Humboldt-Toiyabe National Forest Intermountain Regional Office United States Department of Agriculture R5 Remote Sensing Lab Forest Service—Engineering Adaptive Management Services Remote Sensing Applications Center Technical Report October 2004 Integration of Remote Sensing RSAC-65-RPT1 Existing Vegetation Mapping: Humboldt-Toiyabe National Forest John Gillham, Haans Fisk, Wendy Goetz, Henry Lachowski Remote Sensing Applications Center Salt Lake City, UT Prepared for: The Humboldt-Toiyabe National Forest USDA Forest Service The Forest Service, United States Department of Agriculture (USDA), has developed this information for the guidance of its employees, its contractors, and its cooperating Federal and State agencies and is not responsi- ble for the interpretation or use of this information by anyone except its own employees. The use of trade, firm, or corporation names in this document is for the information and convenience of the reader. 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For additional information, contact Henry Lachowski, Remote Sensing Applications Center, 2222 West 2300 South, Salt Lake City, UT 84119; phone: 801-975-3750; e-mail: [email protected]. This publication can be downloaded from the RSAC Web site: http://fsweb.rsac.fs.fed.us ii Table of Contents Executive Summary ........................................................................................................iv Introduction ..................................................................................................................... 1 Overview ................................................................................................................... 1 Partnership ................................................................................................................ 1 Study Area ................................................................................................................ 2 Background ............................................................................................................... 3 Methods .......................................................................................................................... 5 Project Planning ........................................................................................................ 6 Geospatial Data Acquisition ...................................................................................... 8 Image Pre-Processing ............................................................................................... 9 Field Data Collection ................................................................................................13 Office Photo-Interpreted Sites ..................................................................................13 Draft Map Review and Revision ...............................................................................15 Accuracy Assessment Design ..................................................................................16 Map Products .................................................................................................................17 Existing Vegetation Map...........................................................................................17 Dominance Types ....................................................................................................18 Canopy Closure Class .............................................................................................18 Tree Size Class ........................................................................................................18 Value-Added Products .............................................................................................18 Accuracy Assessment Results .......................................................................................19 User’s Class Accuracy (Errors of Commission) ........................................................20 Producer’s Map Accuracy (Errors of Omission) ........................................................24 Overall Map Accuracy ..............................................................................................28 Map Applications............................................................................................................29 Appropriate Uses .....................................................................................................29 Inappropriate Uses ...................................................................................................31 Conclusion .....................................................................................................................32 References ....................................................................................................................33 Appendices ....................................................................................................................35 iii Executive Summary The Humboldt-Toiyabe National Forest required continuous vegetation information across the forest (over 7 million acres) to support their Forest Plan Revision effort. A mid-level existing vegetation map and other products were developed through a partnership comprised of the Remote Sensing Applications Center (RSAC), Region 5 Remote Sensing Lab (RSL), Adaptive Management Services (AMS), and the Humboldt- Toiyabe NF with coordination from the Regional Office. RSAC and RSL provided general project management and expert vegetation mapping support, and AMS field crews collected field samples with guidance from the Humboldt-Toiyabe NF. RSAC mapped the eastern ranger districts of Austin-Tonopah, Ely, Mountain City, Santa Rosa and Ruby Mountains-Jarbidge, while RSL was responsible for mapping the western districts of Carson and Bridgeport. Both map products were designed to approximate the Forest Service mid-level vegetation mapping standards and to be stored in the Forest GIS and National databases. This report documents the innovative techniques developed by RSAC to produce a dominance type, canopy closure, and tree size class map on the eastern districts. Existing vegetation maps provide consistent baseline information about current vegetation composition, structure and patterns. This map product can be used to assist with a variety of resource planning and monitoring activities. Some appropriate applications include: ecosystem and wildlife habitat assessments, rangeland and watershed assessments, fuel load assessments, benchmark analysis, updating range allotment management plans, threatened and endangered species modeling, and recreational activity management. The vegetation map was prepared over a 13-month period for under 10 cents per acre. The map design was driven by the requirements of the Forest Plan Revision team, and involved reviewing known vegetation types, preparing a hierarchical classification system, and establishing a map legend. RSAC implemented a field sampling strategy and AMS field crews visited the sites and recorded ground-level information. RSAC entered the data into a database and evaluated it for consistency and accuracy in order to be used as training samples. An advanced map-making process that incorporated new data-mining technology, was used to create the existing vegetation map. This entailed processing geospatial data, segmenting imagery, producing an image cube and a data cube, generating complex decision trees, and creating and evaluating the map products. Geospatial data processing involved collecting, assembling, and deriving new geospatial data layers from 24 Landsat satellite images and nearly 300 Digital Orthophoto Quads. Image segmentation was performed on high-resolution imagery, which divided the landscape into homogeneous units. Climatic, spectral, and topographic layers were summarized for each homogeneous unit producing an image cube of 58 different layers. A data cube, which was produced by intersecting the training data with the image cube, was analyzed with data mining software to generate a series of complex decision trees. The decision trees were applied to the image cube that resulted in the existing vegetation map product. Draft maps were distributed to local field resource specialists for comment and review. Recommended changes and manual edits were incorporated into the map and a field based accuracy assessment was conducted on the final product. RSL mapped vegetation using similar techniques over the western districts (Carson and Bridgeport), which was crosswalked with RSAC’s map product and delivered to the Humboldt-Toiyabe NF as a consistent and continuous existing vegetation map product. Existing vegetation map products were delivered