瓯江口潮流数值模拟

建立了时间二次插值的三角形网格显式差分数学模型,从而提高了原三角形网格显式数学模型［1］的稳定性和精度。使用三角形网格全自动剖分技术进行网格剖分,使用"干湿"判别法处理了露滩问题,用两套节点关系处理潜堤问题,对大范围(既有细长河道又有大面积海区)、多岛屿、地形及流态复杂的瓯江口海区的潮流场进行了成功的模拟。并根据模拟结果,对瓯江口海区的潮流特征进行全范围的分析介绍。     

洞庭湖水位变化对水质影响分析

长江中下游江湖关系的剧烈演变引起了洞庭湖水位的相应变化,并带来了显著的生态环境效应。为了揭示洞庭湖水位变化与水质变化的内在联系和特征,根据洞庭湖区典型水文站1995年-2010年历史水位与水质观测资料,从年内季节和年际时间尺度上,对洞庭湖水位变动情况及其对水质的影响进行了分析。结果表明,所选的洞庭湖区的典型水文站15年来水位总体呈现下降的趋势;在年际变化上,水质指标TN、高锰酸盐指数随着水位的降低而升高;年内季节变化上,TN含量表现出枯水期>平水期>丰水期的特征,而TP含量表现出相反的特性,随着丰水期水位的升高而含量也相对升高。总体上,洞庭湖水位变化与水质状况表现出较强的相关性。     

湖泊防渗对地下水水质影响的数值模拟

为研究湖泊防渗对地下水水质的影响,在现场和室内试验的基础上,运用二维包气带溶质运移模型进行防渗对地下水中氨氮污染物的浓度影响的模拟。分析结果表明：当湖水氨氮浓度保持目前的0.14mg/l时,无防渗时,地下水中氨氮平均浓度由0.43mg/l下降到0.23mg/l,有防渗时,则下降至0.29mg/l;当湖水中氨氮污染物浓度为1mg/l,无防渗时,在计算期末地下水中氨氮平均浓度由0.43mg/l上升到0.77mg/l,有防渗时,则上升至0.53mg/l。因此,在湖水水质好于地下水时,湖底防渗将降低地下水环境质量改善的速度;而在湖水水质较差时,湖泊防渗将显著降低地表水污染物向地下水的扩散强度,有利于地下水水质的稳定。     

哈达山输水工程水质数值模拟研究

Delft-3D是由荷兰水力研究院开发设计的三维可视水动力-水质联合模拟软件系统,可全面仿真水域的三维循环水流水质情况。文章采用解析法预测了哈达山水利枢纽工程输水后输水干渠水质浓度,并以Delft-3d软件为技术平台,建立了哈达山水利枢纽输水工程花道泡反调节水库水质数值模拟模型,预测了输水后花道泡的水位、水质浓度变化趋势。     

基于情景模拟的闽三角城市群承洪适灾网络构建及规划响应策略

为降低洪涝灾害的风险,基于韧性承洪的理念,构建闽三角城市群承洪适灾网络体系。在明晰既有研究不足和学科需求的基础上,阐述了由自然生态适灾系统和社会适灾应急系统两个层面构成的生态-社会适灾网络理论;确立了结合机器学习的洪涝灾害情景推演、结合成本路径计算的绿色基础设施网络构建、结合空间图形分析的疏散通道网络构建、结合定性分析的适灾规划响应策略构建4项核心技术流程。从闽三角城市群生态适灾网络和社会适灾网络的视角出发,划定适灾基底与预警范围;构建基于绿色基础设施网络与疏散通道网络有机结合的“生态-社会”综合适灾网络,并围绕网络构建结果,提出基于网络优化的规划响应策略。本研究丰富了城市群尺度承洪适灾网络的理论框架和构建方法,为实现洪涝灾害韧性防控和交叉学科技术融合提供借鉴与参考。     

