Hydric Soils Online Training Series

Module 9: Landform and Landscapes – HGM and Hydric Soils
Module Description

The module focuses on the Hydrogeomorphic (HGM) system and hydric soils. The classification of wetlands in the HGM system is based on landscape position, dominant water source, and hydrodynamics – the magnitude and direction of water inflow and outflow.  Information on these parameters is contained in soils information, which is housed in the Web Soil Survey and the soils database.  While HGM interpretations are not provided directly, knowledge of soils attributes can be readily applied to make HGM class and sub-class designations.  These attributes can be used to aggregate soil map units into HGM site concepts.  A site concept is valid when all map units have similar water budgets, are in the same watershed positon, and have the same water movement vectors.  The HGM system also requires the definition of a Reference Domain, within which HGM classifications are valid.  Since soil map unit concepts are generally consistent within a Major Land Resource Area, this boundary is the first selection for the Reference Domain.  Since landscape position is more meaningfully defined as watershed position, the HUC-12 watershed scale is useful for heads-up testing of map unit aggregations. Since map units often need to be either aggregated, or disaggregated into components, the use of Digital Elevation Data is useful for performing these “lumping” or “splitting” operations.  The final result should be a HGM sub-class with associated map units, or components, which can be mapped across the MLRA extent, and which is useful for land managers and conservation planners. 

Target Audience

Wetland field practitioners who need expertise in hydric soils and seek to understand how hydric soils are formed and how to recognize and interpret the information they provide when observed in the field.

Module Learning Objectives

By taking part in this online training, participants should be able to:

  • Recognize that the classification of wetlands using the HGM system is based on landscape position, dominant water source, and hydrodynamics.
  • Understand that information on these parameters is contained in the soils information housed in Web Soil Survey and the soils database.  
  • Recognize that knowledge of soils attributes can be readily applied to make HGM class and sub-class designations.
  • Understand that attributes can be used to aggregate soil map units into HGM site concepts.  
  • Better recognize when a site concept is valid
  • Understand that the HGM system also requires the definition of a Reference Domain
  • Understand when and how specific types and uses of HGM data are useful in hydric soils work

Trainer Bio

Richard Weber, P.E. is the Wetland Hydraulic Engineer on NRCS’s National Wetland Team, housed at Fort Worth, TX. He provides hydrology support for NRCS wetland restoration programs and wetland protection policy.  He also assists with the application of wetland functions to address water quality, floodplain management, and other resource concerns.  Prior to his appointment in Fort Worth, he worked in the field in Kansas, Washington, and Nebraska.  He holds a B.S. in Agricultural Engineering from Kansas State University, and is a licensed Professional Engineer in the state of Kansas.

Presentation (Vimeo)

Link to Online Quiz

To complete this module, use the following link to access the module quiz on ClassMarker.  Once you complete and submit the quiz, it will be automatically graded and you will receive your quiz score and the correct answers.  Passing the quiz will also qualify participants to download a Certificate of Completion that the participant can submit themselves to accrediting organizations for continuing education credits.

To Take the Quiz and Receive a Certificates of Completion for this Module

Participants who both view the module presentation and complete the module quiz are eligible for an ASWM Certificate of Completion for 0.5 hours of training.

Using the ClassMarker online system, ASWM will ask you to certify that you completed viewing the entire hydric soils training module video presentation.

You will need to develop a username and password in ClassMarker. Once you click on the quiz link, you will be prompted again to provide your name and email address, which will be used to process your certificate.

To receive your certificate you must BOTH:

  1. Certify that you completed viewing of the video presentation.  Answering “no” will result in no certificate being issued.
  2. Complete all 5 quiz questions, getting three or more of the questions correct.  You will be provided three attempts to take the quiz for the module.  If at the end of your third attempt you have not been able to get three or more correct, you will not be eligible to receive a certificate.

You will be prompted to download your Certificate of Participation from ClassMarker after you complete the quiz.

Once you download your certificate, you can then submit the certificate to the accrediting organization of your choice to potentially receive continuing education units/credits.  

Please select the appropriate certificate process:

  • I am an ASWM Member:
    All ASWM members receive free Certificates of Participation for webinars.  Non-Members will be charged a processing fee of $10.00 US.  To receive your free Certificate of Participation, click here.

    If you are not a current ASWM Member, you must select the non-member certificate link to receive your certificate. 
  • I am not an ASWM Member:
    If you are not an ASWM member, please either:

A) Select the Non-member Certificate Option (to begin the module quiz, click here) to get your certificate. All non-ASWM Members are required to pay a $10.00 certificate processing fee.  You will be prompted to pay the processing fee using PayPal, with the option to sign in as either a PayPal member or as a guest (not requiring a PayPal account and using your credit card).  .  

B) We encourage you to go to the ASWM.org website and become a member so that you can receive certificates at no charge for the next 12 months.

If you have any questions, please contact Laura Burchill at or contact the ASWM office at (207) 892-3399.