1. Introduction
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vary significantly consisting of sandy beaches, calcareous reefs, bays, tidal
inlets, head lands and mangrove marshes.
In the Coastal stretch between Chennai and Mahabalipuram beaches on
the onshore side are moderate to steep and hence the backshore of beaches
is elevated much above the mean sea level. The beaches are formed by
the interception of net northerly longshore sand transport. The classical
example is the formation of marina beach due to the existence of breakwaters of Chennai harbour. The longshore sédiment transport along this
stretch has also resulted in closure of river mouths. Between the stretch
of the coast from Cuddalore and Nagapattinam the backshore areas hâve
very low relief and fringed with several tidal inlets. For example, Rivers
Gadilum and Vellar in their delta régions form several tidal inlets between
Cuddalore and Poombuhar before reaching the Bay of Bengal. Similarly
the river Cauvary in the delta région between Poombuhar and Nagapatinam branches off into number of distributaries forming several tidal inlets.
From the Point Calimere to Tuticorin beaches are wide and hâve mild slope.
The sea coast in this région is exposed to wave action from the Palk Bay
and the Gulf of Mannar. The Palk bay is enclosed on three sides by land
and has a narrow shallow opening (~60 km) on the north to the Bay of
Bengal. The water depth in the Palk bay is less than 10 m and the bay area
is nearly 150 km2. The fetch length available for wave génération in the Palk
bay is small (about 10 km in the North-South direction and 15 km in the
East-West direction), and consequently the wave heights observed along
its coast are in general small throughout the year. Hence, the wave action
along the coast between the Point Calimere and Ramesvaram Island will
not be significant. Similarly the coast between Ramesvaram and Tuticorin
bordering the northern part of the Gulf of Mannar, which lies between
Sri Lanka and India, is not subjected to significant wave action. In the
Coastal région around Tuticorin, and between Thiruchendur and Kannyakumari the offshore reefs exist nearly for about 500 m from the coast and
function like a discontinuous submerged breakwater and protect the coast
from the impacts of waves.
On the western side of Tamil Nadu, the coastline facing the Arabian Sea
extends from Kannyakumari to Eraiyummanthurai. This coast is steep and
has many rocky outcrops. The coast expériences high swell waves during
the south west monsoon and these waves breaking near the coast lead to
heavy érosion of beaches, and after monsoon accretion takes place and the
beaches recover back. Thus, the geomorphology of the coast varies from
north to Southern tip of the State.
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vary significantly consisting of sandy beaches, calcareous reefs, bays, tidal
inlets, head lands and mangrove marshes.
In the Coastal stretch between Chennai and Mahabalipuram beaches on
the onshore side are moderate to steep and hence the backshore of beaches
is elevated much above the mean sea level. The beaches are formed by
the interception of net northerly longshore sand transport. The classical
example is the formation of marina beach due to the existence of breakwaters of Chennai harbour. The longshore sédiment transport along this
stretch has also resulted in closure of river mouths. Between the stretch
of the coast from Cuddalore and Nagapattinam the backshore areas hâve
very low relief and fringed with several tidal inlets. For example, Rivers
Gadilum and Vellar in their delta régions form several tidal inlets between
Cuddalore and Poombuhar before reaching the Bay of Bengal. Similarly
the river Cauvary in the delta région between Poombuhar and Nagapatinam branches off into number of distributaries forming several tidal inlets.
From the Point Calimere to Tuticorin beaches are wide and hâve mild slope.
The sea coast in this région is exposed to wave action from the Palk Bay
and the Gulf of Mannar. The Palk bay is enclosed on three sides by land
and has a narrow shallow opening (~60 km) on the north to the Bay of
Bengal. The water depth in the Palk bay is less than 10 m and the bay area
is nearly 150 km2. The fetch length available for wave génération in the Palk
bay is small (about 10 km in the North-South direction and 15 km in the
East-West direction), and consequently the wave heights observed along
its coast are in general small throughout the year. Hence, the wave action
along the coast between the Point Calimere and Ramesvaram Island will
not be significant. Similarly the coast between Ramesvaram and Tuticorin
bordering the northern part of the Gulf of Mannar, which lies between
Sri Lanka and India, is not subjected to significant wave action. In the
Coastal région around Tuticorin, and between Thiruchendur and Kannyakumari the offshore reefs exist nearly for about 500 m from the coast and
function like a discontinuous submerged breakwater and protect the coast
from the impacts of waves.
On the western side of Tamil Nadu, the coastline facing the Arabian Sea
extends from Kannyakumari to Eraiyummanthurai. This coast is steep and
has many rocky outcrops. The coast expériences high swell waves during
the south west monsoon and these waves breaking near the coast lead to
heavy érosion of beaches, and after monsoon accretion takes place and the
beaches recover back. Thus, the geomorphology of the coast varies from
north to Southern tip of the State.