海平面上升背景下上海市水源地供水安全预警系统研究

Research on Early Warning System for Fresh Water Supply in Shanghai on Rising Sea Level Background

随着气候变暖和海平面上升导致的河口盐水入侵增强,上海这一地处长江河口区特大型城市的主要水源地供水安全面临严峻挑战。为此,海平面上升背景下上海市水源地供水安全预警研究迫在眉睫。本文在分析上海市水资源供需风险因子的基础上,研究上海市水源地供水安全预警系统及其功能结构,将上海市人均水资源量、供水保证率、万元GDP用水量、盐水入侵时上海市水源地不可取水天数作为上海市水源地供水安全的预警指标,利用熵权模糊物元法计算4个预警指标的权重,通过加权欧氏距离确定2020年、2030年和2050年上海市水源地供水安全的预警等级,并提出上海市水源地供水安全预警的对策、建议和措施,为相关部门科学分析和有效保障上海市的供水安全提供决策依据。

Shanghai, a megacity located in the Yangtze estuary, is the economic, financial, trade and shipping center of China. Saltwater intrusion caused by sea level rise（SLR）will affect the fresh water supply in Shanghai. At present, water shortage has become the major risk factor of water supply in Shanghai because 70% of fresh water will be supplied from reservoirs in the Yangtze estuary. Therefore, in order to maintain long term social stability and development in Shanghai and ensure the safety of fresh water supply, it is necessary to explore an early warning system for the fresh water supply impacted by SLR in Shanghai. The risk of fresh water supply in Shanghai can be divided into water supply risk and water demand risk. Water supply risk includes SLR and the Yangtze runoff, while water demand risk is caused by the demand of industrial water, agricultural water, domestic water and eco-environmental water. On the basis of analyzing the imbalance between fresh water supply and demand, this paper has proposed a research idea and implementation scheme of the early warning system and introduced Microsoft Visual Studio. The early warning system is designed and realized by adopting browser/server structure which consists of data layer, business layer, model layer and response layer. Users can make early warning of fresh water supply in Shanghai through the functions of data management, scenarios simulation, early warning level assessment and spatial analysis, and each function module of the system is implemented by using JavaScript and C# language. In this paper, water resources per capita in Shanghai, guarantee rate of water supply, water consumption per 10,000 yuan of GDP and the longest duration that the chlorinity exceeds 250mg/L, were selected as indexes of the early warning system, and the entropy fuzzy matter element model was combined with the weighted Euclidean distance to estimate the early warning level of each reservoir in the year of 2020, 2030 and 2050. By this method, the early warning level can be divided into no alert, light alert, moderate alert, heavy alert and severe alert. The paper also has proposed some responses, suggestions and measures about the water supply safety in Shanghai, aiming at providing the relevant departments with some policy-making bases to ensure an effective guarantee and scientific analysis of fresh water supply in Shanghai.