墨水湖N/P水质模型研究

武汉墨水湖30多年来因湖周大量城市污水的排入,造成湖泊严重富营养化,急需综合规划治理,因此需研究墨水湖水体污染变化规律,开展水质模型的研究。针对墨水湖水文、水质、地貌状况,把整个湖区划分五块（子湖区）,建立分散结构N/P水质模型,提出了一套可行的模型参数识别方法,并作了模拟检验,精度令人满意。在分析中运用系统论方法,并应用计算机现编程序操作。     

湖泊水质遥感的几个关键问题

我国目前约有面积大于1km2的湖泊有3000个,绝大部分属高叶绿素和高悬浮物浓度水体,属于典型的Ⅱ类水体,物质组成多样,水体的光学辐射传输复杂,且有大范围的光学浅水.我国的湖泊水质/水色遥感虽然取得了一定进展,但借鉴海洋水色遥感的相关理论和经验,还需要解决以下四个关键问题:1)兼顾海洋沿海水质遥感,发展专用的静止卫星湖泊水质遥感器;2)在当前多光谱遥感资料基础上研发高光谱湖泊水质因子提取的遥感定量化模型,提高反演精度;3)深化湖底底质对湖泊水质/水质遥感影响研究,发展湖底水质遥感反射率精确计算模型;4)发展适用于湖泊水体区域性Ⅱ类水体大气校正方法,并集成反演、遥感产品制作、分发等技术,构建湖泊水体水质/水色业务化运行体系.     

基于改善水质的浅水湖泊引调水模式的评价指标

以浅水湖泊引清调水的目的为基础,结合生态水力学要求,兼考虑经济性因子,尝试性地建立了浅水湖泊调水方案评价指标体系.评价指标包括湖泊水质改善效果指标、水力条件指标和经济效益指标.以玄武湖调水模式为例,采用二维水质水量模型对玄武湖不同的引水规模、引水方式、引水口和出水口流量分配的引调水方案进行模拟计算,统计出各个评价指标的结果,综合分析评价出相对最优的引调水方案.该评价方法可推广到其它类似的浅水湖泊引清调水模式的评价中.     

云贵高原湖泊水质现状及演变

利用2008年云贵高原13个湖泊丰水期的全面水质调查数据,系统分析云贵高原湖泊水质现状,通过与历史资料对比,揭示20年来的水质变化,并分析水质变化的原因.同时利用主成分分析将23个水质参数概括为6个主要成分,除程海外所有湖泊水质均与第一主成分密切相关.人类活动影响下的水体富营养化、有机污染以及农业面源污染等是除程海外湖泊污染的主要驱动因子,程海水质变化主要受水体的矿化度增加所驱动.另外,根据各主成分得分,本文也对13个湖泊水质进行了综合评价,并在评价的基础上就湖泊的保护和治理提出建议.     

浅水湖泊生态系统恢复的理论与实践思考

随着我国湖泊生态环境越来越严峻,湖泊生态恢复也逐渐被人们所重视．实际上,湖泊生态恢复应该是一项系统工程、是通过一定程度地减缓或改善环境压力,结合某种或多种水生生物的种养措施,逐步使得生态系统向良性的或者是被改变前的状态发展,目前．湖泊生态恢复不是被单纯地理解为种草、养鱼等,就是被解释为生物群落的人为搭配或镶嵌．由于这种认识上的偏差,导致湖泊治理中有关生态修复的实践长期以来鲜有成功的实例．最后、以太湖为例,给出了湖泊局部水体生态修复达致净化水质的技术思路——通过改善环境来恢复水生植物,通过水生植物恢复来引导乍态系统向草型湖泊转变,通过水生系统恢复达到改善水质的目的．这种思路能否成功用于指导湖泊水生植物与生态系统恢复、还有待于进一步实践的检验．     

