06-bioresourcesstatu.. - M. S. Swaminathan Research Foundation

I. Introduction
Vembanad Lake
The State of Kerala comprises of the narrow
southern most strip of the humid western ghats
and is bound by South Kanara on the north and on
the east, in descending order by western
Karnataka, Nilgiris, Coimbatore, Madurai,
Ramanathapuram and in the extreme south by
Tirunelveli and Kanyakumari districts of Tamil
Nadu. The eastern and western boundaries are
demarcated by natural features: all along the west
stretches the Arabian sea; and on the east the
western ghats, three thousand to eight thousand
feet (900 - 2450 m) high, separate the area from
the adjoining states of Karnataka and Tamilnadu.
The ghats are thickly wooded in parts with
mountain scenery of unrivalled beauty. Kerala
exhibits considerable diversity in terrain but is
broadly divisible into three well-defined zones: the
hills, the plains and the seaboard. Owing to the
mountainous nature of the state in parts and the
heavy rainfall it receives, streams are numerous.
In the Malabar region the principal rivers are the
Bhavani, Kabbani and the Rampur, tributaries of
the Cauvery, which flows eastward into
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Vembanad Lake
- S.K.Chakraborty and S. Ayyappan
Karnataka. But majority of the streams rise on the
western face of the watershed, the Periyar,
Chalakudi, Minachil, Pambiyar and Kodayar being
the more important of these. Most of them have
very winding courses and they all discharge
themselves into the backwaters or estuarine
lagoons - a chain of which extends almost along
the entire coast, separated from the sea hy a bar
of sand or silt. A number of these rivers have the
dams constructed for hydroelectric and irrigation
purposes.
The climate of Kerala all along the coast is
equable and damp with the temperature seldom
rising above 32'C and fall below 20'C. In the hills,
the temperature varies with altitude. Rainfall is
very heavy, the greatest being under the influence
of southwest monsoon between May and
September. The State however, receives the benefit
of northeast monsoon as well. The mean annual
rainfall is around 250 cm for the state. The mean
relative humidity is around 70% and it may be 90%
at the highest. The abundant rainfall and
excessive humidity are responsible for effects on
climate and vegetation. The tropical rain forest is
observed at many of the places.