A SYSTEM DYNAMICS APPROACH TO A COMPREHENSIVE ASSESSMENT OF WATER STRATEGIES: A CASE STUDY OF NORTH CHINA

In this study, a new approach for identifying the optimal water strategy is presented, for the purpose of achieving sustainable development of water resources, incorporating System Dynamics (SD) and the Comprehensive Benefit Assessment model. A complex SD model is therefore developed using the Vensim PLE SD software package, which reflects interactions between water resources, ecology, society and the economy. On this basis, we advance a Comprehensive Benefit Assessment model to give an all-around assessment of a chosen water resource system. A case from North China has been studied to illustrate the applicability of the new approach. The credibility and validity of the SD model is confirmed with datasets from the years 2004-2011; the average simulation error is only about 2.6%. The water supply and demand of North China in 2030 is predicted, which foretells a huge water shortage. The new approach is then employed to assess the impacts of the four water strategies: storage, desalinization, water saving and sewage treatment. Results show that when the investments in water conservancy facilities reach 0.5% of the annual GDP, the maximum comprehensive benefit is obtained. Developing water desalination technology has been proven not to be an economical measure in the short term. The development of water-saving and sewage treatment technology has a positive impact on increasing the water supply, narrowing the margin between supply and demand, enhancing sewage utilization, and improving the ecological environment. However, excessive investments will slow down the pace of economic development.