大型浅水湖泊富营养化国际研讨会在南京举行

2005年4月24日至26日,大型浅水湖泊富营养化国际研讨会在南京顺利召开.包括国际理论与应用湖沼学会执行副主席Brian Moss教授、《Ecological Modelling》主编S.E.J φrgensen教授、《Ecological Engi- neering》主编Williams Mitsch教授等来自美、德、奥、丹、荷等20余国的代表约200人出席了会议.大会共收到论文136篇.大会邀请了三位教授作了大会主题发言,分别是刘正文教授(太湖生态环境状况)、Brian Moss教授(湖泊生态修复的发展现状)和Williams Mitsch教授(湿地与浅水湖泊的模拟与管理)会议按五个主题进行专题交流,大会报告有:(1)湖泊物理过程及其生态环境效应:David Hamilton(物理要素对蓝藻     

水质较好湖泊环境保护的理论基础及中国实践

目前,我国湖泊富营养化及蓝藻水华问题十分突出,国家高度重视湖泊的生态环境保护.自“九五”以来,国家就投入太湖、巢湖、滇池“老三湖”等重污染湖泊的治理,但成本巨大,且历经近30年才初见成效.按照湖泊污染程度,湖泊治理与保护可分为“污染治理型”“防治结合型”“生态保育型”3大类.“老三湖”的治理是典型的“先污染、后治理”的模式,水质较好湖泊主要属于生态保育型湖泊,因此,“老三湖”治理模式不适用于水质较好湖泊的保护.本文系统总结了我国水质较好湖泊优先保护理念的形成和水质较好湖泊专项实施的历程.根据水质较好湖泊的特点,及其生态系统退化与修复的一般过程,提出了水质较好湖泊保护的基本思路.从热力学角度,阐明了氮磷营养盐输入湖泊生态系统中是熵增过程,也是湖泊生态系统退化的根本原因,湖泊氮磷污染负荷源头控制是关键.湖泊流域生态安全格局是确保湖泊生态系统健康的基础,从景观生态学角度,阐明了优化湖泊流域水土资源利用、优化发展模式是减轻湖泊环境压力的重要途径.在浅水湖泊生态系统,以沉水植物占优势的“清水态”和以浮游植物占优势的“浊水态”转换过程不是沿着同一条途径,存在上临界阈值和下临界阈值,水生态修复过程表现出一种迟滞的现象.从湖泊水生态系统稳态转换理论角度,阐明了湖泊生态修复工程应在湖泊生态系统发生退化转变之前实施,才能获得较高的环境效益.通过国家财政专项对81个水质较好湖泊的支持,既能促进湖泊流域经济社会发展,又能确保湖泊水环境质量变好,湖泊水生态系统逐步改善.建议加强不同类型湖泊保护模式的总结,深入对水质较好湖泊生态系统演替理论和保护技术研究,支撑国家系统开展水质较好湖泊保护.     

富营养化浅水湖泊藻源性湖泛的短期数值预报方法——以太湖为例

本文建立了一种富营养化浅水湖泊藻源性湖泛的短期数值预报方法.选取表征藻源性湖泛的代表性指标叶绿素a和溶解氧浓度作为预测变量,以天气预报中的风场为驱动力,求解浅水湖泊三维水动力水质耦合数值模型,计算未来3 d浅水湖泊叶绿素a和溶解氧浓度的时空分布,然后结合未来3 d的气象因子信息建立经验公式,计算湖泛易发水域发生湖泛的概率,并进一步确定湖泛发生位置和面积.以太湖为例,采用构建的方法于2013 2014年夏、秋季对太湖7段湖泛易发水域的湖泛发生概率及发生面积进行未来3 d的预测预报,预报正确率在80%以上.     

