Modeling of the water supply system in the city of St. John's, Newfoundland.

摘要

Water resources management in the City of St. John's, Newfoundland, is a significant issue because of the intertwined social, economic and environmental concerns. Many sophisticated water management computer models faltered in the past because they are mathematically obscure and overly ambitious in attempting to optimize solutions to real world problems. The best approach is to build a straightforward and flexible tool to assist, not substitute for, the users of the models. In this study, an integrated computer based water management system is developed using the water evaluation and planning program (WEAP), to offer a professional and practical tool to study the current and future water supply and demand systems, regarding, but not limited to, the changes in population, industry, agriculture, and regulations in the city. The modeling efforts were based on a comprehensive study on the city and its surrounding areas, the Windsor Lake watershed, nearby reservoirs, water and waste water treatment facilities, and water supply systems, assuming specific conditions with corresponding projections into the future. Available data on the water supply and management systems in St. John's were collected and compiled, covering meteorological, hydrological, environmental, managerial, and social-economic aspects. An integrated water supply database for the city was also developed based on the geographical information system (GIS) and database techniques. The feasibility and capability of the model, developed using WEAP graphical user interface, have been examined through a real-world study on the city. A manifest of this is embodied in the results presented for multiple scenario analyses. The results indicated that the annual unmet demand is predicted as 1.680 x 106 m3 , 1.711 x 106 m3 , 1.773 x 106 m3 , with respect to a reference scenario of 1.586 x 106 m3 , and the cumulative supply requirements are 2563 x 106 m 3 , 2594 x 106 m3 , 2656 x 10 6 m3 , with respect to a reference of 2469 x 10 6 m3 , over the period of 2000-2030 under the three scenarios. The model developed should evolve into a useful tool in decision making as the interests of jurisdictions considered with increasing awareness and concern on water resources and supply/demand system management as well as its sustainable development under changing environmental conditions. ii