浅析闲林水库在千岛湖引水工程中的地位与作用

结合千岛湖引水工程实例,本文论证了在长距离大流量引水工程中设置调节水库的必要性。对工程沿线潜在调节水库,从地理位置、库容、水质和水位等方面进行了分析比较,得出闲林水库是引水工程的最优调节水库,并阐述了闲林水库作为调节水库在千岛湖引水工程中的不可替代地位与若干作用。     

鄱阳湖水利枢纽工程对水质环境影响研究

鄱阳湖水利枢纽工程的建设,将改变湖内水动力特性,进而影响鄱阳湖的水环境质量。采用水深平均的二维水动力-水质模型对鄱阳湖现状水动力和水质进行模拟验证,水陆边界模拟采用动边界技术,摸拟"高水湖相,低水河相"的湖泊水域变化特征,水质特性为枯水期水质较差,丰水期水质较好,靠近入湖河口的湖区劣于湖心水质,北部出湖水质较好的现状。模型模拟预测在现状外部入流边界和现状污染负荷条件下,3种不同运行方式下,鄱阳湖湖流的时空形态相应发生的变化和相应水质变化。计算结果表明,枯水期大部分区域的水质浓度下降,但尾闾等部分区域有所升高,开闸泄水期前后,水质较现状水质下降,敞泄期的大部分时间,较现状水质基本相似,蓄水期水质变化不大。水动力特性综合水质浓度的改变,增加了局部水体的富营养化风险。研究结果可为枢纽的建设提供科学依据。     

Resurrection of the Lake Michigan Eutrophication Model,MICH1

The Lake Michigan model, MICH1, was developed more than 30 years ago. This framework was evaluated using field data collected in 1976 and was later applied to predict total phosphorus and phytoplankton concentrations in Lake Michigan during the 1980s and early 1990s. With a renewed interest in the interaction of phytoplankton with toxics and the applicability to Total Maximum Daily Load studies, several new models have been developed and older models have been revived. As part of our interest in plankton dynamics in Lake Michigan, the MICH1 model was resurrected. The model was evaluated over the 1976–1995 period, with a surprisingly good model fit to lake-wide average total phosphorus (TP) field data. However, the model was less successful in mimicking the chlorophyll-a measurements, especially in the hypolimnion. Given the results, the model was applied to perform a few long-term TP model simulations. Using the model with average 1994–95 phosphorus loadings, a steady state was reached within approximately 20 years, and the lakewide phosphorus concentration was below the International Joint Commission water quality guideline of 7 μg/L. This exercise demonstrated that a relatively simple, four-segment model was able to mimic the TP lake-wide data well. However, this model was less suitable to predict future chlorophyll-a concentrations due to the limitation in the representation of the foodchain and the difficulty of the coarse segmentation of the model to capture the deep chlorophyll-a layer. Strengths and limitations of this model can guide future development of eutrophication models for Lake Michigan and the other Great Lakes.     

Integration of Hydraulic and Water Quality Modelling in Distribution Networks: EPANET-PMX

Simulation models for water distribution networks are used routinely for many purposes. Some examples are planning, design, monitoring and control. However, under conditions of low pressure, the conventional models that employ demand-driven analysis often provide misleading results. On the other hand, almost all the models that employ pressure-driven analysis do not perform dynamic and/or water quality simulations seamlessly. Typically, they exclude key elements such as pumps, control devices and tanks. EPANET-PDX is a pressure-driven extension of the EPANET 2 simulation model that preserved the capabilities of EPANET 2 including water quality modelling. However, it cannot simulate multiple chemical substances at once. The single-species approach to water quality modelling is inefficient and somewhat unrealistic. The reason is that different chemical substances may co-exist in water distribution networks. This article proposes a fully integrated network analysis model (EPANET-PMX) (pressure-dependent multi-species extension) that addresses these weaknesses. The model performs both steady state and dynamic simulations. It is applicable to any network with various combinations of chemical reactions and reaction kinetics. Examples that demonstrate its effectiveness are included.     

