Urban Hydrology in Hong Kong
June 14, 2004
Hong Kong Island, though densely populated, nevertheless has a surprising amount of tropical rain forests. The urban development is found mostly about the coasts. This photo is one I took while running up the Central Green Trail in Hong Kong on May 1, 2004. Note the catchment work. In built up areas having high annual rainfall, such as Hong Kong, runoff can pose serious problems -- locations having a large amount of impervious areas are susceptible to urban flooding. However, if urban sewerage systems are well designed, they can remove surface water runoff quickly and efficiently. This is typically achieved by widening the stream channel, smoothing the bottom with concrete and maintaining flow efficiency by filtering rubbish to prevent the system from becoming clogged.