital data: navigation; analog data: naviga- tion, single-channel seismics . Source: Lamont (LOGO), through National Geophysical Data Center Scale (l:X): NA Status: Not yet acquired Title: MGG File Number 01010141 (Cruise C1902) Priority: 3 Data type: Offshore geophysical trackline; digital data: navigation, bathymetry, magnetics, gravity; analog data: navigation, single-channel seismics Source: Lamont (LDGO), through National Geophysical Data Center Scale (l:X): NA Status: Not yet acquired Title: MGG File Number 01030135 (Cruise V2807) Priority: 3 Data type: Offshore geophysical trackline; digital data: navigation, bathymetry, magnetics, gravity; analog data: navigation, single-channel seismics Source: Lamont (LOGO), through National Geophysical Data Center Scale (l:X): NA Status: Not yet acquired Title: Priority: 3MGG Flle Number020100.23 (Cruise CH046L01) Data type: Offshore Geophysical Trackline; digital data: navigation, bathymetry, magnetics, gravity; analog data: navigation, bathymetry, single-channel seismics Source: Woods Hole, through National Geophysical Data Center Scale (l:X): NA Status: Not yet acquired Title: MGG File Number 302030014 (Cruise KN031L05) Priority: 3 10 APPENDIX A (Continued) Data type: Offshore Geophysical Trackline; digital data: navigation, bathymetry Source: Woods Hole, through National Geophysical Data Center Scale (l:X): NA Status: Not yet acquired Title: MGG File Numbers 02300002 (Cruise FA017L01), 02300006, (Cruise FA025101), 02310001 (Cruise FL001L01), 02310002 (Cruise FL001L02) Priority: 3 Data type: Offshore Geophysical Tracklines; digital data: navigation, gravity Source: Woods Hole, through National Geophysical Data Center Scale (l:X): NA Status: Not yet acquired Title: MGG File Number 04990009 (no cruise given) Priority: 3 Data type: Offshore Geophysical Trackline; digital data: navigation (unprocessed); analog data: single-channel seismics Source: U.S. Army, through National Geophysical Data Center Scale (l:X): NA Status: Not yet acquired Title: MGG File Number06280003 (Cruise FAY-018) Priority: 3 Data type: Offshore Geophysical Trackline; digital data: navigation; analog data: naviga- tion, bathymetry, single-channel seismics Source: U.S. Geological Survey, through National Geophysical Data Center Scale (l:X): NA Status: Not yet acquired Title: MGG File Numbers 06910003 (Cruise P483AT), 06910004 (Cruise P583AT) Priority: 3 Data type: Offshore Geophysical Tracklines; digital data: navigation, bathymetry, gravity Source: U.S. Geological Survey, through National Geophysical Data Center Scale (l:X): NA Status: Not yet acquired Title: MGG File Number 06990006 (Cruise TD1-6) Priority: 3 Data type: Offshore geophysical trackline; digital data: navigation; analog data: navigation, common depth point seismics. Source: U.S. Geological Survey, through National Geophysical Data Center Scale (l:X): NA Status: Not yet acquired. Title: MGG File Number 09050041 (Cruise KA939014) Priority: 3 Data type: Offshore geophysical trackline; digital data: navigation, bathymetry Source: U.S. Navy, through National Geophysical Data Center Scale (l:X): NA Status: Not yet acquired Title: MGG File Number 09100001 (Cruise KEATHLEY) Priority: 3 11 APPENDIX A (Continued) Data type: Offshore geophysical trackline; digital data: navigation, bathymetry, magnetics; analog data: bathymetry, magnetics Source: U.S. Navy, through National Geophysical Data Center Scale (l:X): NA Status: Not yet acquired Title: MGG File Numbers 09100013 (Cruise KEA 07-68), 09100014 (Cruise KEA 08- 68) Priority: 3 Data type: Offshore geophysical trackline; digital data: navigation, bathymetry, gravity Source: U.S. Navy, through National Geophysical Data Center Scale (l:X): NA Status: Not yet acquired Title: MGG File Numbers 09100021 (Cruise KEA 02-69), 09100022 (Cruise KEA 03-69), 09100026 (Cruise KEA 07-69) Priority: 3 Data type: Offshore geophysical trackline; digital data: navigation, gravity Source: U.S. Navy, through National Geophysical Data Center Scale (l:X): NA Status: Not yet acquired Title: MGG File Number 10020004 (Cruise IG1501) Priority: 3 Data type: Offshore geophysical trackline; digital data: navigation, bathymetry, magnetics Source: University of Texas, through National Geophysical Data Center Scale (l:X): NA Status: Not yet acquired Title: MGG File Number 60000018 (Cruise LSSALE56) Priority: 3 Data type: Offshore geophysical trackline; digital data: navigation; analog data: navigation, bathymetry, single-channel seismics, common depth point seismics, sidescan sonar Source: Minerals Management Service, through National Geophysical Data Center Scale (l:X): NA Status: Not yet acquired Title: MGG File Number 60090001 (Cruise ECOASTI9) Priority: 3 Data type: Offshore geophysical trackline; digital data: navigation; analog data: navigation, single-channel seismics, common depth point seismics Source: Minerals Management Service, through National Geophysical Data Center Scale (l:X): NA Status: Not yet acquired Maps Title: Geology Priority: 1 Data type: Polygon data: geology Source: USGS-WRD, GA District (GGS) Scale (l:X): 500,000 Status: Processed, acquired by the Georgia Geologic Survey 12 APPENDIX A (Continued) Title: Geology Priority: 1 Data type: Polygon data: geology Source: USGS-WRD, GA District Scale (l:X): 2,500,000 Status: Processed, acquired by DNR, Information Management Title: Soils- County Priority: 1 Data type: Polygon data: soils Source: USGS-WRD, GA District (originally from Georgia DNR) Scale (l:X): Several different scales Status: Currently being processed by USGS, some acquired by DNR. Title: Open-file Atlas of Mines, Pits, and Quarries for Georgia: Coastal Plain Priority: 2 Data type: Point locations: mines, pits, and quarries Source: Georgia Geologic Survey Scale (l:X): 24,000 Status: Acquired, not digitized. . / Title: Bulletin 104: A Revision of the Lithostratigraphic Units of the Coastal Plain of Georgia: the Miocene Through the Holocene Priority: 2 Data type: Maps of marine terraces (generalized), outcrop/ subcrop of formations, type and reference localities,structural and physiographic features, core and well sites Source: Georgia Geologic Survey Scale (l:X): Several different scales Status: Acquired, not digitized Title: Information Circular 31: A Subsurface Study of Pleistocene Deposits in Coastal Georgia Priority: 2 Data type: Analog data: isopach map of Pleistocene sediments Source: Georgia Geologic Survey Scale (l:X): 2,000,000 Status: Acquired, not digitized Title: Environmental Impact Statement ES 52: Proposed 1981 Outer Continental Shelf Oil and Gas Sale No. 56 Priority: 2 Data type: Maps related to physical oceanography, meteorology, environmentally sensitive areas, undersea features, sea bottom sediments, geology, offshore leases, and offshore drill sites. Source: U.S. Department of the Interior, Bureau of Land Management Scale (l:X): 1,000,000 Status: Acquired; not digitized Cores, wells, and shallow samples Title: Project Report 14: Georgia Offshore Minerals Assessment Database Priority: 1 13 APPENDIX A (Continued) Data type: Point locations; associated depth, grain size, and heavy mineral percentage values Source: Zellars-Williams Co. (produced for the Georgia DNR and MMS) Scale (l:X): NA Status: Acquired by the Georgia Geologic Survey Title: USGS OFR 89-559 (Preliminary) Phosphorite Potential in the Continental Shelf off Georgia: Results of the TACI'S Core Studies Priority: 2 Data type: Point locations: TACI'S cores, plus locations for other offshore deep stratigraphic tests and associated data Source: U.S. Geological Survey Scale (l:X): NA Status: Data acquired; not digitized Title: GGS Well Inventory Priority: 2 Data type: GGS well identification number, county, driller, owner, and sample interval for wells drilled in Georgia (see also GGS Well Record Book) Source: Georgia Geologic Survey Scale (l:X): NA Status: Data acquired; not digitized Title: GGS Well Record Book Priority: 2 Data type: Point locations (wells): GGS well identification number, county, driller, lease, sample interval, location, elevation, and "elevation depth"(= depth below land surface?) for wells in Georgia Source: Georgia Geologic Survey Scale (l:X): NA Status: Acquired; not digitized Title: MGG File Number 01035007 Priority: 2 Data type: Point locations: offshore cores, by latitude and