Lesson 4 Activity

Assignment 4.1

Explore and use National Wetlands Inventory (NWI) (accessed 6-21-14) with the Wetland Mapper feature.

To complete Assignment 4.1, you will choose two aquatic classification systems —that you want to explore— which will allow a comparison between them, and classify five aquatic features (i.e., wetlands, river, lake, estuary, etc.), which occur in an area you designate (e.g., ecoregion, state, county, etc.). It might be best to do this in an area with which you are familiar, or even better, one you can physically visit, so you can view and explore the wet places you are classifying. The Reference Materials page of this lesson lists a number of readings that describe some common classification systems. Alternative classification systems are available for geographic regions outside the U.S. - Please contact instructor.

The intent, then, is to use the NWI’s Wetland Mapper to zoom in on an area of your choosing, locate five aquatic features, and either record their designated type, or preferably, try to classify them yourself. If you use Cowardin et al. (1979), which is featured in the Wetland Mapper, then record the types for your five features, and then reclassify them using an alternative system (e.g, Brinson, Ramsar, etc.). If you live outside the U.S., or wish to classify systems elsewhere, then use Google Earth (or Google Maps, clicking on the “Earth” button in the lower left to reveal aerial imagery) to locate an area, zoom in to view and choose five aquatic features, and then classify them based on two of the systems mentioned.

You can compare among more than two systems if you so choose. It is suggested that students from the U.S. choose to compare the Cowardin et al. (1979) system, which is widely used, and the system used for NWI mapping, with the hydrogeomorphic (HGM) system of either Brinson (1993, freshwater types only for the U.S.) or Brooks et al. (2011, fresh and marine types of the Mid-Atlantic region of the U.S.). Other systems recommended include Ramsar 2009 (suitable for worldwide use) or Warner and Rubec (1997) for Canada.

You should read through the listed manual, document, or web instructions for each of the systems you choose to become familiar with the terminology, and how the classification system works. Most are hierarchical. That is, you start with the most general (e.g., system for Cowardin et al. 1979, class for Brinson 1993 or Ramsar 2009/2013), and move down through increasingly detailed subclasses. Note that many of the systems use terms that may seem unusual – riverine upper perennial is used in NWI to indicate a headwater stream and wetland. This is to avoid using local terms that are not universally known by most people. For example, vernal pool (a small pond used for breeding by some species of amphibian) can be called or labeled as a “temporary pond” or “isolated depression”, with a hydrologic modifier such as “ephemeral” or “seasonal” (because many of them dry out during the summer or dry season), and a vegetation designation of “forested” or “emergent” (the latter being grass-like plants that emerge above the surface of the water).

To get started with Wetlands Mapper of the National Wetlands Inventory (NWI):

• click on Wetland Mapper link on the NWI home page;
• read through the instruction manual and/or Frequently Asked Questions (FAQs);
• in step #3, click on "Wetland Mapper V2" thumbnail;
  • if you are having problems accessing the Wetland Mapper V2 site, try the following URL: https://www.fws.gov/wetlands/data/Mapper.html
• you should see a map of the U.S.

You can choose an area in several ways. You can provide an address, landmark, or latitude-longitude (fill in FIND LOCATION box in upper right), but it is easiest to use the zoom bar on the left, and then click and drag on the map to locate your area of interest. Once you are in the vicinity, you can click on the Available Layers on the right to highlight features of interest. SPOILER ALERT: The default layer is wetlands, so when you zoom in, you will see the type label. If you would rather try to classify the visible types yourself, click off the wetlands layer first, then click it on later to check your results.

If you want some assistance initially, I recommend just using the default wetlands option, but riparian areas can also be selected (this is a relatively new addition to the system, and will not appear in the original Cowardin et al. (1979) reference). If you do click on the wetlands option, and zoom in close enough, you will see the type designation chosen by the aerial photo-interpreter. They have essentially already done your work for you. There is, however, more to learn about the code and characteristics behind it. Click on any of the code, and it will provide additional data and an explanation (see Figure 4.1 below).

Remember, you still need to classify the five features you chose using another system. Once you choose your area of interest, you should take a screen shot and convert it to a JPEG file that you can label with the types for the two systems (see Fig. 2 in SAMPLE). You should also make a comparison table in your assignment report (see SAMPLE ASSIGNMENT – 4.1 Brooks, R. - Classifying Aquatic Ecosystems). The report should be 3-5 pages, with graphics.