太湖流域水质模拟研究

将荷兰Delft水力学研究所研制的Delwaq水质模型应用于太湖流域，通过对太湖流域水质模拟研究，进行模型参数的率定和验证以及灵敏度分析，得到了适合太湖流域平原河网的水质模型和参数，其模型计算值和实测值批合较好。     

长江口污水超标排放对水质影响的数值模拟研究

为分析长江口污水超标排放对水质的影响,建立了包括溶解氧(DO)、生化需氧量(BOD)、氨氮(NH_3-N)和磷酸盐(PO_4~(3-)-P)等水质指标的长江口杭州湾水动力水质数学模型,并对长江口污水超标排放过程进行了模拟。计算结果表明:长江口的水动力条件有利于污染物的稀释扩散,对短期超标排放(如24 h)的污水,可以在短时间内稀释并使海域水环境恢复至正常水平;对于长期超标排放,污染物质的累积作用将会对整个海域水质产生不利影响,使水质下降。     

基于数值模拟对深埋引水隧洞地震响应研究

以某城市某项目引水隧洞为研究对象,以构建的深埋引水隧洞的地震响应进行数值模拟研究为基础,通过控制变量,分析不同条件下岩体的力学特性,建立其本构关系模型。同时,分析模型情况,并在动静荷载作用下研究其岩体的具体破坏情况。结果表明,通过建立数值模拟本构关系模型,其本构关系曲线主要为直线弹性-脆性下降-理想状态3个阶段,同时考虑以应变、围压以及破坏效应为主要基础。引水隧洞经受地震条件作用时,响应过程与深埋应力结构具有差异。通过分析静动条件下引水隧洞地震响应情况,从不同轴压、围压条件以及峰值、荷载作用时间4个变量对引水隧洞的地震响应情况进行探讨。应力状况会随着轴压变大而变大,随着围压变大而变小。并且当荷载作用时间不变时,峰值荷载越小,其应力越小;当地震峰值荷载不变时,荷载作用时间越长,其应力越大。     

深圳河湾水质数值模拟研究

基于EFDC模型和WASP模型建立了深圳河湾水动力和水质模型,采用2011年实测数据对模型进行率定和验证,结果表明,计算值与实测值吻合较好,丰枯季高低潮位平均误差小于0.20 m,DO、BOD5平均误差小于20%,TN、TP和Chl a(叶绿素a)平均误差小于30%。在此基础上进行案例研究,研究结果表明,氮、磷营养盐负荷削减80%对藻类生长的影响不明显;削减95%负荷时,Chl a浓度下降40%。     

茂名港规划水质数值模拟

根据规划安排,茂名港将新建博贺新港和吉达港,该文针对茂名港建立二维水动力-水质模型模拟茂名港海域的水动力条件变化情况,并以石油类为模拟因子,对排污口正常排放与事故排放条件下水质进行模拟。结果表明,在正常排污情况下不会对各敏感保护目标水质产生不利影响,而在事故排放条件下该海域水质将出现超标现象。     

Application of Improved Comprehensive Water Quality Marking Index Method in Water Quality Evaluation of Pearl River EstuaryEI北大核心CSCD

To study the characteristics of water quality variation in the Pearl River Estuary during the recent years, the water quality in the Pearl River Estuary is evaluated and the tempo-spatial distribution characteristics of water quality is analyzed, based on data from 51 monthly collected water quality sampling points from 2018 to 2020, with evaluation indices filtered using principal factor analysis and improvement on traditional comprehensive water quality identification index method using combinatorial integration method.Results show that the comprehensive water quality identification index method combined with combinatorial integration method takes both excessive pollutants index and other indices into account, so as to obtain reasonable and reliable results, which means the method is suitable for large-scale watershed water quality assessment. The water qualities in all drainages tend to improve over the years, mainly from class of inferior Ⅴ to Ⅲ, which met the water quality goals in water environment function zones. The water quality in the western regions was slightly worse than that in the eastern regions.The river water quality in the Nanshan district was better than that in the Dakonggang district, however the improvement in river water quality in Dakonggang and Qianhai district was more significant. The water quality of the upstream was generally better than that of the downstream. Estuary water quality fluctuates greatly with the seasons, which was generally affected by sea water pollution and the tidal sluice operations. © 2022, Editorial Board of Water Resources Protection. All rights reserved.     

