g., Oosterberg and Bogdan, 2000). In the Mississippi delta, nutrient excess delivered via diversions to freshwater marshes have been blamed for their apparent

vulnerability to hurricanes (e.g., Kearney LBH589 et al., 2011). For successful schemes of channelization, a comprehensive adaptive management plan for water, sediment and nutrients would be needed to protect the ecological characteristics in addition of maintaining the physical appearance of the delta plain. If increases in the sediment trapped on the fluvial delta plain may aid to balance the effects of sea level rise, a similar approach for the external, marine delta plain would completely change the landscape of that region. Composed of fossilized sandy beach and barrier ridges that receive little new sand once encased on the delta plain, the marine delta would be transformed by channelization into an environment akin to the fluvial delta with lakes and marshes. In the absence of other solutions, such as hard protection dikes and short of abandonment, channelization could potentially raise the ground locally on these strandplains and barrier plains. Instead, with no new sediment input, the marine delta would

in time result in its partial drowning; sand ridge sets of higher relief will transform into barrier systems and thus, with water on both sides, become dynamic again rather than being fossilized on the delta plain. This will provide in turn some protection to the remaining selleck mainland delta coast because Doxacurium chloride dynamic barrier systems with sand sources nearby (i.e., the delta lobes themselves) are

free to adjust to dynamic sea level and wave conditions by overwash, foredune construction, and roll over. However, it is clear that the most vulnerable part of the Danube delta is the deltaic coastal fringe where most of sediment deficit is felt. In order to tackle erosion along the delta coast, a series of large scale diversion solutions have been proposed since the early 20th century (see e.g., compilation by Petrescu, 1957). However, the entire Danube currently debouches only about half the amount of sediment that Chilia distributary used to deliver annually to construct its lobe in pre-damming era! Our study suggests instead that small but dense diversions similar to the natural Chilia secondary channels, thus another type of channelization mimicking natural processes, may minimize erosion in the nearshore. Hard structures such as breakwaters and groins that curtail offshore and alongshore sediment loss may also provide some temporary, if imperfect, relief. However, waves along the coast of Danube delta are a very efficient and relentless sediment redistribution machine, and in the long run erosion will remain a problem. Erosion of moribund lobes, such as it appears to be the case with the current St. George lobe, can provide enough sand if it is abandoned. Reworking of the St.