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Digital Soil Mapping Framework for National Cooperative Soil Survey Subcommittee

Conference Call Attendees: March 13, 2006
Sharon Waltman, Jon Hempel, Amanda Moore, Corey Meier, Henry Ferguson, Don Fallon, and Haans Fisk.

Vision Statement: The National Cooperative Soil Survey (NCSS) needs standards or guidelines for generating and maintaining digital soil map products, which compromises the usefulness and effectiveness of this national investment.  A subcommittee is needed to develop a framework that provides guidelines and recommendations for producing and using digital soil map products.  The objectives of this framework are to maintain consistency and enhance scientific credibility of digital soil map products.  Once established, the coordination and communication of using digital soil map products will be improved.

Primary Objective: Form an NCSS committee or subcommittee to review existing NCSS standards for the soil and ecology business areas.  This group coordinates with other NCSS committees and workgroups such as the existing standards workgroup, and the new technology committee.  In addition, it would help surface NCSS issues to other entities including the Federal Geographic Data Committee (FGDC) committees and workgroups, and the International Union of Soil Scientists.  This committee would be responsible for developing a framework for digital mapping standards.  Some tasks may include:

  1. Review and evaluate existing soil and ecological data standards for applicability to geospatial data such as:
    1. FGDC data standards
    2. National Soil Survey Handbook
    3. Soil Survey Manual
    4. National Forestry Manual
    5. NRCS-NASIS database data dictionary
    6. USFS-TEUI Technical Guide
    7. USFS-Geospatial Data Dictionary Standards
    8. USFS-NRIS-TERRA database data dictionary
    9. Other NCSS-cooperators’ standards, guidelines, and data dictionaries
    10. Other professional organizations’ standards, guidelines, and data dictionaries
  2. Scope content for the digital soil mapping framework document.
    1. Why -- Identify specify issues and problems
    2. Who -- Define the audience within NCSS and International Partners
    3. What -- Propose an outline for the framework and specify it’s content
    4. When -- Schedule when this framework will be drafted and implemented.
    5. How -- Raise the issue to leadership; Refine and let leadership solicit proposal
  3. Provide examples of why new standards are needed for digital soil map products:
    1. Existing standards need revision
      1. FGDC data standards (outdated)
      2. Digitization standards reflect cartographic, not digital methodologies such as topology (ambiguous)
      3. FGDC lists "NASIS" standards (contradictory)
      4. The "transect" standards are based on out-dated mapping practices
    2. New standards need to be adopted
      1. Field documentation standards such as feature-level metadata
      2. Global Positioning System (GPS) accuracies, transformation methodologies, slope or aspect calculations vary.
  4. Prepare a digital soil mapping framework document. The goal of this document is to enhance scientific credibility, promote consistency, and increase standardization of digital soil map products. This document will address these issues:
    1. Identify Business Needs: (resolution, extent, and time)
      1. Address Federal Geographic Data Committee’s subcommittee or workgroups with geospatial issues such as topology, relationship-classes, thematic definitions, spatial extent, and metadata.
      2. Maximize geospatial efficiencies such as creating hierarchical map levels (National, Broad, Mid, and Base) or (Ecoregion, Subregion, Landscape, and Land Unit).
      3. Establish procedures to create and maintain seamless base layers.
      4. Recommend methods to consistently reproduce data such as interpretations, derived properties, or classifications.
    2. Discussion and evaluation of new technologies for digital soil mapping
      1. Hardware and Software
        1. Computer systems (server/desktop/portable technologies)
        2. Disk space requirements
        3. GIS and image processing packages
      2. Geospatial data sets
        1. Climatic data (PRISM, Daymet, custom models)
        2. Topographic data (DEMs, Lidar, IFSAR, etc.)
        3. Spectral imagery (MODIS, Landsat, Spot, NAIP, DOQs, airborne photography, Hyperspectral, etc.)
        4. Derived data layers (slope, aspect, soil and vegetation indices, etc.)
    3. Recommend appropriate digital mapping methods
      1. Field data collection
        1. Pedon location (GPS precision, digitizing standards)
        2. Digital data forms and formats
      2. Landscape delineation (mapping methodologies)
        1. Vector-based
        2. Raster-based
        3. Semi-automated
        4. Expert-based
      3. Map unit characterization
        1. Geographic distributions
        2. Statistical and graphical summaries
        3. Polygon and map unit trait comparisons
      4. Quality Control (QC) routine assessments that continue throughout the mapping processes
        1. Legend development
        2. Documentation requirements
      5. Quality Assurance (QA) – Correlation procedures for digital maps that take place once the map product is prepared
        1. Geospatial QA
        2. Tabular vs. geospatial (min, max, range, etc.) (field data vs. geospatial data?)
        3. Supporting documentation (point data)
        4. Seamless joins (geospatial and tabular)
    4. Specify metadata and documentation requirements for digital soil map products
  5. Develop and implementation strategy so that the application of standards are applied consistently.

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