Perchlorate in environmental waters of the Laurentian Great Lakes watershed: Evidence for uneven loading

A database of nearly 500 analyses of perchlorate in water samples from the Laurentian Great Lakes (LGL) watershed is presented, including samples from streams, from the Great Lakes and their connecting waters, with a special emphasis on Lake Erie. These data were assessed to test an earlier hypothesis that loading of perchlorate to the LGL watershed is relatively uniform. Higher perchlorate concentrations in streams in more developed and urban areas appear to indicate higher rates of loading from anthropogenic sources in these areas. Variable perchlorate concentrations in samples from Lake Erie indicate transient (un-mixed) conditions, and suggest loss by microbial degradation, focused in the central basin of that lake. Interpretation of the data included estimation of annual loading by streams in various sub-watersheds, and simulations (steady state and transient state) of the mass balance of perchlorate in the Great Lakes. The results suggest uneven loading from atmospheric deposition and other sources.     

永定河园博园水源净化工程地基承载力检测及评定

在工程建设中．经常要遇到需要加固的软弱地基。地基检测作为建筑物地基的质量关对工程施工有着重要作用,是隐蔽工程验收的重要组成部分。在对永定河园博园水源净化工程施工第二标段强夯处理地基的施工质量检测中,为了较为准确检测本工程的地基处理效果,采取了平板载荷试验与动力触探相结合的方法来评价地基的承载力。平板载荷试验能够准确反映地基承载力,而动力触探试验能够较为全面反映整个工程现场的土层处理状况。通过2种方法的结合运用和综合判断,得出地基承栽力符合设计要求的结论。对于强夯处理地基的承载力检测,这种方法不仅快速高效,而且结论可靠。     

水网连通对大东湖富营养化的影响

为定量评价水网连通对湖泊富营养化的影响,以武汉大东湖水网连通为研究对象,构建大东湖水网水生态环境数学模型,在模拟分析水网连通前后COD、TN、TP、Chl-a等富营养化评价指标变化的基础上,进一步计算和评价水网连通对各湖泊综合营养状态指数、营养状态的影响。计算结果表明:水网连通后,杨春湖、沙湖、北湖水质改善,藻类生物量减少,水体富营养程度降低;东湖、严西湖水质有一定恶化,藻类生物量增加,水体富营养程度升高;水网连通对湖泊富营养化的影响较复杂,且存在污染风险。研究成果可为水网连通工程的管理运行提供参考依据。     

大通湖区水系连通工程改善水环境的效果评估

大通湖是洞庭湖区的重要组成部分,近年其水质状况呈现恶化态势,正通过实施水系连通工程,以期改善其水环境。基于MIKE21构建大通湖区水系连通工程的二维水动力-水质数学模型,选取总氮和总磷作为水质指标,模拟不同连通调度方案下大通湖的氮磷浓度变化,采用滞水区面积比例、浓度变化指数、换水率和水质浓度改善率,评估6个连通方案下大通湖水环境的改善效果。结果表明:通过实施引水调度方案能够有效改善大通湖水环境,当引水前期流量取30 m~3/s,出口水位控制在25.48 m时和引水后期流量保持为30 m~3/s不变,出口水位调整至25.88 m时,大通湖水环境改善效果最佳。本研究可为实施水系连通工程,改善类似湖泊水环境和提高引水调度效率提供参考。     

Spatio‐temporal variations in the trophic status of Lake Naivasha,Kenya

The spatio‐temporal dynamics of the trophic state of a lake are crucial in defining its water quality, as well as biodiversity. Accordingly, this study focused on the spatio‐temporal variations of the trophic state, and the possible causes of the heterogeneous turbidity in Lake Naivasha, Kenya. The trophic state of the lake oscillated between a eutrophic and hypereutrophic condition, being found to be more eutrophic than reported in previous studies, indicating a progressive deterioration of its water quality. Inferences from the graphical representation of the deviations of total phosphorus and Secchi depth from the chlorophyll‐a trophic state indices revealed that the lake is predominantly phosphorus limited. Furthermore, the turbidity in the northern part of the lake is dominated by suspended sediment and dissolved coloured material. Discriminant analysis resulted in identification of three distinct trophic state regions in Lake Naivasha, namely the northern region, the mid and southern part and the more or less isolated Crescent Lake. The results of this study provide a good basis for further investigation of the current loading magnitude of both nutrients and sediments, in order to facilitate sustainable management to ensure community integrity and ecosystem functions of the lake.     