浅水湖泊湖沼学与太湖富营养化控制研究

自2007年无锡暴发饮用水危机事件以来,太湖经历了前所未有的高强度、大规模治理,各种治理措施累计投资已经超过千亿元.监测显示,在治理初期太湖的氮、磷浓度下降明显,水质有所好转,但最近几年关键水质指标总磷与浮游植物叶绿素α浓度出现了波动,蓝藻水华有所反弹.研究表明,太湖的外源负荷并没有减少,这与城镇用水量增加、污水排放标准偏低、面源污染削减不足有很大的关系;同时,内源负荷也因为蓝藻水华的持续而加重,浅水湖泊水深浅、扰动强的特点强化了磷的循环利用效率,加剧了内源负荷对湖泊富营养化和蓝藻水华的影响.气候变暖叠加营养盐富集的复合效应、流域风速下降以及暴雨事件频次和强度增加等气象水文条件变化,都促进了太湖蓝藻水华的暴发;蓝藻水华的时空分布特征则受湖泊水动力的决定性影响.太湖治理的曲折过程,凸显了大型浅水湖泊湖沼学研究的不断深入与发展,未来需要继续加强多学科交叉研究,特别是基于湖泊-流域系统的气象水文、生物地球化学和生物生态学的学科交叉.对于太湖生态环境的综合治理和管理,既要注重湖泊与流域相结合,更需要重视自然科学和人文科学的有机融合,才能真正达到控制太湖富营养化、维护流域水环境安全与社会经济可持...     

镧改性膨润土对浅水湖泊水体磷浓度和沉积物磷形态的影响

分析湖泊沉积物磷形态的变化是揭示控制沉积物磷释放机理的关键.本研究分析了暨南大学南湖加镧改性膨润土前后水体磷浓度和沉积物磷形态变化,以探讨镧改性膨润土对削减水体磷浓度的效果.结果显示,镧改性膨润土添加后,上覆水磷浓度波动较大,总体呈下降趋势;至60 d时,水体总磷、颗粒态磷、总溶解磷和溶解性反应磷分别比添加前下降了45.1%、44.1%、48.2%和85.3%;沉积物中的弱结合态磷和氧化还原敏感性磷含量减少,更稳定的磷灰石结合态磷和残渣磷含量增加,而金属氧化物磷和有机磷含量变化较小.本研究表明镧改性膨润土能改变沉积物磷形态,使活性磷转化为稳定的磷形态,从而提高沉积物对磷的滞留能力、降低湖水磷含量,改善水质.     

A coupled physical-biochemical lake model for forecasting water quality

A new one-dimensional numerical model that includes physical and biochemical processes has been developed. The biochemical processes, influenced by the lake dynamics, are required for forecasting water quality. The model is used to investigate the effects of different internal restoration measures, such as artificial mixing, input of oxygen and drainage of deep water.The model is applied to the Northern Basin of Lake Lugano, a Swiss-Italian border lake. The lake is highly eutrophic and chemically stratified throughout the year. The model was calibrated over one year and validated over a period of several years. The results agree well with the measured data. The coupled model reproduces the observed depth dependency of conductivity even during long simulation times. Due to the predominant mixing, decoupled physical models cannot maintain such gradients. The forecasting capabilities of the model are demonstrated for different case studies. The impact of restoration measures on water quality is rather small. Best results are achieved by reducing the external nutrient loading. Caution is recommended for internal measures as these have to be studied in greater detail.     

The importance of aquatic macrophytes in a eutrophic tropical shallow lake

Inlay Lake is the second largest natural lake in Myanmar. Located in Shan State, in the eastern part of the country, it is a known biodiversity hotspot. The lake is negatively affected by an increasing local human population and rapid growth in both agriculture and tourism. In recent decades, several studies have listed faunistic and floristic groups in Inlay Lake, but there is still a general lack of knowledge about the aquatic macrophyte and phytoplankton community composition and abundance, and their interactions. To fill this knowledge gap, field surveys of biological and physical and chemical parameters were carried out in the period 2014–2017. They show that Inlay Lake is a shallow, clear water and calcareous lake, with nutrient concentrations indicating mesotrophic-eutrophic conditions. However, close to the shore, nutrient concentrations are generally higher, reflecting pollution from inflowing rivers, shoreline villages and floating gardens. Both the richness and abundance of aquatic macrophytes in Inlay Lake were high, with several species forming extensive stands in most of the lake over the whole survey period. Total phytoplankton and cyanobacterial biomass were low, but cyanobacteria included toxin-producing strains of Microcystis, suggesting that cyanobacterial and total phytoplankton biomass need to be kept low to avoid potentially harmful cyanobacterial blooms. Submerged macrophyte abundance and phytoplankton biomass were inversely correlated in the heavily vegetated northern lake area. Our survey suggests a great importance of the submerged macrophytes to the general water quality and the clear water state in Inlay Lake. Maintaining high macrophyte abundances should therefore be a goal in management strategies, both for Inlay Lake and other lakes in Myanmar. It is highly desirable to include macrophytes and phytoplankton in the lake monitoring in Myanmar.     

