Projects may speed up sedimentation rate

Reading the report headlined 'Action urged to save key wetland' (South China Morning Post, September 16), I could not help but wonder whether the river channelisation projects in the New Territories were ever thoroughly thought out.

Sedimentation can be seen as a natural geomorphological process.

However, academics agree that channelising rivers into straight concrete and barren structures induces higher river velocities and quicker sedimentation downstream, because of the lack of suitable vegetation.

Channelisation projects attempt to tackle flooding of floodplains, but these same projects are potentially intensifying and hastening the rate of sedimentation along Deep Bay, and thereby threatening the long-term existence of the Mai Po marshes.

MARK CHAN

Tai Po