Nice Article. Pretty revealing.



Regards,

SAMEER BANERJEE



_____

From: andamanicobar@...
[mailto:andamanicobar@...] On Behalf Of Naveen Namboodiri
Sent: Thursday, October 09, 2008 1:44 AM
To: andamanicobar@...
Subject: [andamanicobar] Coastal Soil Erosion in Orissa - who will
bellthecat???




Dear all,

How easy and convenient to blame it all on the tsunami... if tsunami was to
blame, the coasts of tamil nadu and the ANI should have been the first to
have faced this phenomenon.

Well if tsunami is not working, then the second option... blame it on
climate change...

Do people know what is the source of sand to a beach? A major portion, if
not all of the sand found on the beaches are of terrigenous origin (ie from
terrestrial sources). This sand gets tranported by rivers to the sea and
later by nearshore currents that carry and deposit sand on to the beaches.
Every beach in the world has a sand budget of its own... it is a dynamic
balance between erosion and accretion of sand. Storms and cyclones lead to
major erosion of beaches and more often,over time, beaches do bounce back to
their original form in a matter of few years. But provided, there is
constant supply of sand.

The beaches of India, especially on the east coast of India (and very much
so in Orissa) has a sand budget that depends greatly on a long shore current
(that predominantly moves south to north) transporting tonnes of sediment
and gradually depositing them forming beaches.

Any man made structure on beaches (seawalls, groynes, ports, breakwaters,
harbours etc) blocks and disrupts this sand transport, leading to an
impoverished supply of sand to beaches lying to the north of these
structures. Even a dam constructed far upstream has major implications on
shoreline changes. While erosion of beaches may not be prominent immediately
after a new construction, it certainly becomes quite obvious in a few years
time, depending on the beaches and the extent of waves they are exposed to.
So instead of spending 15 crores and looking at the seabed for answers,
perhaps looking a bit down south for some recent major construction on the
coast and to check if this has something to do with the disappearing beaches
could be more enlightening.

Further, an economic valuation of the costs comparing the profits generated
by ports or similar structures vs the economics for protecting the coasts
over a long term could be quite interestting. Or maybe no one wants to bell
the cat.

Naveen.

Dr. Naveen Namboodiri,
Post Doctoral Fellow
Coastal and Marine Programme (CMP)
Ashoka Trust for Research in Ecology and the Environment (ATREE)
No. 659, 5th 'A' Main Road, Hebbal
Bangalore, 560 024
www.atree.org/cmp.html
naveen_cas@yahoo. <mailto:naveen_cas%40yahoo.co.in> co.in
naveen.namboodiri@ <mailto:naveen.namboodiri%40atree.org> atree.org

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