Validation of a vegetated filter strip model (VFSMOD)

Vegetated filter strips (VFS) are designed to reduce sediment load and other pollutants into water bodies. However, adaptation of VFS in the field has been limited owing to lack of data about their efficiency and performance under natural field conditions. A number of models are available that simulate sediment transport and trapping in VFS, but there is a general lack of confidence in VFS models owing to limited validation studies and model limitations that prevent correct application of these models under field conditions. The objective of this study is to test and validate a process‐based model (VFSMOD) that simulates sediment trapping in VFS. This model links three submodels: modified Green–Ampt's infiltration, Quadratic overland flow submodel based on kinematic wave approximation and University of Kentucky sediment filtration model. A total of 20 VFS, 2, 5, 10 and 15 m long and with various vegetation covers, were tested under simulated sediment and runoff conditions. The results of these field experiments were used to validate the VFS model. The model requires 25 input parameters distributed over five input files. All input parameters were either measured or calculated using experimental data. The observed sediment trapping efficiencies varied from 65% in the 2‐m long VFS to 92% in the 10‐m long filters. No increase in sediment removal efficiency was observed at higher VFS length. Application of the VFS model to experimental data was satisfactory under the condition that actual flow widths are used in the model instead of the total filter width. Predicted and observed sediment trapping efficiencies and infiltration volume fitted very well, with a coefficient of determination (R²) of 0·9 and 0·95, respectively. Regression analyses revealed that the slope and intercept of the regression lines between predicted versus observed infiltration volume and trapping efficiency were not significantly different than the line of perfect agreement with a slope of 1·0 and intercept of 0·0. Copyright © 2001 John Wiley & Sons, Ltd.     

Microbial and geochemical quality of shallow well water in high-density areas in Mzuzu City in Malawi

In Malawi, shallow wells constitute the most important water sources for domestic purposes. However, increasing human population coupled with poor sanitation and infrastructure is undermining the quality of shallow well water. An assessment of microbial and geochemical quality of shallow well water in high-density areas of Zolozolo, Ching’ambo and Chiputula in Mzuzu City, Northern Malawi, has been carried out. The study aimed at characterising domestic water sources, identifying possible sources of water contamination and determining levels of microbial and chemical contamination. Arc-view GIS was used to map the water sources. A questionnaire survey was carried out to elicit information on characteristics of drinking water sources. Water samples were collected from quasi-randomly selected shallow wells and analysed for microbial and chemical parameters using standard methods. HCA, performed using R-programme, was used to group sampled sites according to their bio-physicochemical characteristics. Compliance of the water with MBS/WHO water quality guidelines was determined. The WQI was computed to turn multifaceted data obtained from laboratory analyses into simple information that is comprehensible and useable by the public to assess overall quality of water at a specific water points. The GW-chart was used to show hydrogeochemical water types from each sampled site. Microbial analysis revealed that water from 96.3% of shallow wells recorded faecal coliforms ranging from 129 to 920 cfu per 100 ml which were significantly higher than the Malawi Standards and WHO thresholds. In general, shallow well water is of low mineralisation (EC range 80–500 μS cm⁻¹), with hydrogeochemical facies dominated by Ca–HCO₃, which evolves to Ca–Cl water type. The shallow well water registered a WQI range of 50.16–66.04%, with a medium WQ rating. This suggested that the water obtained from the shallow wells is unsuitable for direct human consumption. It was observed that 100% of the shallow wells were at risk of pollution from onsite sanitation because of their proximity to sanitary facilities. It was strongly recommended that onsite treatment interventions have to be mobilised and initiated to protect the households from further possible consequences of using the water.     