longitude, with descriptions Source: Lamont-Doherty Geophysical Observatory, Through National Geophysical Data Center) Scale (l:X): NA Status: Not yet acquired, except for locations / Title: Bulletin 110: Distribution of Heavy Mineral Sands Adjacent to the Altamaha Sound: a Possible Exploration Model Priority: 2 Data type: Point data: location of grab, auger, and trench samples, with mean percentages of constituents; depositional environment maps Source: Georgia Geologic Survey Scale (l:X): NA Status: In preparation, not digitized J Title: Evaluation of Heavy Mineral-bearing Nearshore Sands, Altamaha and the adjacent Nearshore Zone, Georgia Priority: 2 Data type: Point data: vibracore locations, heavy mineral percentages (total by mineral) 14 APPENDIX A (Continued) Source: Georgia Geologic Survey Scale (l:X): 250,000 Status: In preparation; not digitized Title: Information Circular 77: Petroleum Exploration Wells in Georgia 1979-1984 Priority: 2 Data type: Point locations: oil test wells drilled between 1979 and 1984, plus related data Source: Georgia Geologic Survey Scale (l:X): Several different scales Status: Acquired, not digitized Title: Information Circular 51: Petroleum Exploration Wells in Georgia Priority: 2 Data type: Point locations: oil tests (map, locations by latitude and longitude, miscellaneous well information) Source: Georgia Geologic Survey Scale (l:X): 1,095,957 Status: Acquired, not digitized Title: Information Circular 38: Petroleum Exploration in Georgia Priority: 2 Data type: Point locations: oil and gas tests 1903-1970 Source: Georgia Geologic Survey Scale (l:X): 1,095,957 Status: Acquired, not digitized Title: Information Circular 19: Oil Tests in Georgia Priority: 2 Data type: Point locations: oil test wells (map) Source: Georgia Geologic Survey Scale (l:X): 1,030,244 Status: Acquired, not digitized Title: MGG File Number 03995999 Priority: 2 Data type: Point locations: piston cores and grab samples; lithology and geologic age Source: Atlantic Oceanographic and Meteorological Labs (through National Geophysical Data Center) Scale (l:X): NA Status: Not yet acquired, except for locations Title: MGG File Number 01995999 Priority: 2 Data type: Point locations: offshore cores, by latitude and longitude, with age and lithology of cores in MGG File 01035007 Source: Lamont-Doherty Geophysical Observatory (through National Geophysical Data Center) Scale (l:X): NA Status: Not yet acquired, except for locations Title: MOO File Number 06025001 Priority: 2 15 APPENDIX A (Continued) Data type Point locations: dredge or grab samples, with texture data Source: USGS-Woods Hole, through National Geophysical Data Center Scale (l:X): NA Status: Not yet acquired, except for locations Title: MGG File Number 60925001 Priority: 2 Data type: Point location: core, with core description, organic geochemistry, paleontology, geologic age, well logs, and geotechnical information Source: Minerals Management Service, through National Geophysical Data Center Scale (l:X): NA Status: Not yet acquired, except for location Title: MGG File Number 66995999 Priority: 2 Data type: Point locations: sediment drill (with lithology and age), and grab samples Source: USGS, Atlantic-Gulf Branch ofMarine Geology, through National Geophysical Data Center Scale (l:X): NA Status: Not yet acquired, except for locations Title: Bulletin 70: Well Logs of the Coastal Plain of Georgia Priority: 2 Data type: Point locations: well locations, plus well logs Source: Georgia Geologic Survey Scale (l:X): 1,003,723 Status: Acquired, not digitized Title: Bulletin 74: Logs of Selected Wells in the Coastal Plain of Georgia Priority: 2 Data type: Point locations: well locations, plus well logs of varying accuracy Source: Georgia Geologic Survey Scale (l:X): 3,060,407 Status: Acquired, not digitized Title: Bulletin 76: Subsurface "Basement" Rocks of Georgia Priority: 2 Data type: Point Locations: wells penetrating to basement, plus lithologic logs Source: Georgia Geologic Survey Scale (l:X): 1,000,000 Status: Acquired, not digitized Title: Information Circular 56: Geologic Data of the Gulf Trough Area, Georgia Priority: 2 Data type: Point Locations: