Demand-supply balance of river basin water resources of different qualities

The significance of research of the demand supply balance of water resources of different qualities is discussed, and a specific research method is put forward. The key point of the method is to compare the volumes of water of different qualities taken by water users with the volumes of water resources available in the same region, so as to obtain the information on shortage or surplus of water of different qualities. Then, an analysis is made of the volume of water consumption in 1998 in the Taihu Lake Basin. The result shows that, owing to the high rate of water reuse and water diversion from the Yangtze River, the problem in water volume does not exist, but the water quality induced water shortage is very serious: the water of grade III and grade V is lacked. Furthermore, the application of the above method to planning is discussed.