coaltech upper olifants river catchment wetland inventory ...

3.4 Wetland classification
Wetlands can be classified according to different classification methods, based on the
hydrological functioning, fauna and / or flora composition or diversity, soil, or a combination
of these features. The classification method used mostly depends on the reason for
classification. Botanists would mostly use vegetation composition to classify wetlands,
whereas an ornithologist will mostly use bird habitat features as a defining criterion.
Ecologists are, however, more interested in the interaction of different biotic and abiotic
features within a system and will therefore use the complete system functioning as part of
the classification (Ward & Lambie 1999, Allan et al 1995, Cowardin no date, Kiai & Mailu no
date, http://dept.my.gov/wqinfo/wetlands/classification.asp). In addition, there are also
various classification methods using remote sensing, depending on the percentage open
water, type of vegetation cover and density of the vegetation cover (Dely et al 1999,
Shanmugam et al in press).
One of the most popular methods for the classification of wetlands is the fundamental
hydrological functioning of the wetland. The wetlands are therefore classified into different
hydro-geomorphic units. The hydro-geomorphic units differ from one project to another and
from one specialist to another (Ward & Lambie 1999, Kotze et al 2005). The most popular
wetland classification method used in South Africa is the classification of hydro-geomorphic
units.
The classification used by Kotze et al (2005) in WET-EcoServices is a classification using
hydro-geomorphic units. This is a useful classification method for assessment of the
functions and services of wetlands, since specific functions and services can be associated
with each unit type, depending on site specific conditions. The level 1 assessment of Wet-
EcoServices is a desktop study focussed on the hydro-geomorphic type of the wetland. The
hydro-geomorphic types specified in Wet-EcoServices include floodplain, valley bottom with
channel, valley bottom without channel, hillslope seepage feeding a water course, hillslope
seepage not feeding a water course and depressions (pans).
Palmer et al (2002) classified the wetlands into hydro-geomorphic units during the previous
wetland inventory. Six broad hydro-geomorphic units were identified. The six units are Non-
floodplain riparian, floodplain riparian, hillslope seepage, pans, other non-riparian and
artificial wetlands.
Wetland Database for UORC - 28 -