Optimal Operation of Artificial Groundwater Recharge Systems Considering Water Quality Transformations

In water limited areas as water demand increases alternative sustainable water sources must be identified. One supply augmentation practice, that is already being applied in the arid southwest U.S., is artificial groundwater recharge usingwastewater effluent. The objective of a recharge facility is to supplement the available groundwater resources by storing water for the future. The resulting reclaimed water is used primarily for non-potable purposes but under increasing stressesshifting to potable use is likely to happen. Water quality thenbecomes a more pressing concern. Water quality improvements during infiltration and groundwater transport are significant and are collectively described as soil-aquifer treatment (SAT). To meet user needs, the recharge operation must be efficiently managed considering monetary, water quality and environmental concerns. In this paper, a SAT management model is developed that considers all of these concerns. Within the SAT management model, the shuffled complex evolution algorithm (SCE) is used as the optimization tool. SCEis a relatively new meta-heuristic search technique for continuousproblems that has been used extensively for hydrologic model calibration. In this application, SCE is integrated with the simulation models (MODFLOW, MT3D, and MODPATH) to represent movement and quality transformations. Two steady state case studies on a general hypothetical aquifer (modeled after a field site) were examined using the management model.     

鄱阳湖水利枢纽工程关键技术研究

本文针对鄱阳湖水利枢纽工程修建后将发挥的作用和可能产生的影响,采用现场调研、实测资料分析和数学模型计算等研究手段,从鄱阳湖流域水资源演变趋势及开发利用状况,三峡水库运用对长江中下游河道冲淤变化及江湖关系的影响,枢纽工程对水资源、防洪、湖区水环境和鱼类的影响,枢纽工程合适的下闸蓄水时期和蓄水位,工程闸门型式及鱼道建设等方面进行了研究,试图为鄱阳湖水利枢纽工程项目立项和规划设计提供科技支撑。     

Feasibility Assessment of Data-Driven Models in Predicting Pollution Trends of Omerli Lake,Turkey

Data-driven models are commonly used in a wide range of disciplines, including environmental engineering. To analyze Omerli Lake’s historic water pollution status, this study monitors data for dissolved oxygen, 5-day biochemical oxygen demand, ammonium nitrogen, nitrite nitrogen, nitrate nitrogen, and ortho phosphate. The quality of the lake water is assessed based on measurements of dissolved oxygen. The collected data are analyzed using regression analysis and artificial neural network models. The main goal of this paper is to reveal the best applicable data-driven model in order to gain forward-looking information regarding the dissolved oxygen level of the lake using other pollution parameters. In order to ascertain eutrophic status, total phosphorus loads for each year are represented on a Vollenweider diagram. Results designate an increasing risk of eutrophication for Omerli Lake in recent years. Results of the data-driven models show that the artificial neural networks model constitutes the best relationship between the dissolved oxygen and other parameters.     

引江济太工程水源地河床稳定性分析

引江济太工程水源地位于长江澄通段的福山倒套内,其河床稳定性是影响引江济太工程成败的关键。因此,根据大量实测水下地形资料,对福山倒套的河势演变进行分析,研究倒套河床形态特征对自身水动力结构的影响。同时,结合二维水量模型对福山倒套淤积的形势进行数值模拟和预测。结果表明:①倒套内部水位降低,但变化不明显;②倒套内部流场流速整体下降,尤其是倒套口门处流速值减小较大;③倒套虽然处于淤积阶段,但倒套口门段较为稳定。因此,适时疏浚上部串沟是维持倒套稳定之关键。     

遗传算法与投影寻踪模型在湿地水质综合评价中的应用

参考地表水环境质量标准和湖库营养状态评价标准,采用基于遗传算法的投影寻踪模型,计算反映湿地水体质量状况和湿地营养状态的一维投影值,直观地反映湿地水环境质量。将此方法在河北衡水湖湿地进行了实例应用,结果表明,衡水湖湿地2010年水质属于Ⅱ类,处于中度富营养状态。     

