Development and water quality in the Kam Tin basin, Hong Kong

Abstract

The economic development of Hong Kong has meant that some once rural areas have been transformed. They have become characterized by low-density housing, open storage and makeshift factories, in addition to agriculture. This change in land use may have consequences for water quality especially as many areas are not connected to mains sewerage. In the Kam Tin basin, under baseflow conditions, water samples from the river in the developing lowland are characterized by much higher concentrations of calcium, magnesium, potassium, nitrate-nitrogen and dissolved phosphorous, than an undisturbed upland tributary. The Kam Tin River also has much greater suspended solids concentrations than the upland stream and a significant amount of floating debris and rubbish which is never seen in the upland tributary. More attention needs to be given to sewerage and waste disposal in the basin. Runoff pH appears little influenced by the acid rain input.