Tiruchirappalli - Geography and Climate

Geography and Climate

Tiruchirappalli is located at 10°48′18″N 78°41′08″E / 10.8050°N 78.6856°E / 10.8050; 78.6856. The average elevation is 88 metres (289 ft). It is located almost at the geographic centre of the state of Tamil Nadu. The topology of Tiruchirappalli is almost flat with a few isolated hillocks rising above the surface, the highest of which is the Rockfort. The city spread over an area of 146.7 square kilometres (56.6 sq mi) is situated on the plains between the Shevaroy Hills to the north and the Palni Hills to the south and south-west. The city is situated at the head of the Kaveri Delta, which commences 16 kilometres (9.9 mi) west of Tiruchirappalli where the Kaveri River branches into two streams forming the island of Srirangam.

The land immediately surrounding the Kaveri is made up of fertile alluvial soil deposited by the Kaveri and its tributary, the Kollidam. Further south, the surface is covered by poor-quality black soil. The alluvial soil is conducible for agriculture and crops such as ragi (finger millet) and cholam (maize) are cultivated. North-east of Tiruchirappalli runs a belt of cretaceous rock known as the "Trichinopoly Group". Layers of archaean rocks, granite and gneiss covered by a thin bed of conglomeratic laterite are found to the south-east of the city.

Densely-populated industrial and residential areas have recently emerged in the northern part of the city. Residential areas also cover the southern edge of the city. The city is completely surrounded by agricultural fields. The older part of the city, situated within the fort, is unplanned and congested while the adjoining newer sections are better executed. Many of the old houses in Srirangam were constructed according to the shilpa sastras, the canonical texts of Hindu temple architecture. A Local Planning Authority for Tiruchirappalli was created on 5 April 1974 as per the Tamil Nadu Town and Country Planning Act of 1971 with the District Collector of Tiruchirappalli as Chairman and the Assistant Director of Town and Country Planning as its member secretary. The city gets its drinking water supply from the Kaveri River and 1,470 bore wells linked to 60 service reservoirs in and around the city.

Tiruchirappalli is hot and dry for at least eight months of the year. The hottest months are from March to July during which the city experiences frequent dust storms. During this period, the days are extremely warm and dry while evenings are rendered cooler due to the cold winds that blow from the south-east. Tiruchirappalli experiences a moderate climate from August to October, tempered by heavy rain and thundershowers, and cool and balmy climate from November to February. Fog and dew are rare and occur only during the winter season.