丹江口水库水体氨氮浓度时空变化特征

丹江口水库作为南水北调中线工程的水源地,其水质状况不仅关系到库区水质安全,而且还直接影响着中线工程调水的成败。通过对丹江口水库氨氮(NH3-N)浓度的动态监测研究,探讨分析了丹江口水库水体氨氮的时空变化规律及其影响因素。结果表明:丹江口水库库区水体氨氮污染主要来自于入库干、支流,入库支流氨氮浓度最大,入库干流断面氨氮浓度次之;季节上总体呈现旱季枯水期氨氮浓度高,雨季丰水期氨氮浓度低的变化特征;空间上,汉江库区表现为氨氮浓度沿程递减,而丹江库区出现下游断面氨氮浓度大于上游断面的情况,存在底泥释放污染。根据分析结果,提出了具有针对性的丹江口水库污染防控措施。     

南水北调中线工程水源地的水质保护

介绍了南水北调中线工程水源地丹江口水库的水质现状,分析了影响因素及存在的问题。指出了目前丹江口水库总体水质良好,符合水源地水质要求,但库周和上游地区水污染防治严重滞后,是水库水质的潜在隐患,应加大治理力度,采取有效措施,以保护丹江口水库水质,确保一库清水向北流。丹江口水库库区污染主要是农业非点源污染及库汊区水体的污染,针对污染现状,提出了对策建议。     

丹江口水库水体中微量有机污染物种类初探

丹江水库是南水北调中线工程的水源地，其水质优劣对工程效益有直接影响，长江流域水环境监测中心首次采用色－质联用仪，分别于１９９５年枯水期和丰水期，对丹江口水库水体中的微量有机污染物，进行了初步探查，基本掌握了丹江口水库微量有机物污染分布状况及库区主要污染物种，为库区及水源地的水控制与水资源保护及规划提供了极为重要的科学依据。     

丹江口水库水质现状及水资源可持续发展策略探讨

丹江口水库作为南水北调中线工程的水源地,水质状况对实现向京津冀地区安全供水至关重要。基于库区水质的总体评价,从点源污染和非点源污染及内源污染3个方面,分别论述了水质污染的来源及成因,并针对库区水资源利用现状提出了水资源可持续发展的建议。     

丹江口水库中微量有机氯污染物的初步评价

丹江口水库是南水北调中线工程的水源地，其水质优劣对工程效益有直接影响。长江流域水环境监测中心首次采用气相色谱仪-ECD,分别于1995年3月和10月，对丹江口水库水体中的微量有机氯污染物进行了概要性调查。结果表明，丹江口水库中微量有机氯污染物的含量很低，对水体尚未造成污染。     

南水北调中线工程水源区水质现状分析

为了掌握南水北调中线工程水源区水资源的水质情况,依据2012~2014年水源区水质实测资料,参照《地表水环境质量标准》(GB3838-2002),采用单因子评价法,选用21项指标对丹江口水库直接入库河流、水功能区、省界断面、库区的水质进行评价,并分析了入河排污口的污染情况。评价结果表明,南水北调中线工程水源区河流水质情况总体为良,部分污染严重的河流污染整治已初见成效,部分支流短期内水质难以达到要求;主要存在的问题有产业结构不合理、污水处理设施未充分运行。根据水源区水质评价结果和存在的问题,提出了相关建议及水源区的水资源保护措施。     

丹江口水库水质的遥感监测

丹江口水库作为南水北调中线工程的水源地,其水质安全将直接影响到调水工程的成败。根据丹江口库区2012年3月25日和8月9日的两幅HJ卫星遥感影像,结合同步的实测水质参数,采用经验反演模型对丹江口水库叶绿素a(Chl_a)浓度、总磷(TP)浓度和水体透明度(SD)进行了定量反演研究。结果显示,无论是枯水期和丰水期,丹库和汉库入库口的Chl_a浓度和TP浓度都要高于其他区域,而入库口区域的SD要低于其他区域。通过分析14项实测水质指标的主成分分析结果和丹江口库区LULC遥感解译结果发现,枯水期库区TP主要来源于库区上游城镇生活污水和工业废水,而丰水期TP主要来自于农业面源污染。SD反演结果还显示,由于汉江上游降雨量大,水土流失严重,使得汉库水体透明度明显低于丹库。利用Chl_a反演结果对丹江口水库的水体营养状态进行分析后发现,在丹库、汉库入库口区域以及水体流通性较小的狭小水体,水库水体达到了轻度富营养化状态,因此,应该加强对库区面源污染的控制和生态环境修复。     