well locations by latitude and longitude, well descriptions location map Source: Georgia Geologic Survey Scale (l:X): 500,000 Status: Acquired, not digitized Title: Information Circular 25: Subsurface Geology of the Georgia Coastal Plain Priority: 2 16 APPENDIX A (Continued) Data type: Point data: locations of logged wells; Line data: thickness distribution (isopach) and structure contour maps Source: Georgia Geologic Survey Scale (l:X): 1,000,000 Status: Acquired, not digitized Title: MGG File Number 02045001 Priority: 2 Data type: Point location: dredge sample, with location and description Source: Woods Hole Oceanographic Institute, through National Geophysical Data Center Scale (l:X): NA Status: Not yet acquired, except for location Title: Manganese Phosphorites of the Blake Plateau (in Marine Mineral Deposits) Priority: 2 Data type: Point data: sample location, bathymetry, geochemistry, mineralogy (manganese), geologic age, sediment chemistry and properties Source: Data available through National Geophysical Data Center Scale (l:X): NA Status: Not yet acquired, except for location Title: Assorted Papers Associated with Cruise SP-AMC-11-67 Aboard Discoverer Priority: 2 Data type: Point data: sample location, bathymetry, geochemistry (manganese) Source: Data available through National Geophysical Data Center Scale (l:X): NA Status: Not yet acquired, except for location Title: MMBffi: USGS WH 8602 Priority: 2 Data type: Point data: sample locations, bathymetry, geochemistry (manganese) Source: USGS, through National Geophysical Data Center Scale (l:X): NA Status: Not yet acquired, except for locations Multiple data types Title: COST Well GE-l Priority: 3 Data type: Well logs, COST (Continental Offshore Stratigraphic Test) Well GE-l; depth, well logs, core and sidewall cores, lithology, petrography, grain density, paleontology, biostratigraphy, Rb-Sr ages, DST reports, miscellaneous additional data, location Source: NOAA Environmental Data and Information Service Scale (l:X): NA Status: Not yet acquired J Title: Bulletin 111: Heavy Mineral-bearing Sands from the Wicomico to Princess Anne Paleobarrier Complexes along the Georgia Coastal Plain Priority: 2 Data type: Analog maps: paleobarrier island shorelines, Pleistocene barrier complexes, geomorphology of Pleistocene - Recent barrier islands, sample locations (with 17 APPENDIX A (Continued) heavy mineral percentages), traverses Source: Georgia Geologic Survey Scale (l:X): Several different scales Status: In preparation: not digitized Title: Bulletin 87: Symposium on the Petroleum Geology of the Georgia Coastal Plain Priority: 2 Data type: Maps (basement configuration, well location, isopach, structure contour. bouguer gravity anomaly), tracklines for shallow, high-resolution seismics Source: Georgia Geologic Survey Scale (l:X): Several different scales Status: Acquired; not digitized Title: Bulletin 82: Stratigraphy and Economic Geology of the Eastern Chatham County Phosphate Deposit Priority: 2 Data type: Point locations: cores; maps: structure contour, isopach, and economic phosphate; lithologic core logs Source: Georgia Geologic Survey Scale (l:X): 177,408 Status: Acquired, not digitized Title: Bulletin 108: Construction Material Potential of the Coastal Plain of South- eastern Georgia: An evaluation Priority: 2 Data type: Polygon data: sandy soil areas, physiographic provinces. potential for aggregate production, geology. geomorphic features; point locations: deposits, sampling localities Source: Georgia Geologic Survey Scale (l:X): Several different scales Status: Acquired; not digitized Title: Information Circular 53: Second Symposium on the Geology of the Southeastern Coastal Plain Priority: 2 Data type: References for information on geophysical tracklines, deep stratigraphic tests, geologic hazards, pipeline corridors, structure contour and isopach maps Source: Georgia Geologic Survey Scale (l:X): NA Status: References only; data not acquired HYDROLOGY AND HYDROGRAPHY Title: Digital Line Graph Data for Georgia: Hydrography Priority: 1 Data type: Line data: DLG, hydrography Source: USGS-WRD, GA District (NCIC) Scale (l:X): 100,000 Status: