A Beijing government think tank has made two ambitious proposals to tackle the capital's water shortage and air pollution, one involving the construction of a huge canal to Tianjin and the other creating a massive artificial fresh air intake in the municipality's northwest. But some scientists are not impressed, suggesting that the plans would be next to useless in easing environmental pressures. The Beijing Academy of Social Sciences (BASS) outlined the plans in two reports released this week. The first proposed building a canal - a kilometre wide and 160km long - from Tianjin to the capital to carry desalinated, treated potable water sourced from the polluted Bohai Gulf. The canal could also ease smog by allowing dry land along its banks to be irrigated to stop fine dust particles wafting into the capital, BASS said. Beijing would have to desalinate seawater from the Bohai Gulf to ease the city's water shortage as its groundwater ran out, said Shi Changkui , the report's lead author. The other report suggested building two townships in the northwestern suburbs of Nankou and Machikou to provide a wind portal to central Beijing. The authors envisaged using the local mountainous terrain as a natural "ventilation system" drawing wind from northwest China that could be "scrubbed" to remove much of the sand it carries in winter and spring. The report listed three wind belts for Beijing that would make best use of the city's topography, and urged the government to devise a plan to transform the Nankou-Machikou area from a belt of polluting heavy industries into a revitalised green zone. "Our present city planning attaches little importance to the protection and use of wind environments in suburban areas," said Ding Jun , associate researcher at the BASS Economics Research Institute and author of the report. However, Hu Fei , a researcher at the Institute of Atmospheric Physics at the Chinese Academy of Sciences, dismissed the proposals as "ridiculous suggestions from non-professionals". He said Beijing's air pollution was a systemic problem, and removing dust in a certain area would have very little impact. "It's like a dietary supplement that keeps a healthy person fit but won't cure someone who is already ill," he said. "Beijing is already very ill." Xia Qing , former deputy director of the Chinese Research Academy of Environmental Sciences, said the canal proposal not only risked raising soil salinity, but also defied physics. "The land is high in the west and low in the east. They're asking water to flow uphill," he said.