Geography of Chennai

Source: Wikipedia, the free encyclopedia.

Chennai is situated on a flat coastal plain, as can be seen in this Landsat 7 map.

Chennai is located at 13°02′N 80°10′E / 13.04°N 80.17°E / 13.04; 80.17 on the southeast coast of India and in the northeast corner of Tamil Nadu. It is located on a flat coastal plain known as the Eastern Coastal Plains. The city has an average elevation of 6 metres (20 ft), its highest point being 60 m (200 ft). Chennai is 2,184 kilometres (1,357 miles) south of Delhi, 1,337 kilometres (831 miles) southeast of Mumbai, and 1,679 kilometers (1,043 miles) southwest of Kolkata by road.

Chennai and surrounding towns

Geology

The

West Mambalam, Anna Nagar, Perambur and Virugambakkam. The geology of the Chennai city and its surroundings derived from the map of the Geological Survey of India is shown in figure.[3]

Chennai's Geology and its surroundings after GSI
Geology of Chennai and surroundings (after GSI)[4]

Climate

Chennai has a dry-summer

tropical wet and dry climate which is designated As under the Köppen climate classification.[5][6] Chennai lies on the thermal equator and is also coastal, which prevents extreme variation in seasonal temperature. For most of the year, the weather is hot and humid. The hottest part of the year is late May and early June, known locally as Agni Nakshatram ("fiery star") or as Kathiri Veyyil, with maximum temperatures around 38–42 °C (100–108 °F). The highest recorded temperature was 45 °C (113 °F) on 31 May 2003.[7] The coldest time of the year is in December–January, with average temperature of 19–25 °C (66–77 °F) and the lowest recorded temperature of 13.9 °C (57.0 °F) on 11 December 1895 and 29 January 1905.[8]

The average annual

rainfall is about 1,400 mm (55 in). The city gets most of its seasonal rainfall from the north-east monsoon winds, from mid-September to mid-December while smaller amounts also come from the south-west monsoon winds from mid-June to mid-September. Cyclones in the Bay of Bengal sometimes hit the city. Highest annual rainfall recorded is 2,570 mm in 2005.[9]
The most prevailing winds in Chennai is the Southwesterly between the end of May to end of September and the Northeasterly during the rest of the year.

Climate data for Chennai (Nungambakkam; rainfall from Chennai Airport) 1991–2020, extremes 1901–2012
Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year
Record high °C (°F) 34.4
(93.9)
36.7
(98.1)
40.6
(105.1)
42.8
(109.0)
45.0
(113.0)
43.3
(109.9)
41.1
(106.0)
40.0
(104.0)
38.9
(102.0)
39.4
(102.9)
35.4
(95.7)
33.0
(91.4)
45.0
(113.0)
Mean daily maximum °C (°F) 29.3
(84.7)
30.9
(87.6)
32.9
(91.2)
34.5
(94.1)
37.1
(98.8)
37.0
(98.6)
35.3
(95.5)
34.7
(94.5)
34.2
(93.6)
32.1
(89.8)
29.9
(85.8)
28.9
(84.0)
33.1
(91.6)
Daily mean °C (°F) 25.4
(77.7)
26.7
(80.1)
28.7
(83.7)
31.0
(87.8)
33.0
(91.4)
32.3
(90.1)
31.0
(87.8)
30.3
(86.5)
29.8
(85.6)
28.5
(83.3)
26.7
(80.1)
25.6
(78.1)
29.1
(84.4)
Mean daily minimum °C (°F) 21.2
(70.2)
22.2
(72.0)
24.2
(75.6)
26.6
(79.9)
28.0
(82.4)
27.5
(81.5)
26.4
(79.5)
25.9
(78.6)
25.6
(78.1)
24.6
(76.3)
23.1
(73.6)
21.9
(71.4)
24.8
(76.6)
Record low °C (°F) 13.9
(57.0)
15.0
(59.0)
16.7
(62.1)
20.0
(68.0)
21.1
(70.0)
20.6
(69.1)
21.0
(69.8)
20.5
(68.9)
20.6
(69.1)
16.7
(62.1)
15.0
(59.0)
13.9
(57.0)
13.9
(57.0)
Average rainfall mm (inches) 20.0
(0.79)
4.7
(0.19)
3.4
(0.13)
17.5
(0.69)
49.7
(1.96)
75.4
(2.97)
113.1
(4.45)
141.4
(5.57)
143.9
(5.67)
278.3
(10.96)
377.3
(14.85)
183.7
(7.23)
1,408.4
(55.45)
Average rainy days 1.4 0.6 0.2 1.0 1.8 4.5 6.7 8.8 7.4 10.6 11.5 5.7 60.2
Average
relative humidity (%) (at 17:30 IST
)
67 66 67 70 68 63 65 66 71 76 76 71 69
Mean monthly sunshine hours 232.5 240.1 291.4 294.0 300.7 234.0 142.6 189.1 195.0 257.3 261.0 210.8 2,848.5
Mean daily sunshine hours 7.5 8.5 9.4 9.8 9.7 7.8 4.6 6.1 6.5 8.3 8.7 6.8 7.8
Average ultraviolet index 7 7 7 8 8 8 8 7 7 6 7 7 7
Source 1: India Meteorological Department[10][11][12][13]
Source 2: Japan Meteorological Agency[14] Weather Atlas[15]