Processed, acquired by Georgia Geologic Survey Title: Water Use Sites- Withdrawals Priority: 1 18 APPENDIX A (Continued) Data type: Point locations: water use sites Source: USGS-WRD, GA District Scale (l:X): NA Status: Processed, acquired by DNR, Information Management Title: Clayton, Claiborne, and Floridan Depth to Aquifer Priority: 1 Data type: Line data: depth to aquifer Source: USGS-WRD, GA District, and GGS Scale (l:X): 500,000 Status: Processed, acquired by DNR, Information Management Title: Floridan Aquifer Potentiometric Surface I Flow Direction Priority: 1 Data type: Line data: potentiometric and flow Source: USGS-WRD, GA District Scale (l:X): 500,000 Status: Processed, acquired by DNR, Information Management Title: Most Significant Recharge Areas Priority: 1 Data type: Polygon data: recharge areas Source: USGS-WRD, GA District (originally from GGS) Scale (l:X): 500,000 Status: Processed, acquired by DNR, Information Management Title: Stream Gaging Stations Priority: 1 Data type: Point locations: stream gaging stations Source: USGS-WRD, GA District Scale (l:X): NA Status: Processed, acquired by DNR, Information Management Title: Surface Water Quality Stations Priority: 1 Data type: Point locations: surface water quality stations Source: USGS-WRD, GA District (NWIS) Scale (l:X): NA Status: Processed, acquired by DNR, Information Management Title: Water Use Sites- Discharges Priority: 1 Data type: Point locations: water use sites Source: USGS-WRD, GA District (NPDES) Scale (l:X): NA Status: Processed, acquired by DNR, Information Management Title: Public Lands: Lakes, Reservoirs Priority: 1 Data type: Polygon data: lakes Source: USGS-WRD, GA District (NCIC) Scale (l:X): 2,000,000 19 APPENDIX A (Continued) Status: Processed, acquired by DNR, Information Management Title: USFWS Wetlands Maps Priority: 2 Data type: Paper maps: land classified as wetlands for the following 1:100,000 scale quad- rangles: Beaufort, Brunswick, Fernandina Beach, Hazlehurst, Jesup, Okeefenokee Swamp, Savannah, Wassaw Sound, Waycross Source: U.S. Fish And Wildlife Service Scale (l:X): 100,000 Status: Distribution maps available; not yet acquired Title: Digital National Wetland Inventory Maps Priority: 3 Data type: Line and polygon data: wetland areas, for the following 1:24,000 scale quad- rangles: Burroughs, Cumberland Island South, Fernandina Beach, Garden City, Glennville, Glennville NE, Glissons Millpond,Harrietts Bluff, Hinesville, Letford, Limerick NW, Meldrim SE, Me:ldrim SW, Richmond Hill, Savannah, Taylors Creek, Trinity, Waltherville, Willie Source: U.S. Fish And Wildlife Service Scale (l:X): 24,000 Status: Not yet acquired Title: NOS Digital Shoreline Data: Georgia (C8) Priority: 3 Data type: Line data: shoreline Source: NOAA/NOS, Carting and Geodetic Service Scale (l:X): "Large scale,. (see product information) Status: Not yet acquired Title: NOS Digital Shoreline Data: Small Scale, East Coast, (Dl) Priority: 3 Data type: Line data: shoreline Source: NOAA/NOS, Carting and Geodetic Service Scale (l:X): "Small scale" (see product information) Status: Not yet acquired Title: NOS Digital Shoreline Data: South Carolina (Cl) Priority: 3 Data type: Line data: shoreline Source: NOAA/NOS, Carting and Geodetic Service Scale (l:X): "Large scale" (see product infonnation) Status: Not yet acquired INFRASTRUCTURE Title: Digital Line Graph Data for Georgia: Major Roads Priority: 1 Data type: Line data; DLGs, major roads Source: USGS-WRD, GA District Scale (l:X): 100,000 Status: Processed, acquired by Georgia Geologic Survey 20 APPENDIX A (Continued) Title: Digital Line Graph Data for Georgia: Roads, Trails Priority: 1 Data type: Line data; DLGs, roads and trails Source: USGS-WRD, GA District (NCIC) Scale (l:X): 100,000 Status: Processed, acquired by Georgia Geologic Survey Title: Digital Line Graph Data for Georgia: Pipelines Priority: 1 Data type: Line data; DLGs, pipelines Source: USGS-WRD, GA District (NCIC) Scale (l:X): 100,000 Status: Processed, acquired by Georgia DNR, Information Management Title: Digital Line Graph Data for Georgia: Railroads Priority: 1 Data type: Line data; DLGs, railroads Source: USGS-WRD, GA District (NCIC) Scale (l:X): 100,000 Status: Processed, acquired by Georgia DNR, Information Management LAND USE AND LAND COVER Title: Land Use and Land Cover - Level I Priority: 1 Data type: Polygon data; land use Source: USGS-WRD, GA District Scale (l:X): 250,000 Status: Processed, acquired by DNR, Information Management Title: Land Use and Land Cover- Level II Priority: 1 Data type: Polygon data; land use Source: USGS-WRD, GA District Scale (l:X): 250,000 Status: Processed, acquired by DNR, Information Management POLITICAL DATA: GEOGRAPHIC NAMES AND BOUNDARIES Title: Geographic Names Priority: 1 Data type: Point locations: geographic names Source: USGS-WRD, GA District (NCIC) Scale (l:X): NA Status: Processed, Acquired by DNR, Information Management Title: County Boundaries Priority: 1 Data type: Polygon data: county boundaries Source: USGS-WRD, GA District (NCIC) Scale (l:X): 250,000 21 APPENDIX A (Continued) Status: Processed, acquired by DNR, Information Management Title: Public Lands: Military Reserves Priority 1 Data type: Polygon data: military reserves Source: USGS-WRD, GA District (NCIC) Scale (l:X): 2,000,000 Status: Processed, acquired by DNR, Information Management Title: Public Lands: State Parks Priority: 1 Data type: Polygon data: state parks Source: USGS-WRD, GA District (EPD- GNHI) Scale (l:X): 24,000 Status: Processed, acquired by DNR, Information Management Title: Public Lands: National Parks Priority: 1 Data type: Polygon data: national parks (includes Ft. Pulaski, Ft. Frederica) Source: USGS-WRD, GA District (originally from NPS) Scale (l:X): 24,000 Status: USGS is acquiring maps: not digitized Title: Official Protraction Diagrams (OPDs) Priority: 2 Data type: Polygon data: OPDs (boundaries for offshore lease tracts) Source: Minerals Management Service Scale (l:X): 250,000 Status: Data acquired; not yet digitized TOPOGRAPHY AND BATHYMETRY Title: Digital Elevation Model Data for Georgia: Elevation Data Priority: 1 Data type: Polygon data: Digital Elevation Model (OEM), elevation, 60 m. resolution Source: USGS-WRD, GA District (NCIC) Scale (l:X): 250,000 Status: Some processed in-house at USGS, none acquired (Note: the Coastal GIS does not currently have the correct PC ARC/INFO module for processing OEM data. This software is available, and could be acquired if needed.) Title: Digital Elevation Model Data for Georgia: Elevation Data Priority: 1 Data type: Polygon data: Digital Elevation Model (OEM), elevation, 2700 ft. resolution Source: USGS-WRD, GA District (NCIC) Scale (l:X): 250,000 Status: Processed, acquired by DNR, Information Management (see note, above) Title: Digital Elevation Model Data for Georgia: Slope Class Priority: 1 Data type: Polygon data: Digital Elevation Model (OEM), slope class Source: USGS-WRD, GA District (NCIC) 22 APPENDIX A (Continued) Scale (l:X): 250,000 Status: Some processed in-house at USGS, none acquired (see note above) Title: Bulletin 98: Historical Changes in the Mean High Water Shoreline of Georgia, 1857- 1982 Priority: 2 Data type: Nearshore and shelf bathymetry, shelf topography, shoreline changes and net erosion/accretion maps Source: Georgia Geologic Swvey Scale (l:X): Several different scales Status: Acquired; not digitized Title: NOS Hydrographic Database Priority: 3 Data type: Point data: bathymetry Source: NOAA, National Geophysical Data Center Scale (l:X): NA Status: Not yet acquired 23 APPENDIXB Quality Assurance Testing Procedures and Accuracy Assessment Assessment of Positional Accuracy An assessment of the positional accuracy ofpoints, lines, and polygons should be made for each map coverage digitized in-house. The assessment should include an assessment of the accuracy of the source or sources from which the coverage was digitized, as well as an evaluation of the accuracy of the digitizing process used to create the coverage (including any testing procedures employed). The relationship of map coordinates to a specific map projection should be clearly expressed. The geodetic standards, datum and map scale used should be recorded. Any transformations used to produce the final product should be documented. Digital map coverages that were prepared