【作者】 翟俊；

【导师】 何强；

【作者基本信息】 重庆大学 ， 市政工程， 2008， 博士

【摘要】 水环境管理是一个复杂的系统工程,它涉及包括污染源状况,污染物在水体中的迁移分布,城市分布、经济区划、流域状况、控制断面等在内的海量信息。且这些信息往往随时间改变,是一个动态过程。如何对此海量信息进行高效管理和分析,是当前水环境管理的重要课题之一,迫切需要高水平的管理信息系统作支持。对于自然水体中普遍存在的紊流流动及其中的污染物迁移扩散的模拟也是当前科学研究的一个热点。近年来出现的分形理论等非线性科学为解释和描述随机性很强的紊流现象提供了较好的理论基础。论文在国家“十五”科技攻关课题“三峡库区水环境安全关键技术研究与示范”(2004BA604A01)的资助下,将分形理论引入紊流水质模拟中,提出了分形紊流扩散模型,并与K-ε双方程水力模型相配合,完成了长江万州城区段的三维水力/水质模拟研究,对污染物在紊流流体中的扩散迁移规律进行了较深入的研究,实现了分形理论在紊流水质模拟中的成功应用,并完成了复杂边界条件自然河流中多个污染源复合污染带的三维模拟。同时,将GIS技术与水力/水质数学模型相结合,开发了基于GIS的三峡库区水污染(应急)管理信息系统,可以为三峡库区水环境科学管理提供先进的技术手段和决策支持。以VB为计算机程序开发语言,以ArcGIS Engine为GIS平台,实现了GIS、数学模型、数据库的全面集成,所开发的三峡库区水污染管理信息系统软件拥有自主知识产权。该系统具备了污染源动态管理、污水厂适时监控、水体水质查询及评价、流场和浓度场模拟等水环境管理和决策支持功能。同时,论文根据当前水环境管理的需要,在所开发的系统中强化了突发性污染事故应急管理功能,可自动统计出各种污染事故产生的污染带在不同时间的区位及影响范围,为突发性污染事故的应急管理提供了软件平台。开发了适合GIS系统的三峡库区一维(整个库区江段)、二维(主要城市江段)恒定流动态水质数学模型,能够同时模拟众多点污染源和面源污染产生的污染带和污染物的迁移扩散过程,满足水质模拟和污染事故预警对数学模型的要求。通过实际监测数据,验证了适合长江三峡库区水文条件的模型参数。通过系统对成库后库区一维总体水质的模拟分析,在沿江主要点污染源得到有效治理后,库区长江总体水质状况较成库前好,且水位越高,趋势越明显。从污染物单项指标的模拟结果来看,库区长江COD浓度高峰主要出现在主城至涪陵的城市密集区江段,这一区域是城镇生活污水和工业废水的主要来源。而NH3-N、TN、TP等营养性污染物指标的浓度高峰则主要出现主城至涪陵的城市密集区和万州之后至重庆出境的江段,且越靠近库首,浓度越高,说明在库首区域营养性污染物负荷相对较高,水土流失等面源污染是其主要的污染源。成库后,COD指标在整个库区均处于Ⅰ类或Ⅱ类水质标准;NH3-N指标在库区主要处于Ⅱ类水质指标,在主城区和库首则处于Ⅲ类水质指标;以2003年入境水质作为起始断面水质时,TN和TP指标以湖、库标准来衡量,TN指标浓度则将超标,总体处于Ⅳ类和Ⅴ类水质标准,TP指标也将超标处于Ⅲ类和Ⅳ类水质标准。从系统对库区干流主要城市江段二维模拟结果来看,在库尾的主城区江段,由于成库前后水文条件变化不大和受到水库回水影响,污染带略有扩大。在库中和库首的江段,在输入相同负荷的情况下,污染带有明显减小,特别是在175m水位下,污染带减小趋势最为明显。万州江段的三维水质模拟研究表明,在成库后水流速度显著减小,水体底层紊动掺混能力明显减弱,铅直方向上的水质分布不均匀性非常明显。万州城区江段岸边的表层水质较差,而中层和底层水质则相对较好。库区排污口附近的污染混合区将会由天然河道的狭长型向着短宽型发展。在输入相同污染负荷的情况下,长江表层污染物带的长度略微有所减小,但宽度却增加了一倍。论文以三峡库区长江为研究对象,开展了基于紊流理论的三峡库区典型河段三维水质模拟研究,同时开发了基于GIS的三峡库区水污染(应急)管理信息系统。其研究成果对提高水污染(应急)管理水平具有直接推动作用,对于紊流流动、紊流扩散等“无序”、非线性问题进行了探索性的研究,有着重要的理论意义和实用价值,对相似河流和地区的水污染管理和水质模拟研究也有重要的参考价值。更多还原