基于水质-水位二元响应关系推求过水型湖泊适宜生态水位研究

适宜的生态水位能够反映湖区生态系统的多种需求,是湖泊长期稳定健康运转的基本保障.目前湖泊适宜生态水位的推求大多侧重恢复天然水位情势.然而过水型湖泊承担着防洪、供水、航运等多种功能,频繁的人类活动导致湖泊水位情势异常复杂.同时随着社会经济的快速发展,水质恶化对过水型湖泊生态系统造成了较大的负面影响,仅恢复天然水位情势难以反映过水型湖泊的生态需求.因此,在IHA-RVA法的基础上,本文针对过水型湖泊吞吐性强的特点,利用水质-水位二元响应关系系统地提出了一套逐月修正过水型湖泊适宜生态水位阈值,并确定适宜水位变动率的方法.以洪泽湖为应用实例,结果表明:1)根据湖泊水文情势和入湖污染物变化情况,湖泊调度周期可以划分为平水期(1-4月)、泄水期(5-6月)、蓄水前期(7-9月)和蓄水后期(10-12月);2)各时期内,洪泽湖水位和水质呈现较强的相关性,其中平水期、泄水期和蓄水后期水质均随着水位上升而下降,平均Pearson系数达-0.77,仅在蓄水前期水质随水位上升而改善;3)现阶段洪泽湖的自净能力和污染物滞留比例竞争关系激烈,逐月适宜生态水位阈值为:12.92～12.99、12.79～12.99...     

基于集合卡尔曼滤波的湖泊富营养化模型Delft3D-BLOOM数据同化

富营养化模型是进行湖泊水环境质量预测和管理的重要工具,然而模型客观存在的误差一直是应用者关心的重要问题.数据同化作为连接观测数据与数值模型的重要方法,可以有效提高模型的准确性.集合卡尔曼滤波(En KF)是众多数据同化算法中应用最为广泛的一种,可进行非线性系统的数据同化,并能有效降低数据同化的计算量.本研究以太湖作为具体实例,选择Delft3D-BLOOM作为富营养化模型,在数值实验确定En KF集合数为100、观测误差方差为1%、模拟误差方差为10%的基础上分别进行模型状态变量同化以及状态变量与关键参数同步同化.结果显示,仅同化状态变量时,模型预测精度有所增加;同时同化状态变量和关键参数时,可显著提升模型在湖泊水环境质量预测中的精度.该研究为应用集合卡尔曼滤波以提高复杂的湖库富营养化模型模拟精度提供了有效的方法.     

安徽省河流和湖库型饮用水水源地水质评价

饮用水水源地的保护问题是关系国计民生的重大问题,饮用水水源地的水质问题越来越受到社会的关注.运用单因子标准指数法以及卡尔森指数法对安徽省境内91个县级以上的饮用水水源地的水质状况以及31个湖库型水源地富营养化程度进行了综合评价,并提出相应的防护措施.结果表明,全省91个饮用水水源地中水质达标的有83个,达标率为91.2%,其中,河流型水源地达标率为93.3%,湖库型水源地达标率为87%,地下水型水源地达标率为87%.     

The identifiability of parameters in a water quality model of the Biebrza River, Poland

The identifiability of model parameters of a steady state water quality model of the Biebrza River and the resulting variation in model results was examined by applying the Monte Carlo method which combines calibration, identifiability analysis, uncertainty analysis, and sensitivity analysis. The water quality model simulates the steady state concentration profiles of chloride, phosphate, ammonium, and nitrate as a function of distance along a river. The water quality model with the best combination of parameter values simulates the observed concentrations very well. However, the range of possible modelled concentrations obtained for other more or less equally eligible combinations of parameter values is rather wide. This range in model outcomes reflects possible errors in the model parameters. Discrepancies between the range in model outcomes and the validation data set are only caused by errors in model structure, or (measurement) errors in boundary conditions or input variables. In this sense the validation procedure is a test of model capability, where the effects of calibration errors are filtered out. It is concluded that, despite some slight deviations between model outcome and observations, the model is successful in simulating the spatial pattern of nutrient concentrations in the Biebrza River.