It is interesting to note that the increase in water discharge transiting the interior of the delta have combined with the decrease in sediment load due to damming to keep sediment load directed toward the delta plain quite constant with ∼2.1 MT/yr for the Danube natural system
load at the delta of ∼70 MT/yr and ∼2.5 MT/yr for the anthropogenic system when the load decreased to ∼25 MT/yr. These numbers highlight the fact that due to the increase in density of human-dug canals sediment trapping on the delta plain check details has become a significant part of the present sediment budget of the delta (i.e., >10%). In the same time, these numbers suggest that the main impact of selleck screening library the increasing fluvial sediment deficit would be expected at the coast. If we assume that sediments that enter the interior of the delta from the main distributaries, either as overbank flows or via the narrow and shallow secondary canal network, do not escape back into the main distributaries, the sediment trapped in the interior of the delta can be estimated. This tenet is a reasonable one if we take into account almost all branches of the canal network end in or cross lakes that act as sediment traps. Making the supplementary
assumption that most, if not all, of this sediment feeds the internal fluvial delta rather than the marine delta, because canal selleck antibody inhibitor density is insignificant in the latter, we estimate the average sediment flux changed from 0.07 in natural conditions to 0.09–0.12 g/cm2 today when distributed uniformly across for an area the entire internal delta plain (∼2800 km2
or ∼2000 km2 without polders). The figures would be somewhat smaller when consider the losses to areas of the marine delta plain that do have some canals. However, these numbers ignore organic sedimentation that is expected to be significant in the internal delta. The flux estimates above translate into sedimentation rates of 0.5–0.8 mm/yr if we use a dry density of 1.5 g/cm3 for water saturated mixed sand and mud with 40% porosity (Giosan et al., 2012). In natural conditions, most of the internal delta plain was submerged with the exception of the levees of major and minor distributaries suggesting a sediment starved environment (Antipa, 1915). In anthropogenic conditions, the situation is probably similar with sediments rather than being spread evenly across the delta, accumulating close to the secondary channel network or in lakes fed by this network.