【Abstract】 Water environment is a very complex system, which involves numerous information, such as pollution source, passive scalar transportation and disffusion in turbulence, watershed land-use, economic situation and the industrial distribution, monitoring sections, etc. The water environment is a dynamic process/system. So, how to make a high efficient management and analysis on the nemerous informations has become a hot research topic in the fields of water environment management. A hign quality Managemet Information System seems necessary. Turbulent flow and the pollutants disffusion are two very diffucult courses for the researchers to face, which have confused the world-wide researchers for a centry. This dissertation made an successful integration of GIS and Mathmatic Model-Base, and developed a GIS-based water pollution management and emergency reponse information system for Three Gorges Reservior Area(TGRA), Yangetze River, which delivered an adanced Spatial Decision Support System(SDSS). Fractal theory and analysis method were applied in turbulent water quality modelling. A fractal turbulence diffusion model was developed and uesed for the 3D water quality modelling in Wanzhou section of Yangetze River, with help of K-εtwo equation hydraulic model. The dynamics of the passive scarlar diffusion and transportation in turbulence was carefully studied. This Ph. D. thesis is one of the study outputs of the National Tenth-Five-Years Scientific and Techenical Research Project: Research and Demonstration on the Key techenologies for the Water Environmental Safty in Three Gorges Reservoir Area.A 3D K-εtwo-equation hydraulic model was applied for dynamics of the velocity in Wanzhou section of Yangetze River, Base on which the fractal turbulence diffusion model was developed and uesed for the 3D water quality modelling. A successful case of combination of fractal turbulent diffusion model and K-εhydraulic model has been showed, which is an innovation that fractal theory was applied to model compounded pollution area from multiple-sources in big and natural river system.In the development of the water pollution SDSS, Virtual Basic(VB) was selected as the software developing language, and ArcGIS Engine as GIS platform. A fully integration of GIS, Model Base, and Date Base was achieved, and consequently, a copyright-self-owned software was developed. The new software has several kinds of powerful functions for decision-making, including pollution source management, WWTP up-to-date monitoring, water quality query and assessment, velocity and quality modeling. The function of emergency response after the pollution accident happening was also enhanced in the software. The influent area from the pollution accident can be calculated and displayed out in time-serial.1D and 2D water quality models suitable for integration in GIS software have been developed. The compounded pollution area from multiple-sources can be simulated in big and complex situation river system through the developed models. The mathematical models have been validated by the existing monitoring data.According to the research result of 1D water quality simulation on the whole length of the Yangtze River in Chongqing area, the water quality of Yangtze River will be improved after finishing the construction work of the big dam with water level rising, if the main point-source pollution can be treated efficiently. The peak point of COD concentration will appear in the section between Chongqing main-town and Fuling city, which area has the high density of urban area, and is the main source district of domestic and industrial wastewater. While the peak sites of nutrient pollutants, such as NH3-N、TN、TP, will appear in the river section downstream to Wanzhou, where non-point source pollution, such as soil-erosion is heavy. After finishing the dam construction, COD concentration of TGRA will remain in ClassⅠorⅡ, NH3-N concentration will remain in ClassⅡorⅢ(the river section in Chongqing main town and near to the dam will remain in ClassⅢ). The concentration of TN and TP was predicted to exceed the desired water quality standard, and stay in ClassⅣorⅤ. The situation of TN is poorer than TP.According to the research results from 2D water quality simulation for the urban section of Yangtze River in TGRA, the near-bank water pollution belt in Chongqing main town will expand slightly, due to that the water level will not be influenced significantly; while in river sections near to dam or at the middle of the reservoir, the near-bank water pollution belt will minish obviously, especially when the water level is in 175m height.The 3D water quality simulation for Yangtze River in Wanzhou Urban area showed a very water quality gradient will appear in vertical direction of the Yangtze after the reservoir formed, and the turbulent mixing capacity will decrease at the bed of the river due to the low velocity. The surface water quality is relative poorer than the middle or bottom part. The near-bank pollution belt will be changed from narrow-and-long style to short-and-wide style. Through the model simulation, the width of the pollution belt will double, while the length will decrease slightly after the reservoir forming, comparing with the natural river situation with the same pollutant load.This dissertation selected TGRA as research area, and applied fractal theory into 3D turbulent diffusion in complex natual river,and developed a GIS-based software about water pollution management and emergency reponse. The research output is helpful to elevate the management level in the field of water pollution and emergcy response. The dissertation is a pioneer for the research on fractal application in the“nonregular”and“nonlinear”phenomenia like turbulent flow and turblent diffusion, which is meaningful to scientific research and actual use, aslo a good refernce for silimar revers or area.更多还原