China’s largest and most populated city Shanghai, built on the marshy banks of the Huangpu river, is slowly sinking, though at a slower rate than before, a report said on Thursday. The modern metropolis is home to nearly 17 million people and although over exploitation of underground water is the main cause, its 3,000 high-rises built on soft, wet ground have contributed to the problem of subsidence, experts said. The eastern port sunk 8.7 millimetres last year, more than the target rate of five millimetres a year hoped for by 2010, the Shanghai Daily reported, citing a geological survey.