[NEW DELHI] Climate change would lead to higher wind speeds in offshore locations around India, a peninsula with long coastline, as an increase in the earth’s temperature would mean a corresponding rise in air pressure and wind activity, says a new study.
Published this month (4 May) in Ocean Engineering, the study simulated the effect of climate change on design wind — the wind speed which can be equalled or exceeded once in a specific number of years — which is linked to the expected lifespan of harbour, coastal and offshore structures.
“Future structures should be built considering the effects of climate change and safety of existing structures needs to be verified. When design wind changes, the corresponding forces change, and one needs to have stronger structures to withstand this,” says Makarand Chintamani Deo, professor of civil engineering at the Indian Institute of Technology (IIT), Mumbai, and co-author of the study.
The model was built upon seven-year (1998-2005) wind observations made available by the National Institute of Ocean Technology, Chennai. The data was collected through a floating device that measures met-ocean parameters, called a wave rider buoy, at two locations: one off Goa on the west coast, and the other off Machilipatnam, to the east.
For the two locations, the increase in a 100-year wind period, where the effect of climate change is taken into account, compared to when it is not, varied from 44 per cent to as much as 74 per cent.
Deo agrees that the varying sample sizes — seven-year data to simulate 100-year speeds — could be a source of uncertainty in the results. But he told SciDev.Net that while “the magnitudes shown can vary owing to so many alternative methods to adopt, qualitatively the conclusion is difficult to change.”
Deo has co-authored another paper to be presented at the Ninth International Conference on Hydro-Science and Engineering at IIT Chennai in August that, apart from wind speed, also simulates wave heights to incorporate the effect of climate change. Wave heights in this model are seen to be 25 per cent to 59 per cent higher than when the effect is not taken into account.