基于EFDC的丹江口水库水环境数值模拟分析

发布时间：2019-06-15 17:12

【摘要】：对于湖库区水环境状况进行合理的分析与评价进而对其有效的治理对于保证社会经济持续健康稳定的发展起到至关重要的作用。丹江口水库作为南水北调中线工程的水源地，其水质状况达标与否关系到输水干线沿线居民的身体健康。本文选取丹江口水库作为研究对象，利用目前被广泛使用的环境流体动力学模型EFDC，对丹江口水库2012年水动力及水质情况进行模拟，并依据模拟结果分析了其水动力及水质变化规律。本文首先介绍了水环境模拟的国内外研究情况以及水环境研究发展的新趋势，，阐述了丹江口水库的自然地理状况和目前所存在的水环境问题。之后针对本次模拟所采用的核心算法EFDC，对其算法原理和组成结构进行详细介绍。并根据其输入输出结构建立了符合用户使用习惯的前后处理程序，搭建起适于湖库区的三维水生态系统。建立了丹江口水库的三维水动力学及水质模型。其中水位模拟情况较好，与实测值相比误差仅为0.1%。对于水温的模拟很好的把握了丹江口水库水温分层这一现象，这种现象在夏季表现最为明显，秋季由于垂向掺混作用使得分层现象减弱，到了冬季水体完全混合，分层现象消失。根据流场分布图表明丹江口水库出现由于紊流作用而形成的涡旋，并且流速呈两头大，中间小的格局，上层水流速度受到风速影响较大。本文选用溶解氧、氨氮、总氮、总磷等常用指标作为研究对象。模拟结果表明：溶解氧浓度受温度影响较大，成明显反比趋势，夏季含量低冬季含量高，且同时存在分层现象，表层高于底层。氨氮也同样具备季节性周期变化及分层现象。对于总氮来讲影响其变化的因素主要是库区藻类生长及外源水体汇入。最后利用多元回归分析的方法分别对影响溶解氧和氨氮浓度的因素进行计算，得出影响因素的大小排序，利用参数敏感度分析得出了影响氨氮浓度因素的参数。
[Abstract]:Reasonable analysis and evaluation of the water environment in the lake reservoir area and its effective management play an important role in ensuring the sustained, healthy and stable development of the social economy. Danjiangkou Reservoir, as the water source of the middle route of South-to-North Water transfer Project, whether its water quality is up to standard or not is related to the health of the residents along the main line of water transmission. In this paper, Danjiangkou Reservoir is selected as the research object, and the hydrodynamic and water quality of Danjiangkou Reservoir in 2012 are simulated by using the environmental hydrodynamic model EFDC, which is widely used at present, and the hydrodynamic force and water quality of Danjiangkou Reservoir are analyzed according to the simulation results. This paper first introduces the research situation of water environment simulation at home and abroad and the new trend of water environment research and development, and expounds the natural geographical situation of Danjiangkou Reservoir and the existing water environment problems at present. Then the principle and structure of the algorithm are introduced in detail according to the core algorithm EFDC, used in this simulation. According to its input and output structure, a pre-and post-processing program in accordance with the user's habits is established, and a three-dimensional water ecosystem suitable for the lake reservoir area is built. The three-dimensional hydrodynamics and water quality model of Danjiangkou Reservoir are established. The simulation of water level is better, and the error is only 0.1% compared with the measured value. The phenomenon of water temperature stratification in Danjiangkou Reservoir is well grasped by the simulation of water temperature, which is the most obvious in summer. Due to the vertical mixing in autumn, the stratification phenomenon is weakened, and the stratification phenomenon disappears when the water body is completely mixed in winter. According to the flow field distribution map, the vortex formed by turbulence occurs in Danjiangkou Reservoir, and the velocity is large at both ends and small in the middle, and the upper flow velocity is greatly affected by wind speed. In this paper, dissolved oxygen, ammonia nitrogen, total phosphorus and other common indicators are selected as the research object. The simulation results show that the dissolved oxygen concentration is greatly affected by temperature, and the content of dissolved oxygen is obviously inversely proportional. The content of dissolved oxygen is low in summer and high in winter, and there is stratification phenomenon at the same time, and the surface layer is higher than the bottom layer. Ammonia nitrogen also has seasonal periodic variation and stratification phenomenon. For total nitrogen, the main factors affecting the change are algae growth and exogenous water inflow in the reservoir area. Finally, the factors that affect the concentration of dissolved oxygen and ammonia nitrogen are calculated by multiple regression analysis, and the order of the influencing factors is obtained, and the parameters of the factors affecting the concentration of ammonia nitrogen are obtained by parameter sensitivity analysis.
【学位授予单位】：中国地质大学（北京）
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TV697.2;X143

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