BENGALURU: Ecological scientists at the Indian Institute of Science (IISc) have come out with a paper listing various changes over the years that have left the cityscape in dire straits.
The scientists say the increasing use of air conditioners and other high-energy consuming machines, as well as the construction of concrete jungles have led to an increase in temperature in urban areas.
Urbanisation and the consequent loss of lakes has led to a decrease in catchment yield, water storage capacity, wetland area, number of migratory birds, flora and fauna diversity and groundwater table.
Prof T V Ramachandra, one of the authors of the paper titled ‘Conservation of Wetlands to Mitigate Urban Floods’, writes, “The uncoordinated pattern of urban growth could be attributed to a lack of good governance and decentralised administration, evident from the lack of coordination among many parastatal agencies, which has led to unsustainable use of land and other resources. The mitigation of frequent floods and the associated loss of human life and properties entail the restoration of inter-connectivity among wetlands, restoration of wetlands (removal of encroachments), and their sustainable management.”
The paper has been co-authored by Ramachandran, Uttam Kumar and Bharath H Aithal from the Centre of Ecological Sciences at IISc.
Their findings point to the decline in green spaces and wetlands, which has affected natural resources and depleted the groundwater table.
Rise in Flooding
As land is converted from fields or woodlands to roads and parking lots, it loses its ability to absorb rainfall. The scientists say encroachment of natural drains, alteration of the topography involving the construction of high-rise buildings, and removal of vegetative cover are the main reasons for frequent flooding post year 2000, even in times of good rain.
Meanwhile, as water bodies disappeared, the water table declined. The paper says, “Water table has declined from 28 m to 300 m over 20 years after the reclamation of lakes with (their) catchment for commercial activities.”
Heat Island
The paper says that the decreasing vegetation and increasing heat discharge by energy-consuming devices such as air conditioners, glass buildings and concrete constructions have increased the city’s temperature.
Bengaluru’s urban pockets are hotter than the non-urban ones by 2-2.5 degrees Celsius.
The architecture of newer buildings is also leading to increased consumption of energy. The rise in the number of vehicles has led to high pollution levels and traffic bottlenecks. And mismanagement of solid and liquid waste has added to the mess.