闽江下游水质变化趋势分析

根据闽江水口水库运行以来1993—2011年闽江下游省控监测断面的主要水质数据,应用季节性肯达尔检验法对省控断面的水质指标变化趋势进行分析,并应用偏相关分析法对竹岐、魁岐断面的夏秋季(6—11月)DO降低的原因进行分析。结果表明:近十几年来,闽江下游水质总体较好,上段水口水库和下段的入海口河道水质变化不大,但邻近人口聚集地的河道水质状况呈下降趋势,其中竹岐、魁岐断面的夏秋季DO降低最为明显;竹岐和魁岐断面的夏秋季DO分别与竹岐断面径流量成极显著性正相关,偏相关系数分别为0.749和0.866,分别与福州市GDP成极显著性负相关,偏相关系数分别为-0.739和-0.875。     

七格污水处理厂改造对钱塘江水质的影响研究

为分析七格污水处理厂提标改造对钱塘江河口水质的改善情况,利用MIKE21建立了钱塘江河口闸口至盐官的平面二维潮流和水质模拟分析模型。模型验证后,选取90%保证率枯水年的实测河道地形和大潮期实测潮位过程,分析了七格污水处理厂提标改造工程对钱塘江河口水质变化的影响。结果表明:七格污水处理厂提标改造后,钱塘江河口NH3-N劣于Ⅱ,Ⅲ,Ⅳ类限值的最大影响范围分别减少了约22%,89%和50%,最大值和平均值分别降低了约21%和10%;TP劣于Ⅱ,Ⅲ,Ⅳ类限值的最大影响范围分别减少了约19%,85%和33%,最大值和平均值分别降低了约22%和7%;而CODMn劣于Ⅱ,Ⅲ,Ⅳ类限值的最大影响范围分别减少了约84%,0%和0%,最大值和平均值分别降低了约7%和3%。七格污水处理厂的提标改造可有效削减排入钱塘江的污染物总量。     

Numerical simulation of water quality in Yangtze Estuary

In order to monitor water quality in the Yangtze Estuary, water samples were collected and field observation of current and velocity stratification was carried out using a shipboard acoustic Doppler current profiler (ADCP). Results of two representative variables, the temporal and spatial variation of new point source sewage discharge as manifested by chemical oxygen demand (COD) and the initial water quality distribution as manifested by dissolved oxygen (DO), were obtained by application of the Environmental Fluid Dynamics Code (EFDC) with solutions for hydrodynamics during tides. The numerical results were compared with field data, and the field data provided verification of numerical application: this numerical model is an effective tool for water quality simulation. For point source discharge, COD concentration was simulated with an initial value in the river of zero. The simulated increments and distribution of COD in the water show acceptable agreement with field data. The concentration of DO is much higher in the North Branch than in the South Branch due to consumption of oxygen in the South Branch resulting from discharge of sewage from Shanghai. The DO concentration is greater in the surface layer than in the bottom layer. The DO concentration is low in areas with a depth of less than 20 m, and high in areas between the 20-m and 30-m isobaths. It is concluded that the numerical model is valuable in simulation of water quality in the case of specific point source pollutant discharge. The EFDC model is also of satisfactory accuracy in water quality simulation of the Yangtze Estuary.     

