Water-scarce & unlivable: that's B'luru in 2020

Four years from now, 93% of Bengaluru’s landscape will be filled with paved surface or built-up area, resulting in a drastic decrease in open spaces and green cover. In short, the Garden City has a grim, water-scarce, unlivable and non-resilient future.

That’s the warning given in Bengaluru Vision 2020, a research paper published in this week’s ‘Current Science’ magazine. The paper is authored by T V Ramachandra and Bharath H Aithal, scientists from the Centre for Ecological Sciences, Indian Institute of Science, Bengaluru. It is a follow-up of their previous study, which Deccan Herald reported in May this year.

The paper lists seven major implications of urbanisation on Bengaluru.
“Bengaluru would witness 93% of urban cover and only 7% of open spaces and green cover in 2020. This would make the region GHG-rich, water-scarce, non-resilient and unlivable, depriving the city dwellers of clean air, water and environment,” the study says.

Bengaluru saw a whopping 1,005% concretisation or increase of paved surface from 1973 to 2016.

In addition to higher air pollutants and sharp decline in groundwater table, the urban sprawl has reduced green spaces (88% decline in vegetation) and wetlands (79% decline) in this period,” the paper says.

The researchers highlight the drastic reduction in green spaces due to unrealistic urban growth in the last four decades. “There are only 1.5 million trees to support Bengaluru’s population of 9.5 million, indicating one tree for every seven persons in the city.

This is insufficient even to sequester respiratory carbon (ranges from 540 to 900 g per person per day).”

The study quantified the trees in the region using remote sensing data with field census. Citing an increase of three degrees celsius in surface and atmospheric temperature, the study attributes it to loss of natural cover (trees and waterbodies) and an increase in artificial materials having high heat conductivities.

The study observed a drastic increase in electricity consumption [from 14,000 to 17,000 units (kWh) per year] and contribution of 43.83% (in greater Bengaluru) emissions from the transport sector on account of large-scale use of private vehicles and 60% of total emissions due to lack of an appropriate public transport system. The water table declined to 300 metres from 28 metres, and 400–500 metres in intensely urbanised area such as Whitefield over 20 years.

Encroached, polluted lakes
Almost 98% of the lakes have been encroached upon by illegal buildings and 90% of the lakes are sewage-fed, according to the field studies of 105 lakes in 2015–16.
“Indiscriminate disposal of solid and liquid waste (rich in organic nutrient) has enriched nitrate levels in the surrounding ground water resources, threatening the health of residents such as kidney failure and cancer,” the study says. The paper also cites large-scale fish mortality in recent months to underline the level of contamination.

On flash floods, the paper blames the conversion of wetlands to residential and commercial layouts by removing the interconnectivity in an undulating terrain. “Encroachment of natural drains, alteration of topography involving the construction of high-rise buildings, removal of vegetation cover, and reclamation of wetlands are the prime reasons for frequent flooding even during normal rainfall post 2000,” it states.