Landsat mosaic (A) shows urban expansion (yellow);
development of large sand dunes (pink); coastal erosion,
and salt pans. Map B shows topographic and georaphic
features of the Nile delta and major cities.
This is an abstract from:
Daniel Jean Stanley and Andrew G. Warne
Journal of Coastal Research Vol. 14, No. 3, pp. 794-825,
Summer 1998.
All deltas undergo alternating construction to
destruction phases due to fundamental changes in
the relative influence of sediment input from rivers
and redistribution by marine coastal processes.
During the past 7000 years world deltas, including
the Nile, have been in an overall construction
phase. However, the Nile delta has converted to a
destruction phase during the past 150 years,
triggered by water regulation which has disrupted
the balance among sediment influx, erosive effects
of coastal processes, and subsidence. This former
depocenter has been altered to the extent that it is no longer a functioning delta but, rather, a subsiding and
eroding coastal plain.
Symptoms of the destruction phase of the Nile delta include accelerated coastal erosion and
straightening of the shoreline, reduction in wetland size, increased landward incursion of saline groundwater,
and buildup of salt and pollutants to toxic levels in wetlands and delta plain. Without seasonal flushing by
floods, the former delta plain surface is now incapable of recycling and/or removing agricultural, municipal and
industrial wastes generated by Egypt’s rapidly expanding population. Moreover, the remaining capacity of the
system to regenerate itself will further diminish as water is diverted away from the delta for new irrigation and
municipal projects in the Egyptian desert, and water allocations to Egypt are decreased by upstream countries.
Re-establishing some level of natural hydrology is the only credible solution for attaining equilibrium
among sediment accretion on the delta plain to offset subsidence, progradation along the coast to offset
erosion, and sufficient water influx to flush and remove the high levels of salt and pollutants throughout the
system. However, increased Nile water and sediment discharge could begin to restore a functioning delta
system only if there is a substantial reduction in human impacts.