南水北调中线丹江口库区及汇水支流水质现状与污染防治对策

丹江口水库作为南水北调中线工程的水源地,其水体污染状况将直接影响到调水水质,本文在对丹江库区及六条主要汇水支流地水质情况全面调查的基础上,分析了其污染状况、主要污染源及主要的环境问题,并根据调水水质要求提出了总量控制目标和防治对策。     

丹江口库区水资源保护管理的思考

丹江口水库作为南水北调中线工程水源地,其水质安全是工程成败的关键。在分析评价丹江口库区水资源质量状况的基础上,系统梳理近年来库区水资源保护工作的进展情况,认真分析当前库区水资源保护管理工作中存在的主要问题,有针对性地提出了下阶段进一步加强库区水资源保护工作的建议,确保"一江清水永续北送"。     

南水北调中线水源地丹江口水库水质安全保障对策研究

水质安全是决定南水北调中线工程成败的最关键因素,水质安全保障是水库日常管理工作的首要任务。目前,丹江口水库水源区存在污染源类型复杂、面源污染突出、部分支流污染严重、库湾存在富营养化趋势、消落区经济发展与水质保护矛盾突出等问题,这些都是丹江口水库水质安全保障工作面临的挑战。对丹江口水库水质安全问题的主要成因进行了分析,建议从政策制度、管理机制以及工程技术措施等方面建立水质安全保障体系。     

Call for Papers

正As the eldest and most distributed professional journal of water industry,Water Wastewater Engineering(W WE)gained very wide acceptance from the colleagues working in this field in this country since start publication in 1964.Now it is administrated by the Ministry of Construction of the People’s Republic of China and sponsored by the China Civil Engineering Society etc.     

地下厂房施工过程的三维非线性数值模拟分析

根据冗各电站地下厂房开挖支护的施工顺序,以隐式杆单元模拟锚杆,以壳单元模拟混凝土喷层,采用三维非线性有限元技术,对洞室群的开挖支护动态过程进行了模拟计算。通过三维非线性有限元计算分析得到:洞室群动态开挖过程中围岩应力变形的分布规律,围岩塑性区的发展规律,锚杆受力变化情况。计算结果表明:整个开挖过程中,洞周围岩位移变化规律正常,量值较小,塑性区主要分布在洞室周边,围岩稳定性较好;但在洞室交叉口处围岩的变形较大,出现较大范围的塑性区,在此基础上提出了支护措施优化方案,并对优化方案的效果进行了评价。     

Evaluation of freshwater mussel relocation as a conservation and management strategy

The relocation of unionacean mussels is commonly used as a conservation and management tool in large rivers and streams. Relocation has been used to recolonize areas where mussel populations have been eliminated by prior pollution events, to remove mussels from construction zones and to re-establish populations of endangered species. More recently, relocation has been used to protect native freshwater mussels from colonization by the exotic zebra mussel Dreissena polymorpha. We conducted a literature review of mussel relocations and evaluated their relative success as a conservation and management strategy. We found that 43% of all relocations were conducted because of construction projects that were forced to comply with the Endangered Species Act 1973 and that only 16% were monitored for five or more consecutive years. Most (43%) relocation projects were conducted from July to September, presumably a period when reproductive stress is relatively low for most species and the metabolic rate is sufficient for reburrowing in the substrate. The mortality of relocated mussels was unreported in 27% of projects; reported mortality varied widely among projects and species and was difficult to assess. The mean mortality of relocated mussels was 49% based on an average recovery rate of 43%. There is little guidance on the methods for relocation or for monitoring the subsequent long-term status of relocated mussels. Based on this evaluation, research is needed to develop criteria for selecting a suitable relocation site and to establish appropriate methods and guidelines for conducting relocation projects.     

