Wednesday 9 October 2013

AP Coast face threat due sea level rise, Vishakapatnam coast faces sumergence: ISRO study

U Sudhakar Reddy

State coast has been identified as most vulnerable to the impacts of 
the sea level rise with 43 per cent of the coast is under very high-risk and 35 per cent 
more is under high-risk category according to Indian Space Research Organisation’s study 
on coastal vulnerability assessment.
Coastal vulnerability Index in Andhra Pradesh has been very high ranging from 15 to 57 in 
certain areas. Vishakapatnam city has been identified as one of the coastal hotspots in 
the country facing a threat of coastline submergence.  Sea-level rise is likely to 
intensify the storm surges besides accelerating shoreline erosion, seawater intrusion and 
damage to coastal structures.

The scientists observed that the rise in sea-level will have serious impact on the urban 
region of Vishakapatnam as number of industries, the airport and other establishments 
besides some residential colonies are within 3 to 4 metres above sea-level at present.
The report revealed that the rising sea-levels, storm surges, tsunamis would have 
amplification effect over the city area since a part of the city area, especially the 
western tidal swamp is like a filled-in bay lying in between two rocky headlands. “In the 
event of 0.6 m rise in sea level, the area between the present low-tide level and the 
future low-tide level which is about 361 ha including 50 ha of mangrove swamp and 271 ha 
of industrial area would be submerged under the sea.the future high tide would shift by 
another 0.6 m landward marked by the present 2.1m contour. Therefore, an additional area 
of about 348 ha between the 1.5 m and 2.1 m contours would become a part of the future 
intertidal area. This area which is at present occupied by industrial establishments (152 
ha), residential (6 ha), scrubland (70 ha), etc., would be affected by regular tidal 
changes. The study highlights the impact of the predicted sea-level rise in Visakhapatnam 
city area which is a densely populated and highly industrialized part of the AP coast.
Marine Biologist Dr Duggaraju Srinivasa Rao said,”Chinna Gollapalem in Krishna district 
is already witnessing erosion and it will be soon wiped out. In Krishna and West Godavari 
mangrove has been seriously affected due shrimp culture. There is no strength for 
mangroves as there is no fresh water coming in except during flooding situation. The ice 
factories along the coast have sucked up the ground water to a large extent. Salt water 
has intruded inside. Along the Vishakapatnam coastline erosion, gas drilling and dredging 
have resulted in huge damage.”
ISRO report was released by Ministry of Forest and Environment revealed,”the 1030 km 
coastal regions in AP are highly vulnerable and the recent history of shoreline behavior 
in terms of erosion and accretion indicated that about 31 per cent experienced a very 
high degree of erosion,”
In Vishakapatnam although several smaller hillocks dot the city area a large tract 
low-lying swampy tidally submergible backwater area is located to the west of the city. 
This swampy area which occupied about 14 square kilometer three decades ago has reduced 
to a mere 1.37 square kilometre 2003 by reclamation for industrial activity in this port 
city. The elevation of the airport built in the western side of the swampy area is just 
about 2 to 3 m above sea-level. Maps comparison revealed some parts of the 10-kmlong 
beach front of the city were subjected to erosion.  Insect attack and fungus has also 
resulted in depletion of mangroves apart from aquaculture and agriculture.