Metro rail may result in increase in temperature

Metro rail may result in increase in temperature

The Hindu

412 trees to be felled for the project

# More than 1.8 lakh tonnes of steel and loads of cement to be used
# BMRC plans to grow ivy plant on the bridges

BANGALORE: While the proposed metro rail may bring cheers to people affected by high-levels of air pollution, it brings in a new cause of concern: increase in city's temperature by one or two degrees Celsius. Also, 412 trees will be felled to make way for the project.

The rise in temperature is owing to the possible use of more than 1.8 lakh tonnes of steel and loads of cement for the concrete structure. The 33-km, Rs. 6400-crore metro, to become operational by the end of 2011, will have 26 km of bridge, cutting the city into four divisions. The project will have 32 stations. Of them 23 will be elevated.

Environmentalist and former bureaucrat A.N. Yellappa Reddy said the bridges would be 8 to 10 degrees hotter than the ambient air when there is bright sun. The series of heat islands would cause discomfort for those living on either side. He said it was a rough estimation that the metro's bridges would lead to increase in temperature by one or two degrees Celsius. The city's temperature averages 33.4 degree Celsius in April and May.

The issue came up in a recent meeting of the Environment Monitoring Committee (EMC) of Bangalore Metro Rail Corporation Limited (BMRC), chaired by Mr. Reddy, who is its member.

The meeting decided to grow ivy plant on the bridges as has been done in Singpaore (Ivy plant can completely cover concrete walls). Mr. Reddy reportedly suggested that the metro stations should have special flowering plants and species. Each month different flowers should blossom, he said.

Growing plants

Mr. Reddy told The Hindu that the concrete bridges would take more time too cool off and they would radiate heat even till midnight in hot summer.

This was a serious problem. He said the BMRC should plan for pots and source of mud to grow creepers and climbers. He hoped that the EMC would come out with an action plan.

Ad hoc measure

Anand Prakash, an architect, says that growing ivy and creepers were an ad-hoc measure for a serious problem. He was not convinced that this would make the required impact. A deeper understanding of the problem and a well-thought out and concrete plan of action was required.

Mr. Reddy agrees that the creepers and ivy may only reduce the impact and not solve the problem fully. Giving shade would be ideal solution, he said.

The drop in the pollution level is because it will reduce consumption of fuel by private vehicles. It is predicted that two-wheelers population will come down by 30 per cent and three-wheelers by 20 per cent when the metro becomes operational. This, it is hoped, will reduce consumption of fuel by 7 lakh litres a day bringing down the vehicular emissions by more than 300 tonnes each day, the assessment said.

On the other hand, 412 trees adding up to 545 tonnes, will be lost for the project. BMRC has already taken up plantation of 7,000 saplings through the Karnataka Forest Department, 5000 through the BDA and 3,000 through the Bangalore Mahanagara Palike at a cost of Rs. 33 lakh. Of them, more than 8,000 saplings have already been planted, according to BMRC sources.

An architect, however, says this not enough for a Rs. 6,400-crore project. "It is peanuts," he said. He pointed out that apartments spent Rs. 5 lakh for landscaping. Mr. Reddy says a five-year plan of action was likely to be worked out in the forthcoming meetings of the EMC.