using different projections, scales, geographic data, and values of magnetic declination should be transformed to the same projection, etc. before being merged in order to reduce errors. Whenever possible, the magnitude of errors and uncertainty associated with the field location of points (e.g., core and sample locations), lines (contours, faults, formation contacts), and polygonal areas should be estimated. Any assumptions made concerning error propagation during the field mapping process should be stated. Methods used for locating points and elevations on maps (e.g., surveying, LORAN, deductive estimate) should be reponed if this information is available. Positional accuracy for digitized coverages can be assessed using one or more of the tests listed below. The most rigorous testing procedure is listed first, and the least rigorous test is presented last (this format will be used throughout the remainder of this appendix). Whenever possible, the most rigorous test feasible should be used to determine fitness for use. The results of each test, as well as any geometric or numerical thresholds of tolerance applied, should be reported. 1. Comparison to an Independent Source of Higher Accuracy. This test is generally applicable to only well-defined points. For example, it may be possible to check the location ofpoints digitized from a map (such as benchmarks, political boundary intersections, etc.) against the location of these points as determined by an accurate survey. Refer to the National Committee for Digital Cartographic Data Standards (1987) for test guidelines. 2. Comparison to the Original Data Source. In cases where the coverage has been digitized from a drafted map (or maps), the positional accuracy can be checked visually by overlaying the digitized coverage onto the original map. If the coverage contains points that have been plotted from a tabular database of map coordinates, the coordinates of the points that have been plotted should be compared to the original coordinates in the database. Where feasible, all such points should be checked. If this is impractical, points that will be spot checked should be randomly selected, recorded, and the test result for each point reported. 3. Deductive Estimate. For coverages where methods 1 and 2 (above) are not practical, a deductive estimate of the accuracy of the coverage may be acceptable. For instance, it may not be possible to directly compare a final map coverage to the original data source (e.g., another map) if the map has been rescaled or has been otherwise transformed since it was first digitized. Such estimates are usually based on the knowledge and experience of the individual assessing the accuracy of the coverage. Whenever the accuracy of a coverage is assessed by deductive estimate, the specific basis for the deduction should be explained. Errors inherent in each production step, assumptions concerning propagation of errors, and calibration tests employed in the digitizing process should be addressed. 24 APPENDIX B (Continued) Assessment of Attribute Accuracy Attributes are descriptive data that are assigned to each point, line, or polygon on a map. Examples of attributes include lengths associated with line segments, areas associated with polygons, and descriptive tenns that can be associated with points,lines, orpolygons to distinguish them from other points, lines and polygons. Specific tests which can be used to determine attribute accuracy are described below. 1. Comparison to a Source of Higher Accuracy. Attributes of digitized features whose real-world values have been accurately surveyed or otherwise determined, such as the length of political boundaries and the areas enclosed by these boundaries, can be compared to the values calculated from the survey. All tolerance thresholds should be reported, and the source of higher accuracy should be adequately referenced. This test is valid only for quantitative attribute information. Non-quantitative, descriptive attributes must be checked using another method. 