This file was created by scanning the printed publication. Errors identified by the software have been corrected; however, some errors may remain. United States Department ofAgricultu re A Primer on Evaluation and Use of Natural Resource Information for Corporate Data Bases Forest Service General Technical Report W0-62 0 I I I I I I I lo I I The cover shows an old USDA Forest Service photograph of a range conservationist evaluating one of his sheep. Like a shepherd, the USDA Forest Service has a huge flock of data that must be evaluated before it can be used. This primer provides suggestions for conducting such an evaluation. United States Department of A Primer on Evaluation and Agriculture Forest Service Use of Natural Resource General Technical Information for Corporate Report W0-62 March 1995 Data Bases Technical Coordinators H. Gyde Lund, Research Forester, Forest Inventory, Economics, and Recreation Research Staff, USDA Forest Service, Washington, DC Charles E. Thomas, Research Forester, Southern Forest Experiment Station, USDA Forest Service, New Orleans, LA Contributing Authors Robert G. Bailey, Program Manager, Land Management Planning Staff, Washington Office Detached, USDA Forest Service, Fort Collins, CO James E. Brickell, Forest Mensurationist (retired), Northern Region, USDA Forest Service, Missoula, MT William H. Clerke, Remote Sensing Specialist, Southern Region, USDA Forest Service, Atlanta, GA RobertS. Cunningham, Branch Chief, Programs and Legislation Staff, USDA Forest Service, Washington, DC Raymond L. Czaplewski, Mathematical Statistician, Rocky Mountain Forest and Range Experiment Station, USDA Forest Service, Fort Collins, CO Susan J. DeLost, Cartographer, Northeastern Area State and Private Forestry, USDA Forest Service, Morgantown, WV Fran Evanisko, Cartographer, USDI Bureau of Land Management, Sacramento, CA Harold R. Greenlee, Cartographer Supervisor, Southern Region, USDA Forest Service, Atlanta, GA Paul Howard, GIS Specialist, Pacific Northwest Region, USDA Forest Service, Portland, OR Randy Moore, .Deputy Forest Supervisor, Eastern Region, USDA Forest Service, Rolla, MO Jerry F. Ragus, Regional Soil Scientist, Southern Region, USDA Forest Service, Atlanta, GA Brian M. Spears, Forest Health Analytical Biologist (GIS), Southern Region, USDA Forest Service, Asheville, NC Wayne Valentine, Photogrammetrist (retired), Geometronics Service Center, USDA Forest Service, Salt Lake City, UT Lund, H. Gyde, and ChaMes E. Thomas (Technical Coordinators). March 1995. A Primer on Evaluation and Use of Natural Resource Information for Corporate Data Bases. USDA Forest Service, Washington Office, General Technical Report W0- 62. Washington, DC 168 p., illus. This primer provides resource inventory specialists with information on how to evaluate existing natural resource- information and how to use it in preparing new resource inventortes. Subjects covered indude determining information needs, finding ex!sllng lnformaUon, determining its utility, evaluating Its suitability and quality, and incorporating It into new geographic information systems. Keywords: corporate data bases, geographic information systems, resource inventories, Inventory reports, spatial data bases, nonspatial data bases, maps, overlays. remote sensing, aerial photos, aerial imagery, information sources, data utility, data suitability, data quality, data conversion, data updating The U.S. Department of Agriculture (USDA) prohibits discrimination In its programs on the basis of race, color, national origin, sex, religion, age, disability, political beliefs, and marital or familial status. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program information (Braille, large print, aUdio­ tape, etc.) should contact the USDA Office of Communications at (202) 720-5881 (voice) or (202) 720-7808 (TDD). To file a complaint, write the Secretary of Agriculture, U.S. Department of Agriculture, Washington, DC 20250, or call (202) 720-7327 (voice) or (202) 720-1127 (TDD). USDA is r n equal employment opportunity employer. Contents v Preface vii Abbreviations 1 Chapter 1: Using This Primer Make Believe 3 Reality 7 Chapter 2: Determining Information Needs 7 Needs for Resource Management Decisions 9 Needs Specific to Corporate Data Bases 9 Advantages of Corporate Data Bases 10 Disadvantages of Corporate Data Bases 10 Needs Specific to Geographic Information Systems 15 Needs Specific to Future Resource Inventories 15 Summary 17 Chapter 3: Finding Sources of Information 17 Kinds of Information 17 Personal Knowledge 18 Inventory Reports and Data Bases 19 Maps, Overlays, and Computer Spatial Data Bases 19 Remote Sensing 23 Other Georeferenced Data 23 Locations oflnformation 26 Documenting Information 27 Summary 