A geomorphic approach to global classification for inland wetlands

Abstract

A geomorphic classification of inland wetlands on criteria other than vegetation is proposed, based on their host landform and degree of wetness. Thus, the classification addresses the underlying structure of most inland wetlands, i.e. their landform setting and their various types of hydroperiod. Landforms host to wetlands include: basins, channels, flats, slopes and hills/highlands. Degrees of wetness include: permanent, seasonal or intermittent inundation, and seasonal waterlogging. From combining the landform type with hydroperiod, thirteen primary types of common wetlands are recognized: 1. permanently inundated basin = lake; 2. seasonally inundated basin = sumpland; 3. intermittently inundated basin = playa; 4. seasonally waterlogged basin = dampland; 5. permanently inundated channel = river; 6. seasonally inundated channel = creek; 7. intermittently inundated channel = wadi; 8. seasonally waterlogged channel = trough; 9. seasonally inundated flat = floodplain; 10. intermittently inundated flat = barlkarra; 11. seasonally waterlogged flat = palusplain; 12. seasonally waterlogged slope = paluslope; and 13. seasonally waterlogged highlands = palusmont. Water, landform and vegetation descriptors can augment the nomenclature of the primary units: e.g. salinity of water; size and shape of landform; and organisation, structure and floristics of vegetation. The classification can be used in many settings, regardless of climate and vegetation types. Using the approach adopted in this classification, in principle, more landform types and degrees of wetness, if necessary, can be added to the system to define additional wetland types.