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scheme (Galloway, 1975) is based on the morpho-
logic expression of the delta interpreted as origi-
nating from the balance between fluvial, tidal and
wave forcing. The accompanying diagram thereby
includes the degree of delta front reworking by
waves and tides.
2D-profile models
Many quantitative models have been proposed that
focus on the dynamics of deltas in cross-section.
For example, Swenson et  al . (2005) studied
subaerial-subaqueous delta couplets (compound
clinoforms) and underlined the importance of
autogenic controls. Based on different combina-
tions of three dimensionless numbers, a phase
diagram for fluvio-deltaic clinoforms was sug-
gested, entailing two end-members that correspond
to river flood dominance and coastal storm domi-
nance, respectively, and supported by natural field
examples (Swenson et al ., 2005). Inherent to their
coupled fluvio-marine model, surf zone geometry
is collapsed to a vertical shoreface with a certain
breaker depth, rather than equated as a moving
boundary. Consequently, three-dimensional surf-
zone dynamics are represented only implicitly,
though in principle this is equivalent to assigning
the shoreface any (equilibrium) geometry. Other
quantitative profile models focus on the strati-
graphic response to (time-dependent) forcing
conditions but these generally do not rigorously
couple fluvial and marine morphodynamics and
often neglect wave action (e.g. Hoogendoorn et al .,
2008 and references therein).
Quantitative delta models
Quantitative delta models based on physics con-
siderations vary in terms of their governing spans
of space and time and associated aggregated level
of landform representation. For an elaborate
overview of present-day delta and shelfal models,
the reader is referred to Paola (2000) and Overeem
et al . (2005). Here, we constrain ourselves to a
short overview of quantitative models on wave-
influenced deltas to contextualise the present
model.
2D-planform models
Several quantitative models have focused on
the dynamics of deltas in planform for a varying
degree of dominance of fluvial versus marine
forcing. Komar (1973) already addressed deltaic
shoreline reorientation for different ratios of
wave energy flux and river sand supply, different
offshore wave field angles and different shore-
face slopes with a relatively simple computer
model. Bhattacharya & Giosan (2003) suggested
using the ratio of net longshore sediment
transport rate at a river mouth to average river
water discharge to determine the degree of
planform symmetry of wave-influenced deltas
and deltalobes. Following up on a numerical
model on generation of large-scale shoreline
instabilities (Ashton et  al ., 2001), Ashton &
Giosan (2007, 2011) pointed at characteristics of
the wave climate, particularly spatial distribution
of wave-angles and riverine bed-load sediment
influx to  govern wave-influenced deltaic shore-
line configuration. Different combinations of
these parameters enabled them to identify five
'prototype' planform geometries of deltas that
differ in small-scale shoreline roughness (spits)
and large-scale shoreline roughness (across-
shoreline to along-shoreline topset length ratio
and topset symmetry with respect to river-basin
axis). While these models provide insights into
the dynamics of the delta enclosure (shoreline),
the third spatial dimension is only represented
implicitly.
3D models
Recent work of Storms et al . (2007) was devoted to
morphodynamic-stratigraphic modelling of hypo-
thetical deltas under riverine forcing, including
transport of both sand and silt. Also, Edmonds &
Slingerland (2007) provided detailed insights into
the formation of sand mouth bars, the basic fabric
of many fluvial networks. Concurrently, research
has been undertaken with respect to the stability of
bifurcations, another vital component of fluvial
distributary networks (e.g. Bertoldi & Tubino, 2007;
Kleinhans et  al ., 2008; Edmonds & Slingerland,
2008). Geleynse et al . (2011) addressed the role of
the feeder system to distributary network forma-
tion in a semi-unconfined basin under wave and
tide influenced conditions. While these studies
address general delta formation and behaviour in a
genetic way, van Maren (2005) used a morpho-
dynamic model to specifically investigate plausi-
ble explanations for barrier island formation on
the  prograding Ba Lat delta platform (Vietnam),
in line with studies of Stutz & Pilkey (2002) and
Bhattacharya & Giosan (2003), that downplayed the
necessity that barrier formation be associated
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