Mekong dykes & canals

[huy.duong@ctsu.ox.ac.uk]

Dear friends,

There is a political dimension too. Wouldn't it be a waste for Vietnam 
to build thousands of km of dykes & canals and in 10 years time there are so 
many dams on the Mekong that it will never flood? We must never forget
this dimension.

Floods occur because water can't flow away fast enough. Dykes can slow
down this flow because they restrict the flow to a channel whose bed
is continually raised. Dredging and digging more canals would give the water 
more ways to flow out to sea. Controlled (by natural topology or with the aid of
strategically built dykes) flooding of strategically selected areas,
perhaps in rotation, can make the flood more predictable and therefore less 
damaging, ensure a supply of silt to where it is useful and keep
critical areas unflooded. This is what the coffee table New Scientist
recommended.

Huy