An Integrated Assessment Method of Water Quality & Quantity Applied to Evaluation of Available Water Resources

Affected by human activity and climate change,substantial changes have taken place in both external environment and internal conditions in China's water resources.In the context of assessment,planning and management of sustainable utilization of water resources,the urgent need is to clarify how much available and regulatory water resources does a river have,under certain production and domestic water consumptions conditions,to satlisfy water quality objective for water functional regionalization and a certain river channel eco-water requirement so as to meet the demand of reducing pollution load for realizing water functional regionalization objective.To this end,this paper addresses the concept of the availabe useable water resources related to both water quality and quantity.An integrated assessment model and method of water quality and quantity,applied to single river section and multiple sections in a river system and basin,are developed.The case study of Luanhe river basin in North China is given as a preliminary explanation of this methodology.It is shown that under the present water use situation,new water use can lead to an increase of 510 million m3 when water quality objective of the river system is satisfied,where the maximum water availability is 43% and the present rate of the Luanhe River is only 30%.However,if the present water use pattern is replaced by reasonable water allocation,the maximum capacity of the available water can be increased to 54%.