regime that maintains (or wets) them in terrestrial settings.
In deltas, for instance, the landforms comprising wetlands
are mainly basins, flats, and channels, and the hydrological regimes that maintain them are permanent inundation,
seasonal inundation, seasonal waterlogging, intermittent
inundation, and daily to fortnightly tidal inundation. For
the terrestrial component of deltas, combining landform
type with hydrologic regime results in categories of
wetlands, which are then assigned nomenclature
(or terms) as shown in Table 1. The wetland categories
are further classified with descriptors as to size, shape,
and water salinity (Semeniuk and Semeniuk, 1995,
2011). For the tidally inundated part of the deltas, the
wetlands are identified as geomorphic units, viz., tidal
flats, beaches, tidal creeks, and spits and cheniers.
Cheniers, depending on the level to which that have
aggraded, may be inundated by tides or may have been
constructed beyond the level of tide influence and may
be inundated only by the highest river floods. As such,
they can belong either to the subaerial or to the tidal realm
of a delta.
The main categories of wetlands (and the equivalent
formal nomenclature term in brackets) that are common
within a delta using Semeniuk and Semeniuk (1995,
2011) and Semeniuk (1986) are permanently inundated
basins such as water-filled abandoned channels and
water-filled lagoons (lakes), seasonally inundated basins
such as seasonally water-filled abandoned channels and
water-filled lagoons (sumplands), seasonally waterlogged
basins (damplands), seasonally inundated flats such as
floodplains adjoining the channels (floodplains), seasonally waterlogged floodplains (palusplain), permanent
channels (rivers), seasonally flowing channels (creeks),
tidally flooded flats (tidal flats), and tidally flooded
channels (tidal creeks).
The delta as a wetland complex
The processes of delta construction result in terrain which
is essentially a nearly flat, low-lying surface close to
a water table. Deltas are sedimentary deposits that either
have shoaled to (at least) the level of the high tide or have
Estuarine Deltaic Wetlands, Figure 4 Idealized diagram showing the distribution and range of wetland types that can occur specific
to a fluvial-dominated delta, a wave-dominated delta, and a tide-dominated delta.
ESTUARINE DELTAIC WETLANDS
263
In deltas, for instance, the landforms comprising wetlands
are mainly basins, flats, and channels, and the hydrological regimes that maintain them are permanent inundation,
seasonal inundation, seasonal waterlogging, intermittent
inundation, and daily to fortnightly tidal inundation. For
the terrestrial component of deltas, combining landform
type with hydrologic regime results in categories of
wetlands, which are then assigned nomenclature
(or terms) as shown in Table 1. The wetland categories
are further classified with descriptors as to size, shape,
and water salinity (Semeniuk and Semeniuk, 1995,
2011). For the tidally inundated part of the deltas, the
wetlands are identified as geomorphic units, viz., tidal
flats, beaches, tidal creeks, and spits and cheniers.
Cheniers, depending on the level to which that have
aggraded, may be inundated by tides or may have been
constructed beyond the level of tide influence and may
be inundated only by the highest river floods. As such,
they can belong either to the subaerial or to the tidal realm
of a delta.
The main categories of wetlands (and the equivalent
formal nomenclature term in brackets) that are common
within a delta using Semeniuk and Semeniuk (1995,
2011) and Semeniuk (1986) are permanently inundated
basins such as water-filled abandoned channels and
water-filled lagoons (lakes), seasonally inundated basins
such as seasonally water-filled abandoned channels and
water-filled lagoons (sumplands), seasonally waterlogged
basins (damplands), seasonally inundated flats such as
floodplains adjoining the channels (floodplains), seasonally waterlogged floodplains (palusplain), permanent
channels (rivers), seasonally flowing channels (creeks),
tidally flooded flats (tidal flats), and tidally flooded
channels (tidal creeks).
The delta as a wetland complex
The processes of delta construction result in terrain which
is essentially a nearly flat, low-lying surface close to
a water table. Deltas are sedimentary deposits that either
have shoaled to (at least) the level of the high tide or have
Estuarine Deltaic Wetlands, Figure 4 Idealized diagram showing the distribution and range of wetland types that can occur specific
to a fluvial-dominated delta, a wave-dominated delta, and a tide-dominated delta.
ESTUARINE DELTAIC WETLANDS
263