HYDROGEOMORPHIC CLASSIFICATION (HGM) (BRINSON)

I. CLASSIFICATION SYSTEM

A. Emphasizes: hydrology, geomorphology

B. Independent of: biogeographic distribution of species

(Uses information external to wetland.)

C. Supposed to aggregate wetlands with similar functions

II. COMPONENTS

A. Geomorphic setting (topographic location)

B. Water source and its transport (precipitation, surface, groundwater)

C. Hydrodynamics (direction and strength of flow)

III. GEOMORPHIC SETTING

A. Depressional wetlands

B. Peatlands

C. Riverine

D. Fringe

E. Slope

F. Flats

IV. WATER SOURCE

A. Biotically important water factors

B. Hydrologic inputs: precipitation, groundwater, surface or near-surface flows

C. Resultant wetlands

groundwater = groundwater slope or depressional wetlands

stream channel = fringe or riverine

low surface flows and low groundwater flows = bog, fen

V. HYDRODYNAMICS

A. Definition: motion of water and capacity to do work

B. Vertical flux (depressional, evapotranspiration, rain)

C. Unidirectional (riverine, streamflow)

D. Bidirectional, surface or near surface (fringe wetlands, tides, wind, storage)