BharatSangraha

Chola Nadu · Eastern Coastal Plains

Terrain and eco-zones

Tropical and, unusually for India, dependent on the retreating monsoon rather than the advancing one. Most of the delta's 1,000–1,300 mm falls between October and December from the northeast monsoon, which arrives as depressions and cyclones off the Bay rather than as a broad front. That single fact organises the year — the delta sows to the Mettur reservoir's release date in June and harvests against the October storms.

Landforms

Old delta — the mature, canal-irrigated fan below the Grand Anicut, gently graded and almost featurelessNew delta — the eastern and southern extension brought under command in the twentieth century, sandier and more salineCoastal sand ridges and back-swamps, with salt pans behind them at VedaranyamMuthupet mangrove lagoon at the delta's southern lip, the largest mangrove tract on this coastPoint Calimere (Kodiakkarai) — the blunt cape where the coastline turns west into the Palk Strait

Rivers and waters

Cauvery — the trunk, split at the Grand Anicut into the Cauvery proper and the KollidamKollidam (Coleroon) — the flood-carrying northern arm, and the region's northern boundaryVennar, Vettar, Arasalar, Mudikondan, Koraiyar, Harichandranadhi — the working distributariesUppanar and the coastal backwaters behind NagapattinamVeeranam and Kallanai canal systems, plus several thousand tanks that buffer the delta between releases

Through the year

SeasonMonthsTypicalWhat it is like
KuruvaiJune–September28–38 °CThe short first paddy crop, sown when Mettur is opened and harvested before the storms. It exists only where irrigation is assured, which is why the kuruvai acreage is the delta's own measure of a good year.
SambaAugust–January24–34 °CThe long main crop, timed to take the northeast monsoon in the field. Most of the delta's traditional long-duration varieties are samba varieties, and most of its festivals sit inside this window.
Thaladi and the storm seasonOctober–December23–32 °CLate-planted paddy, and the months when cyclones make landfall. Gaja in November 2018 flattened an estimated eight lakh coconut palms across the delta and is still the local benchmark for a bad year.
KodaiMarch–June30–41 °CThe dry gap. Fields are fallow or under pulses, tanks are desilted under the customary kudimaramathu labour, and temple car festivals fall here because the ground is hard enough to pull on.

Best time to visitDecember to March. The Tyagaraja aradhana at Thiruvaiyaru falls in January, Natyanjali at Chidambaram on Maha Shivaratri in February or March, and the fields are green for the samba harvest. Avoid the cyclone window from late October to early December unless the point is to watch the delta work.

The climate, landforms, rivers and seasons of Chola Nadu, and the best time of year to visit. (4)