Kaveri Delta Region: Impact of human interventions on this sensitive eco-system
The Kaveri delta region is characterized by a series of backwaters, low-lying marshy areas, mangroves and sand dunes and ridges. The eco-system is highly sensitive and stands witness to the interactions of land and sea since time immemorial.
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There are
elaborate traditional drainage systems - series of ponds, tanks, and a
network canals built over a century ago which have helped in flood control
as well as irrigation and water harvesting. These ponds and tanks are known
as Kulams and Eris respectively.
Over the years, the natural drainage channels have been encroached upon and man-made structures -settlements, roads, bridges, etc.etc. have been built. The reconstruction scenario has also seen similar encroachments which have blocked the natural drainage channels. The traditional water harvesting systems have also been gradually neglected and over the years have become dysfunctional -often dried up or over-run with weeds and silted heavily. |
The important
rivers include the Kaveri, the Ponnaiyar, the Palar, the Vaigai, and the
Tambraparni, all of which flow eastward from the inland hills. The Kaveri and
its tributaries are Tamil Nadu's most important sources of water and power.
The river has a braided and extensively irrigated deltaic region of about 4,000 square miles (10,360 square km). A dam called the Grand Anicut was built in the 2nd century at the point where the river divides. A second dam (1836-38) across the Kollidam, the river's northern and larger channel, saved the old system from silting and extended irrigation. The open roadsteads of Nagappattinam and Karikal are on the seaward side of the delta. The Kaveri region is known as the rice bowl of Tamil Nadu. |
The geomorphic characteristics of Kaveri river delta is such that it is difficult to meet the criteria laid out in technical guidelines regarding site elevation from sea as minimum 5 mtrs. 500 mtr. distance criteria also does not ensure safety as tsunami experience showed that at many places due to presence of backwaters houses in inland areas were worse affected than ones closer to sea. At this stage where many of the sites do not meet the defined criteria, it may be more prudent for technical guidelines to identify additional features that should be incorporated to enhance site safety.
Though lay out plans for each site has been prepared and formal approval procedure followed, planning norms about open spaces, community infrastructure, land use, etc. have not been incorporated except in few instances. Layout planning norms must be provided as guidelines and implemented. Site analysis and planning guidelines should also be brought out so that same can be followed.- Mid-term assessment of Shelter Reconstruction by UNDP, Hunnarshala, NCRC
The geomorphic characteristics of Kaveri river delta is such that it is difficult to meet the criteria laid out in technical guidelines regarding site elevation from sea as minimum 5 mtrs. 500 mtr. distance criteria also does not ensure safety as tsunami experience showed that at many places due to presence of backwaters houses in inland areas were worse affected than ones closer to sea. At this stage where many of the sites do not meet the defined criteria, it may be more prudent for technical guidelines to identify additional features that should be incorporated to enhance site safety.
Though lay out plans for each site has been prepared and formal approval procedure followed, planning norms about open spaces, community infrastructure, land use, etc. have not been incorporated except in few instances. Layout planning norms must be provided as guidelines and implemented. Site analysis and planning guidelines should also be brought out so that same can be followed.- Mid-term assessment of Shelter Reconstruction by UNDP, Hunnarshala, NCRC
Further readings :
1. Energy and Resources-India, Earth Trends, Country Profiles
2. Greenhouse gas emissions from India: A perspective; Subodh Sharma, Sumana Bhattacharya and Amit Garg; CURRENT 326 SCIENCE, VOL. 90, NO. 3, 10 FEBRUARY 2006
3. Sea level changes along the Indian coast: Observations and projections; A. S. Unnikrishnan1,*, K. Rupa Kumar2, Sharon E. Fernandes3, G. S. Michael1 and S. K. Patwardhan2; CURRENT 362 NT SCIENCE, VOL. 90, NO. 3, 10 FEBRUARY 2006