Water bodies

Two rivers meander through Chennai, the

brackish. A study by the Department of Geology, Anna University, based on a city map of 1893, has revealed that there were nearly 60 large waterbodies in the core of then Madras.[17] The study traced the shrinking and vanished waterbodies through a series of city maps.[18]

Historically, Chennai has faced a problem of water supply shortages as no big river flows through it with a resulting over-reliance on annual

Krishna river in Andhra Pradesh have eased water supply shortages. The city is also constructing sea water desalination
plants to further ease water supply shortages.

Layout

For administrative purposes Chennai is divided into five

talukas
; namely Egmore-Nungambakam, Fort Tondiarpet, Mambalam-Guindy, Mylapore-Triplicane and Perambur-Purasawalkkam.

The Chennai Metropolitan area consists of five districts namely Chennai city and the districts of

Thiruvallur and Ranipet. The city area covers an area of 476 km2 (184 sq mi).[21]
The metropolitan area covers 1,177 km2 (454 sq mi). The city is divided on the basis of composition into four major parts: North, Central, South and West.

North Chennai is primarily an industrial area. Central Chennai is the commercial heart of the city and the downtown area. South Chennai and West Chennai, previously predominantly residential areas are fast turning into commercial areas, hosting a large number of

Sriperumbdur, Koyambedu and Ambattur
.

The

to the west.

References

  1. ^ "Practices and Practitioners – Chennai". Rainwater harvesting. Retrieved 5 August 2005.
  2. ^ "A ready reckoner on rainwater harvesting". Govt. of Tamil Nadu / New Indian Express. Archived from the original on 23 June 2005. Retrieved 5 August 2005.
  3. ^ "Suganthi". revistas.unal.edu.co. Retrieved 30 July 2020.
  4. ^ "Suganthi". revistas.unal.edu.co. Retrieved 30 July 2020.
  5. ^ "About Chennai" (PDF). Chennai Metropolitan Development Authority. p. 28. Retrieved 25 February 2024.
  6. .
  7. ^ "Climatology tables:Extremes till 2012" (PDF). India Meteorological Department. Archived (PDF) from the original on 5 February 2020. Retrieved 29 May 2023.
  8. ^ "Climatology tables:Normal 1981-2010" (PDF). India Meteorological Department. p. 279. Archived (PDF) from the original on 20 June 2023. Retrieved 29 May 2023.
  9. ^ T. Ramakrishnan (3 January 2006). "Entering 2006, city's reservoirs filled to the brim". The Hindu. Archived from the original on 28 February 2007. Retrieved 4 May 2007.
  10. ^ "Station: Chennai (Nungambakkam) Climatological Table 1981–2010" (PDF). Climatological Normals 1981–2010. India Meteorological Department. January 2015. pp. 185–186. Archived from the original (PDF) on 5 February 2020. Retrieved 2 March 2020.
  11. ^ "Extremes of Temperature & Rainfall for Indian Stations (Up to 2012)" (PDF). India Meteorological Department. December 2016. p. M192. Archived from the original (PDF) on 5 February 2020. Retrieved 2 March 2020.
  12. ^ "Table 3 Monthly mean duration of Sun Shine (hours) at different locations in India" (PDF). Daily Normals of Global & Diffuse Radiation (1971–2000). India Meteorological Department. December 2016. p. M-3. Archived from the original (PDF) on 5 February 2020. Retrieved 2 March 2020.
  13. ^ "Chennai Climatological Table 1981–2010". India Meteorological Department. Retrieved 2 March 2020.
  14. ^ "Normals Data". Japan Meteorological Agency. Retrieved 11 May 2020.
  15. ^ "Climate and monthly weather forecast Chennai, India". Weather Atlas. Retrieved 13 June 2022.
  16. ^ "Chennai". lifeinchennai.com. Retrieved 27 July 2009.
  17. ISSN 0971-751X
    . Retrieved 30 July 2020.
  18. . Retrieved 30 July 2020.
  19. ^ "Chennai Water Supply". Management of water supply during acute water scarcity in 2003 & 2004. Chennai Metropolitan Water Supply and Sewage Board (CMWSSB). Archived from the original on 12 August 2007. Retrieved 16 March 2007.
  20. ^ "Bangalore team visits RWH structures in city", The Hindu, 3 August 2007, accessed 11 August 2007
  21. ^ "General statistics". Corporation of Chennai. Retrieved 4 August 2005.