【作者】 徐丹；

【导师】 付湘；

【作者基本信息】 武汉大学 ， 水文学及水资源， 2019， 硕士

【摘要】 城市河湖水质恶化已严重影响城市形象与人们的生活品质,在一定程度上制约了城市的发展,成为亟待解决的社会问题。而随着灌区的发展,除传统农业生产之外,如何发挥更大的经济效益与社会效益也是灌区不断追求的目标。灌区水资源丰富,研究在保证农业生产的情况下,将多余的清水供往城市湖泊,对于改善城市湖泊水质、提高灌区的经济效益具有很强的现实意义。本文首先在考虑工业、农业、生活等用水户的基础上,将城市生态环境作为灌区内用水户,建立灌区水资源优化配置模型进行配置,得到了灌区可向城市提供的生态环境用水。然后,为使生态环境用水充分发挥作用,建立城市湖泊二维水动力水质模型,采用多种供水方案对不同状态下的城市湖泊进行了水质改善模拟。最后,通过构建的方案评价指标体系对各种供水方案进行比选,得到最优调水流量与水量。本次研究以南昌市和与之相邻的赣抚平原灌区为研究实例,主要研究内容如下:(1)建立灌区水资源优化配置模型,为改善城市湖泊水质提供水量依据。考虑灌区农业、工业、生活以及城市生态等用水户的用水,以灌区社会效益与经济效益最大化为目标,建立了多目标水资源优化配置模型。采用约束法与权重法相结合的形式对模型进行求解,得到灌区全年与用水高峰期两个时间尺度下的配置结果。赣抚平原水资源优化配置的结果表明:灌区可为南昌市提供一定量的生态环境用水用于湖泊水质改善,但可提供的水量受来水情况与决策倾向影响较大。(2)建立二维水动力水质耦合模型,进行了城市湖泊水质改善模拟。利用南昌市青山湖、象湖与艾溪湖的实测水底地形资料,使用MIKE 21建立了二维水动力水质耦合模型。通过实测水位、水质数据对模型进行重要参数率定和验证,得到了可用于水质改善模拟的可靠模型。采用多种供水方案对处于不同水质水量的湖泊进行水质改善模拟,三个湖泊的模拟结果表明:模型能较为准确地模拟湖泊的水动力与水质情况,模拟的多种生态灌区供水方案可为实际调水提供参考。(3)构建水质改善方案评价指标体系,制定优化调水方案。建立了考虑城市湖泊水质改善时间、水量、湖泊水质与水动力条件的多目标评价指标体系,能计算出城市湖泊在不同水量、水质状态下进行调水所需的最优流量。将指标体系应用于南昌市青山湖、象湖与艾溪湖后,计算出三个湖泊不同状态下的最优水质改善流量,求得南昌市河湖单次水质改善所需水量,评估了进行赣抚平原灌区水资源配置时分配给南昌市生态环境的水量。实例研究结果表明:南昌市三个湖泊处于不同水质和水量状态时最优水质改善流量存在较大差异;仅靠赣抚平原灌区进行生态环境调水,不能使南昌市河湖在全年均维持较好的水质状态。更多还原

【Abstract】 The deterioration of water quality in urban rivers and lakes has seriously affected the image of the city and people’s quality of life,even restricted the development of the city,and become a serious social problem.With the development of irrigation districts,besides traditional agricultural production,how to exert greater economic and social benefits is also the goal of irrigation districts.Irrigation area is rich in water resources.It is of great practical significance to study water diversion under the condition of ensuring agricultural production for improving the water environment of urban lakes and improving the economic benefits of irrigation area.Firstly,on the basis of considering industrial,agricultural,domestic and other water users in the irrigation area,the optimal allocation model is established and the ecological environment water is obtained.Then,in order to make full use of the water for ecological environment,a two-dimensional hydrodynamic water quality model of urban lakes was established,and the water diversion of urban lakes under different conditions were simulated by various diversion schemes.Finally,through the evaluation index system of diversion,the optimal water diversion flow is selected.This study takes Nanchang City and Ganfu Plain irrigation area as the research object.The main research contents are as follows:(1)The optimal allocation model is established to provide basis for water diversion.Considering the water consumption of agricultural,industrial,living and urban ecology users in irrigation area,and aiming at maximizing social and economic benefits of irrigation area,an optimal allocation model is established.The model was solved by the combination of constraint method and weight method,and the optimal allocation results were obtained at the two time scales of the whole year and the peak period of water use.The results of optimal allocation of water resources in Ganfu Plain show that the irrigation area can provide a certain amount of clean water for water diversion into Nanchang City,but the amount of water available is greatly affected by the situation of incoming water and decision-making tendency.(2)A two-dimensional hydrodynamic-water quality coupling model was established to simulate water diversion.Based on the measured bottom topographic data of Qingshan Lake,Xianghu Lake and Aixi Lake in Nanchang City,a two-dimensional hydrodynamic water quality model was established by using MIKE 21.The important parameters of the model are calibrated by the measured water level and water quality data,and then the model is validated.Various schemes are used to simulate the water diversion of lakes.The simulation results of the three lakes show that the model can accurately simulate the hydrodynamic and water quality of the lakes,and the simulated water diversion schemes can provide reference for the actual water diversion.(3)The evaluation index system of water diversion is constructed,and the scheme is optimized.A multi-objective evaluation index system considering the time,quantity,water quality and hydrodynamic conditions of water diversion is established,which can calculate the optimal flow for water diversion of urban lakes.After applying the index system to Qingshan Lake,Aixi Lake and Xianghu Lake in Nanchang City,the optimal water diversion flow of three lakes under different conditions is calculated,the water requirement for single diversion of water in Nanchang City is obtained,and the water requirement for the ecological environment of Nanchang City is evaluated.The results show that the optimal water diversion flow of the three lakes in Nanchang is quite different when they are in different water quality and quantity states,and the ecological environment water supply in Ganfu Plain irrigation area is insufficient.更多还原