Bangalore Metropolitan Environment

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Bangalore, is situated in the southeast of the South Indian state of Karnataka. It is positioned at 12.97° N 77.56° E and covers an area of 2,190 km2 (1,360 mi2) A landlocked city, Bangalore is located in the heart of the Mysore Plateau (a region of the larger Deccan Plateau) at an average elevation of 920 m (3,000 feet). Bangalore district borders with Kolar in the northeast, Tumkur in the northwest, Mandya in the southeast and Mysore and Tamil Nadu in the south.

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[edit] Topology

The slopes of the Nandi Hills, located 60 km north of Bangalore.
The slopes of the Nandi Hills, located 60 km north of Bangalore.

Bangalore has two unique topological terrains — North Bangalore taluk and the South Bangalore taluk. The North Bangalore taluk is a relatively more level plateau and lies between an average of 839 to 962 meters above sea level. The middle of the taluk has a prominent ridge running NNE-SSW. The highest point in the city, Doddabettahalli, (962m) is on this ridge. There are gentle slopes and valleys on either side of this ridge. The low-lying area is marked by a series of water tanks varying in size from a small pond to those of considerable extent, but all fairly shallow.

The South Bangalore taluk has an uneven landscape with intermingling hills and valleys. The southern and western portions of the city consist of a topology of granite and gneissic masses. The eastern portion is a plane, with rare minor undulations.

There are no major rivers flowing through the city. However, rivers Arkavathi and Kaveri merge within the proximity of Nandi Hills, which lie 60 km north of Bangalore. River Vrishabhavati, a tributary of Arkavathi, flows for a small stretch in the Bangalore North taluk and carries a bulk of the city's sewerage. The city has a handful of freshwater lakes and water tanks such as Madivala tank, Hebbal tank, Ulsoor lake and Sankey tank. Groundwater occurs in silty to sandy layers of alluvial sediments and jointed quartzite.

The rock types prevalent in the district belong to the Saugar, Charnokite and Peninsular Gneissic Complex (PGC) groups. The PGC is the dominant group of rocks and covers two-thirds of the area and includes granites, gneissis and migmatites. The soils in Bangalore vary from red laterite to clayey soils.

[edit] Climate

Rainfall and temperature
Rainfall and temperature

Due to its elevation, Bangalore enjoys a pleasant and equable climate throughout the year. The highest temperature recorded was 38.9°C (102.0°F) on May 22, 1935 and the lowest was 7.8°C (46.06°F) in 1884. Winter temperatures rarely drop below 12°C (54°F) and summer temperatures seldom exceed 38°C (100°)[1][2]

Bangalore receives about 900 mm of rain annually, the wettest months being August, September, October and in that order. The summer heat is moderated by fairly frequent thunderstorms and occasional squalls causing power outages and local flooding. The heaviest rainfall recorded in a 24 hour period was 179.7 mm recorded on October 1, 1997.

Most of the rainfall occurs during late afternoon/evening or night and rain before noon is infrequent. October of 2005 was recorded as one of the wettest months in Bangalore with heavy rains causing severe flooding in some areas, and closure of a number of organisations for over a couple of days.[3]

[edit] Seismicity

Because it lies in the seismically stable region, Zone II (encompassing parts of Karnataka, Maharashtra, Kerala, Tamil Nadu and Andhra Pradesh), Bangalore has been untouched by major seismic events. Only mild tremours have been recorded in the city.

[edit] Land Use

Component PIU "ideal" Index Average Score
Air Quality 395 180
Water Quality 130 121
Land 40 37
Terrestrial ecosystem 150 143
Aquatic ecosystem 15 12.5
Socio-economic
(traffic, quality of life, etc.)
270 49.5
Total 1000 542
Table 1: Adapted from Table 17 of "Environment Impact Analysis" (2003) conducted by Bangalore Mass Rapid Transport Limited (BMRTL)

According to data contained in the Bangalore Mahanagara Palike Master Plan, 40.4% of the land in the city is used for residential purposes. Transport uses 24.3% of the land, while land used for industrial, and commercial purposes comprise 6.9% and 2.7% respectively. As the city of Bangalore expands, the BMP expects the percentage of land used for industrial purposes to decrease, while it expects the percentages of land used for residential, commercial and public and semi-public purposes to increase.

[edit] General Metropolitan Environment

A random sampling study of the Air Quality Index (AQI) of twenty stations within the city indicated scores that ranged from 76-314, suggesting heavy to severe air pollution around areas of traffic concentration. Major pollutants contributing to Bangalore's high AQI score include Nitrogen Oxide, Suspended Particulate Matter (SPM) and Carbon Monoxide.

The Bangalore metropolitan area, referred to as the Garden City of India has an abundance of fauna and flora. The city has two nationally renowned bontanical gardens — Cubbon Park and Lal Bagh. A majority of the trees in the city are big to medium canopy trees with girths above 40 cm. Coconut trees form a large minority of the tree population in the city.

In 2003, the Battelle Environmental Evaluation System (BEES) index used to evaluate environmental components was used to rate Bangalore's physical, biological and socioeconomic parameters. The results are summarized in Table 1.

[edit] See also

[edit] References