Climate change could see half a reservoir of Hong Kong’s potable water evaporate per year, green group says
Global warming might cause 7.3 million cubic metres of water to dry up every year by the turn of the century
Warmer temperatures brought about by climate change could see up to 7.3 million cubic metres more of Hong Kong’s potable water – about half of the Shing Mun Reservoir – literally evaporate every year by the end of the century, an environmental group has warned.
Rainfall helps offset evaporation from reservoirs in most years, but Green Power said the lack of necessary research would jeopardise the city’s long-term water supplies as global warming caused more extreme weather patterns such as droughts and floods, which can contaminate freshwater sources.
“We won’t take this seriously now but if droughts prevail over southern China, our water supply from the Dongjiang could be affected,” said Cheng Luk-ki, Green Power’s head of scientific research and conservation. He was referring to the mainland river system that provides Hong Kong with more than three-quarters of its freshwater needs.
The problem of reservoirs drying up has been deemed pressing enough for other cities to warrant action.
Last year, drought- plagued Los Angeles filled its Van Norman reservoirs with “shade balls” – plastic spheres designed to block sunlight in the hope of reducing water vapour escaping into the atmosphere. Israel has been doing something similar.
Even rainy Singapore recently tried out a food-safe powder – which forms a thin, single-molecule film over the surface of water – at Bedok reservoir to curb evaporation, which costs the city state 20 per cent of potable water annually.