T.V. Ramachandra*, Bharath H. Aithal, Gouri Kulkarni, Vinay S

Energy & Wetlands Research Group, Centre for Ecological Sciences [CES],
Indian Institute of Science, Bangalore, Karnataka, 560 012, India,
Web URL: http://ces.iisc.ernet.in/energy; http://ces.iisc.ernet.in/foss,
*Corresponding author:cestvr@ces.iisc.ernet.in


Land use analysis using remote sensing data show that the spatial extent of  tree vegetation in Bangalore is  100.02 sq.km (14.08%).  Spatial extent of vegetation is minimum (less than 1 hectare) in wards such as Chickpete, Shivajinagara, Kempapura agrahara, Padarayanapura, while wards such as Varthur, Bellandur, Agaram have higher vegetation cover (> 300 hectares). The wards such as Hudi, Aramane nagara and Vasantha pura have higher vegetation density (spatial extent of area under vegetation to the geographical are of a ward) of more than 0.4, while Chickpete, Laggere, Hegganahalli, Hongasandra, Padarayanapura have lower density with less than 0.015. Bangalore has an average vegetation density of 0.14. Mapping of trees based on canopy delineation coupled with field data show that wards such as Vathuru, Bellanduru, Agaram, Aramane nagara have the trees greater than 40000 trees, while  Chickpete, Padarayanapura, Shivaji nagara, Kempapura Agrahara, Kushal nagara wards have trees less than 100 trees. Based on these, total number of trees in Bangalore is about 14,78,412 trees. Computation of trees per person show that Shivaji nagara, Dayananda nagara, Chickpete, Padarayanapura, Kempapura Agrahara wards have very less number of trees per person (< 0.002). This highlights that these wards have less than 1 tree for every 500 people. Compared to this, wards such as Bellanduru, Jakkuru, Varthuru, Agaram, Aramane nagara have trees more than one per person indicating the presence of one tree for every person. Intra city analysis show that major cities such as Gandhinagar, Bangalore, Ahmedabad, Brhihan Mumbai are with spatial extent greater than 400 sq.km.  Gandhinagar has 416 trees for every 100 people followed by Bangalore with 16 trees, Brihan Mumbai with 15 trees and Ahmedabad with 11 trees. This is contrary to the required green of 9.5 m2/person to meet the ecological demand of humans. Per capita daily respiratory carbon ranges from 540-900 grams (depending on the age and physiology) and a native tree sequesters annually about 6 kg of carbon, necessitating at least 8 trees per person.

Reduced vegetation cover with unplanned urbanization has serious implications for the city’s environmental and ecological health. This highlights the city has crossed the threshold of urbanization evident from a range of psychological, social and health impacts for residents including dramatic increase in recent times of instances such as  higher instances of domestic violence, obesity,  enhanced asthma levels, traffic bottlenecks, road accidents, etc. Overall improvements in human well-being and community vitality necessitate urban planners to maintain at least 33% green cover in the region. In such a case there would be at least 1.15 trees/person in the city.