2. Comparison to the Original Data Source. Comparison of the attributes of digitized features to attributes in the original data source is an appropriate test for both quantitative and non-quantitative atttibutes. For example, this procedure might be used to determine whether polygonal areas that represent specific land use categories have been correctly classified and labeled, and whether the area enclosed by each digitized polygon agrees with previous area calculations. 3. Deductive Estimate. In some cases, it may not be possible to directly compare attributes in a coverage to either an independent source of higher accuracy or to the original source of the data used to create the coverage. This may often be true for coverages created as the end product of spatial analysis. In such cases, an estimate ofattribute accuracy based on the knowledge and experience ofthe individual may be sufficient. When the deductive method is used, the basis for the deduction, including acceptance or rejection criteria, must be explained. Determination of Topological Consistency Tests for topological consistency are used to determine the fidelity of geometric relationships among lines (arcs), nodes (endpoints and intersection points of arcs), and polygons. These relationships include connectivity of arcs and nodes and the contiguity (adjacency) of polygons. A coverage is topologically consistent (or "clean") if all of the following conditions are met: 1. Arcs intersect only at nodes. 2. No lines are entered twice. 3. There are no arcs that overshoot or undershoot intended intersections. 4. All areas are completely described by arcs (i.e., the polygon is closed). 5. No polygons or lines are below minimum size thresholds. 25 APPENDIX B (Continued) 6. Cycles ofchains (arcs with a directional component) and nodes are consistent around polygons, or cycles of chains and polygons are consistent around nodes. PC ARC/INFO software contains procedures for insuring that the above conditions are met, and these procedures should be used whenever a coverage is created or modified. All of these procedures for building and maintaining topology require that tolerances are specified for minimum lengths of overshoots ("dangling arcs"), minimum distances between inter-arc and intra-arc coordinates, and minimum distances between nodes. These tolerances should be specified in the quality assessment report. 26 APPENDIXC Computer File Backup Procedures and Policy Archiving of "source" databases (Coverages/files imported from outside sources; not digitized "in-house".) a. Two separate copies should be made of all such files for archival purposes. One copy should be made for use as a "working copy: and will be kept at the Coastal GIS facility. A separate copy should be stored in another location, possibly in the Information Management Office ofthe Environmental Protection Division, Georgia Department of Natural Resources, or at the U.S. Geological Survey office in Doraville. This will insure the security of the "source" files in the event of a fire or other disaster. Maintaining a third copy at yet another location is recommended. b. protected. Tapes and diskettes on which these "source" files are maintained should be write- c. The GIS specialist will be responsible for maintaining the database archives. Backup of coverages digitized "in-house" a. While map coverages are being digitized, all files that are being modified should be backed up at the end of the day. If work is interrupted for an extended period of time (more than 1/2 hour) during a GIS work session, the files that are being used should be backed up. b. Global backups of the entire hard disk should be made at the end of every week, preferably more frequently. c. Backup copies (for archival purposes) should be made (as in part 1, above) for every coverage completed in-house. d. The GIS specialist will be responsible for backing up files in accordance with the procedure outlined above. 27 REFERENCE National Committee for Digital Cartographic Data Standards, 1987, Digital Cartographic Data Quality, inMoellering, Harold, ed., ADraft Proposed Standardfor Digital Cartographic Data: Issues inDigital Cartographic Data Standards, Report No. 8, Part ill, Nat Comm. Digital Cartog. Data Standards, Columbus, OH, p. 1-6. 28