太湖调水工程对水环境改善的战略意义

根据太湖流域引清工作实践 ,阐述了调水工程对改善水环境的作用。同时提出了对引水工程的思考 :应开展引清对下游河道水质的影响评价工作 ;开展点面结合的环境水利规划 ;引清与农业节水相结合 ,可进一步增加区域内的环境效益。     

大东湖水网连通的水动力与水环境变化响应

为揭示城市河湖水网连通工程的生态水文响应机制,以武汉大东湖水网连通工程中东湖-沙湖连通为例,建立水动力-水质耦合数学模型,模拟分析水网连通前后东湖、沙湖的水动力与水质变化,并从空间分布和时间变化两方面,分析水质变化与水动力变化的响应关系。结果表明:东湖-沙湖连通后,东湖与沙湖水动力条件改善较明显,TN浓度和TP浓度基本呈现下降的变化趋势;主流线附近水域流速增加,TN、TP浓度降低,水质改善效果较好;偏离主流线较远的水域,其流速、TN、TP浓度均变化不大;东湖子湖(汤菱湖、水果湖)、沙湖的TN、TP浓度变化过程与流速变化过程呈现负相关关系。     

Management Options to Improve Water Quality in Lake Peipsi: Insights from Large Scale Models and Remote Sensing

Nutrient pollution causes frequent blooms of potentially harmful cyanobacteria in Lake Peipsi (Estonia/Russia). Although external nutrient loading has reduced since the 1990s, lake water quality has barely improved, and eutrophication is still considered a threat to lake biota and water usage. To understand the recovery dynamics of the lake it is necessary to analyse the effects of land use and lake management on water quality to develop mitigation strategies. Comprehensive analysis has thus far failed due to information gaps inherent to conventional monitoring strategies. We show how two large-scale hydrological models using Earth observation data provide spatial information on pollution and can help explain the causes of past and current lake eutrophication. WaterGAP3.2 provides valid estimates of present and probable future phosphorus concentration in the lake water, based on past hydrological conditions. WaterWorld models spatial potential water quality and a scenario of optimal pollution reduction. Remotely sensed optical water quality data can be used to analyse recent, spatial water quality dynamics. The spatial and temporal algae distributions and can help explain eutrophication causes at Lake Peipsi and its catchment, adding value to in situ monitoring and supporting river basin management with large scale data.

     

太湖自动监测站水质分析及影响评价

近年来,太湖流域的水污染问题受到极大的关注,水量水质监测站在监控和改善太湖流域的水环境中起着举足轻重的作用。介绍了太湖流域水质自动监测站的建设情况,分析了2008年引江济太期间常熟等5个自动监测站的监测数据,并对监测站的重要性进行详细的分析和评价。由监测数据得知,5个自动监测站水质总体上有所改善。为进一步改善太湖流域的水质,建议加大监测站的建设和优化力度,加强监测站之间和监测站与水量控制单位的联动性。     

无锡水源地贡湖引水改善水质效果分析

为了分析“引江济太工程”对无锡市主要饮水水源地贡湖南泉水质的影响,建立了太湖二维水量水质模拟模型。在设定引水水质与水源地水质的条件下,针对常规和突发污染事故调度情况,模拟分析了引水枢纽望亭立交及梅梁湖泵站不同引水流量对南泉水源地水质的影响,掌握了水源地水质的恢复时间及恢复过程与引水流量的关系。研究结果可为水资源管理部门决策、优化工程调度、水源地供水安全保障提供科技支撑。     

武汉大东湖水网构建工程对生物多样性影响研究

由于江湖通道隔截,武汉大东湖各湖泊变得相对“孤立”,水质污染严重,生物多样性明显下降,为此,武汉市实施了大东湖水网构建工程,将长江与大东湖各湖泊连通起来。根据大东湖目前的污染现状、工程引水规划以及长江和东湖的水质和水生生物情况,分析了工程实施对湖泊生境、水生生物、鱼类及鸟类的影响。工程的实施,将增强水体的流动性、提高湖泊的水体置换能力、减少死水区、扩大湖泊环境容量,为水生生物多样性的恢复创造适宜的生境。