The India Zone

Bangalore is situated in the southeast of the South Indian state of Karnataka. It is located in the heart of the Mysore Plateau (a region of the larger Precambrian Deccan Plateau) at an average elevation of 920 m (3,018 feet). It is positioned at 12.97° N 77.56° E and covers an area of 696.17 km² (269 mi²). Bangalore District borders with Kolar District in the northeast, Tumkur District in the northwest, Mandya District in the southwest, Chamarajanagar District in the south and the neighbouring state of Tamil Nadu in the southeast. The Bangalore Urban district is divided into three taluks: Bangalore North, Bangalore South and Anekal. The Bangalore North taluk is a relatively more level plateau, while the Bangalore South taluk has an uneven landscape with intermingling hills and valleys.

The topology of Bangalore is flat except for a central ridge running NNE-SSW. The highest point is Doddabettahalli, which is 962 m (3,156 ft) and lies on this ridge. No major rivers run through the city, though the Arkavathi and South Pennar cross paths at the Nandi Hills, 60 km (37 mi) to the north. River Vrishabhavathi, a minor tributary of Arkavathi, arises within the city at Basavanagudi and flows through the city. Together, rivers Arkavathi and Vrishabhavathi carry much of Bangalore's sewage. A sewerage system, constructed in 1922, covers 215 km² (133 mi²) of the city and connects with five sewage treatment centers located in the periphery of Bangalore.

In the 16th century, Kempe Gowda I constructed many lakes to meet the town's water requirements. The Kempabuddhi Kere, since overrun by modern development, was prominent. Later in the 20th century, the Nandi Hills waterworks, commissioned by Sir Mirza Ismail (Dewan of Mysore, 1926–41 CE), provided adequate water supply to the growing city. Bangalore currently relies heavily on water reservoirs from the Kaveri basin and on Vrishabhavathi and Arkavathi water treatment plants to meet the water needs of its population of six million. Bangalore receives 800 million litres (211 million US gallons) of water a day, more than any other Indian city. However, water shortages, especially during summer, are commonplace. A random sampling study of the Air Quality Index (AQI) of twenty stations within the city indicated scores that ranged from 76 to 314, suggesting heavy to severe air pollution around areas of traffic concentration.[22] For purposes of comparison, India's metropolitan cities Ahmedabad, Delhi and Kolkata were classified as having heavy pollution, while Bangalore and Mumbai were categorised as having moderate pollution.

The Agara Lake, at sunset. Bangalore has a large number of lakes — of these Sankey lake, Ulsoor lake and Yediyur lake are the most prominent.Bangalore has a handful of freshwater lakes and water tanks, the largest of which are Madivala tank, Hebbal lake, Ulsoor lake and Sankey Tank. Groundwater occurs in silty to sandy layers of the alluvial sediments. Bangalore receives adequate rainfall from the Northeast Monsoon as well as the Southwest Monsoon. The Peninsular Gneissic Complex (PGC) is the most dominant rock unit in the area and includes granites, gneisses and migmatites, while the soils of Bangalore consist of red laterite and red, fine loamy to clayey soils. Vegetation in the city is primarily in the form of large deciduous canopy and minority coconut trees. Bangalore has not been affected by major seismic activity due to it being located in a seismically stable zone (Zone II). Only mild tremors have been recorded in the city.

Because of its elevation, Bangalore enjoys a pleasant and equable climate throughout the year. The highest temperature recorded is 41°C and the lowest is 7.8°C Winter temperatures rarely drop below 12°C (54°F), and summer temperatures seldom exceed 36–37°C (100°F). Monsoons commence sometime around mid April, when the depression gathers around the Arabian Sea. The wettest months are August, September and October, in that order. The summer heat is moderated by fairly frequent thunderstorms, and occasional squalls cause power outages and local flooding. Most of the rainfall occurs during in late afternoon, evening or night, and rain before noon is infrequent. The heaviest rainfall recorded in a 24-hour period is 180 mm (7 in) recorded on 1 October 1997. Bangalore, receives both incoming and outgoing monsoons because of its geographic location.