Evaluation Criteria and Model for Risk Between Water Supply and Water Demand and its Application in Beijing

In China, studies on water supply and water demand balance have received much attention, but risk between water supply and water demand lacks the same focus. This paper presents evaluation criteria of risk between water supply and water demand, which includes threat, susceptibility, and vulnerability. A new quantitative definition of threat is given based on fuzzy probability; Susceptibility is proposed for evaluating the inherent state of the water resource systems; Vulnerability is qualitatively defined and computed in terms of economic losses. A model for risk evaluation is developed based on the maximum entropy principle and discriminant analysis. Risks in Beijing, used as a case study, are evaluated under different scenarios of inflow. The results show that all the risks in 2020 are first or second grade. After using reclaimed water and transferred water, the third grade and fourth grade risk account for 75 %, with 25 % of the first grade and second grade risk. Therefore, risks are still high in the situations of low precipitation periods.