29 Chapter 4: Determining Data Utility 30 Basic Concepts 30 Information and Data 32 Classification Systems 34 Suitability and Quality 35 Accuracy Standards 37 Major Categories of Error Sources 38 Source Errors 39 Processing Errors 39 Use Errors 39 Specific Issues 39 Nonspatial Data Bases 41 Spatial Data Bases 48 Summary 49 Chapter 5: Evaluating Data Suitability and Quality 49 Data Suitability 51 Thematic Content 51 Resolution 52 Location 52 Data Quality 53 Strategies 56 Methods 58 Quality of Content iii 62 Conversion and Update Issues 63 Benefit/Cost Analysis 64 Nonspatial Data 64 Personal Knowledge 65 Inventory Reports and Data Bases 66 Spatial Data 66 Maps and Overlays 74 Remote Sensing Imagery and Satellite Classification 82 Summary 85 Chapter 6: Incorporating Existing Information 86 Converting Data for GIS and Corporate Data Bases 86 Personal Knowledge 86 Aerial Photos and Imagery 88 Maps and Overlays 93 Computer Spatial Data Bases 94 Inventory Data Bases and Reports 95 Updating and Maintaining Existing Information 95 Aerial Photos and Imagery 96 Maps and Overlays 97 Computer Spatial Data Bases 98 Inventory Data Bases and Reports 99 Spatial Information from Different Sources 109 New Mapping and Inventory Projects 110 Aerial Photos and Imagery Ill Maps and Overlays 112 Computer Spatial Data Bases 114 Inventory Plot Data, Data Bases, and Reports 119 Summary 121 Chapter 7: Building Better Data Bases 123 References 133 Appendix: Summary of Remote Sensing Sources 141 Bibliography 147 Glossary iv Preface The USDA Forest Service is about to embark on an agencywide implementation of geographic information system (GIS) technology and corporate data bases. GIS's and corporate data bases can be invaluable tools for monitoring, protecting, and managing the country's forest and rangeland resources. The value of these tools in meeting specific requirements will largely depend on the quality and usefulness of the informa­ tion included in the data bases. Much information exists about natural resources in the form of reports, maps, over­ lays, imagery, personal knowledge, and data bases. It is usually more economical to use existing information, to the extent practical, than to collect new data, but, in some cases, new data are needed. Evaluation of existing information is important either when designing a GIS or corporate database or when a new information requirement is being defined that will use an existing GIS or corporate database. What information is needed? What is available? Are the resource data adequate, or do new data need to be collected? These are some of the questions resource and informa­ tion specialists face. Starting in 1990, the Forest Service's, Washington Office Geo­ graphic Information System Steering Committee, through the Timber Management and Information Systems and Technology Staffs, commissioned a task group to de­ velop a primer to address these questions. During that year, a number of outlines of the proposed primer's content were devel­ oped and circulated within the Forest Service for review. Agency specialists in remote sensing, GIS, cartography, information systems, and resource inventory were recruited to write the primer. In May 1993, a draft was sent to selected Forest Service personnel and to internationally recognized authorities for peer review. This volume incorpo­ rates the comments and suggestions received from that peer review. It is designed to benefit any person or agency in the process of building corporate data bases, GIS's, or planning inventories. It is important to learn from the past. When the Forest Service first started the plan­ ning process under the National Forest Management Act of 1976, its field units were instructed to use existing information to build their data bases. In some instances, the existing data were outdated or inappropriate for integrated forest planning. Using this data was a costly error resulting in delays in implementation as new inventories were made and forest plans redone. This primer is intended to provide managers and re­ source specialists with the guidance necessary to build corporate and GIS data bases that will meet the agency's needs now and in the coming century. v This page intentionally left blank. Abbreviations AVHRR Advanced very high resolution radiometer BA Basal area BW Black and white (panchromatic) photographs CFF Cartographic feature file CI Confidence interval CIR Color infared dbh Diameter at breast height (4.5 ft [1.3 m]) DBMS Database management system DEM Digital elevation model DLG Digital line graph EOSAT Earth Observation Satellite Corporation EROS Earth Resources Observation Satellite Data Center FIA Forest Inventory and Analysis Unit FGDC Federal Geographic Data Committee FPM USDA