Egypt's fertile Nile Delta is shrinking
Prior to the building of the Aswan High Dam in the 1960s, more than 120
million tonnes of silt washed down the Nile each year and accumulated in
its delta. Without this annual silt flow to replenish it, the Nile
Delta is shrinking – in some places the coastline is receding by as much
as 175 metres a year.
The Egyptian government has attempted to slow the sea’s advance by
building a series of breakwaters and earthen dykes along the northern
coast and its waterways. Piles of concrete blocks help reduce coastal
erosion, but without new sedimentation, the delta land has compacted and
thousands of hectares now lie at sea level...
El-Rayis warns that as the delta substratum becomes more porous,
seawater has begun to infiltrate the Nile Delta aquifer, a vital source
of underground water spread over 2.5 million hectares.
Saltwater has always been a threat to coastal agricultural land, but
salinity was traditionally kept in check by a steady flow of freshwater
covering the soil and flushing out the salt. As Egypt’s population has
expanded, upstream demand on water has increased, reducing the amount of
Nile water that reaches the Delta. What does trickle in these days is
choked with sewage and industrial toxins.
Labels: Egypt, Environment