基于SOM和 PCA的闽江流域地表水水质综合评价

根据2014年1月至2015年11月闽江流域19个断面的水质月均值监测数据,采用自组织特征映射网络(SOM)和主成分分析(PCA)法研究了闽江流域水质时空变化特征,并用水质指数对闽江水质进行了综合评价。SOM分析将水质样本分为3个空间群组,其中水质变化周期分2个阶段:4—11月、12月至次年3月。PCA法分析表明,春冬季沙溪和富屯溪支流以及闽江下游福州城区河段营养盐水平偏高,在春夏季上游部分河段和下游闽江口有机污染水平偏高。水质指数评价结果显示,闽江流域整体水质较好,其中三大子流域及闽江下游水质评价从优至劣顺序为:富屯溪流域、建溪流域、沙溪流域、闽江下游流域。     

Numerical study of water age influenced by tide and runoff in Daliaohe Estuary in China

Based on the concept of the age, the water transport characteristics as the response to the runoff and the tide in Daliaohe Estuary in China are studied under different hydrodynamic conditions using a three-dimensional convection-diffusion model. The results show that the relationship between the average age at a specific position and the runoff could be expressed by a power function approximately. In the river channel, the runoff controls the water transport: it might take about 52 d, 27 d and 15 d for the water parcel to be transported from Sanchahe to the mouth during the dry, normal and rainy seasons, respectively. Outside the mouth, the tide is dominant even though the difference between the spring tide and the neap tide is less than 5 d, and the water parcel transports mainly along the northwest direction through the West Waterway and the southeast direction through the East Waterway. A significant age stratification emerges in the vicinity of the mouth, in which there exists a strong interaction between the tide and the runoff, and the age differences between the surface and the bottom could reach 7 d.     

长江口风暴潮流场计算

利用一、二维数学模型，并考虑长江口深水航道治理工程的进展情况，对长江口区风暴潮流场进行了数值模拟计算。计算结果表明，治理工程对风暴潮引起的增长影响不显著，风暴潮增水期间潮位升高，涨、落潮流速及长江口北槽的分流会增大。     

长江口近十年水质时空演变趋势分析

为了掌握长江口水质污染变化情况,在长江口徐六泾、石洞口、启东港、南港、北港和吴淞口下23公里处6个监测断面,对TN、TP浓度进行了为期13 a的常规监测。监测结果表明:(1)2010年以前,6个监测断面的营养盐浓度年内波动起伏较大,2010年以后进入相对平稳阶段,并呈现逐年下降的趋势。说明自水资源"三条红线"监管制度和区域内各治理项目实施以来,取得了较大的正效应,TN和TP都呈现了年内变幅减小、浓度逐年降低的趋势。(2)由于河口受潮汐影响,各个断面的TN和TP均出现不同程度的丰水期营养盐浓度高于枯水期的情况,并且呈现出丰枯两季营养盐浓度差异逐渐减小的趋势。(3)2009年枯水期为TN沿程变化的分界点,即徐六泾-南港的上升趋势、南港-北港的下降趋势,在2009年之后变为徐六泾-南港的下降趋势,南港-北港的上升趋势。TP的丰枯沿程变化则比较平稳,但有小幅度上升趋势。     

松花江干流水质模型在流域水资源保护管理中的应用

在讨论松花江流域水资源保护管理工作的基础上,运用降雨径流模型、水动力学模型、污染物传输扩散模型耦合的松花江干流水质模型,并以2005年水污染事件数据进行验证。结果表明:模型能够准确地模拟流域水量、水质变化,模拟值准确率较高。随后进行了水功能区管理、入河排污口监督管理、日常水质模拟等水资源保护管理中的应用研究。计算结果表明:分别实施污染物排放量削减10%的方案及大中城市污水处理率不低于70%的方案后,全年河流水质污染物平均值较之前将分别下降0.16和1.53mg/L,下降比例分别为2.8%和27.3%。如距雅鲁河河口45.4km处需建入河排污口,则其排放应达到国家综合排放二级标准;库容6.08亿m3的哈达山水利枢纽建成后,在流量减少66m3/s的情况下,对第二松花江丰满坝下至库末段、库区下游河道水质进行模拟预测,结果满足水质目标要求。