基于模型试验的河床砂砾石层基本特性研究

为了经济可靠地确定深厚覆盖层的基本特性参数,以大渡河双江口水电站坝基河床砂砾石层基本特性研究为工程背景,进行大尺寸模型试验,研究河床砂砾石层的旁压模量和动探击数随密度、级配以及上覆压力的变化规律。根据室内模型试验结果,结合现场旁压试验及钻孔试验成果,推断出坝址区河床砂砾石相关层位的密度,并依此进行砂砾石室内力学试验,获得设计所需力学参数。研究成果可为深厚覆盖层基本特性测试提供新的方法。     

库水波动下库岸边坡地下水浸润线解析解及误差分析

解析法是库岸边坡地下水浸润线计算中便于实际应用的方法,但该方法须基于若干假定并对潜水运动基本方程线性化后才能求解。针对各假定和线性化过程建立不同的地下水渗流数学模型,用解析法和有限元法解答上述数学模型,分析各误差大小及其规律。结果表明：库岸垂直处理带来的误差要小于方程线性化处理和不考虑非饱和渗流带来的误差,而且它们都随渗透系数变大而减小;在三峡库区库水调度情况下,假定库水位等速变化带来的误差对大多岸坡而言可以忽略;计算库岸边坡地下水浸润线时,解析法只适用于水位变化幅度相比含水层厚度较小,且几何边界规则、岩土结构简单、岩土体渗透性较好时的情况。     

SPATIAL AND TEMPORAL WATER QUALITY VARIABILITY IN AQUATIC HABITATS OF A CULTIVATED FLOODPLAIN

The floodplains of lowland rivers contain diverse aquatic habitats that provide valuable ecosystem services but are perturbed when intensively cultivated. Hydrologic, water chemistry and biological (fish) conditions in five aquatic habitats along the Coldwater River, Mississippi, were measured for more than 4 years: the river, two severed meanders that functioned as backwaters, a managed wetland and an ephemeral channel draining cultivated fields. Off‐channel habitats were connected to downstream regions 0.10% to 32% of the dry season and 24% to 67% of the wet season. The median temperatures for the five monitored sites ranged from 18°C to 23°C, the median total solids concentration for all sites was 135 mg L^?1, the median total phosphorus was 0.29 mg L^?1 and the median total nitrogen was 1.56 mg L^?1. Chemical and physical water quality displayed strong seasonal differences between the wet winter/spring and the dry summer/fall periods so that temporal variation consisted of gradual seasonal trends superimposed on strong diurnal variations. All off‐channel habitats exhibited periods of hypoxia and temperatures >30°C during the dry season. Between‐site gradients of water and habitat quality were strongly coupled to water depth and runoff loading. The rehabilitation of one backwater by increasing water depth and diverting agricultural runoff was associated with improved water quality and fish species richness relative to an adjacent untreated backwater. The diversion of polluted runoff and the use of water control structures to maintain greater water depth were observed to be effective management tools, but the former reduces the water supply to habitats that tend to dry up and the latter reduces connectivity. Published in 2011 by John Wiley & Sons, Ltd.     

Changes in Summer Irrigated Crop Area and Water Use in Southeastern Turkey from 1993 to 2002: Implications for Current and Future Water Resources

Changes in summer irrigated cropland acreage and related water use are estimated from satellite remote sensing and ancillary data in semi-arid Southeastern Turkey where traditionally dry agricultural lands are being rapidly transformed into irrigated fields with the help of water from the Euphrates-Tigris Rivers. An image classification methodology based on thresholding of Landsat NDVI images from the peak summer period reveals that the total area of summer irrigated crops has increased three-fold (from 35,000 ha to over 100,000) in the Harran Plain between 1993 and 2002. Coupled analysis of annual irrigated crop area from remote sensing and potential evapotranspiration based estimates of irrigation water requirements for cotton indicate a corresponding increase in agricultural water use from about 370 million cubic meters to over one billion cubic meters, a volume in accordance with the state estimates. These estimates have important implications for understanding the rapid changes in current agricultural withdrawals in Southeastern Turkey and form a quantitative basis for exploring the changes in future water demands in the region. For example, expansion of irrigated lands have led to a steady decrease in potential evaporation due to increased roughness and decreased humidity deficit in the Harran Plain. Assuming that the changes in future evaporation conditions will be of similar nature, water use for irrigation is expected to decrease over 40 percent in future irrigation sites. Incorporating this decrease in overall planning of the irrigation projects currently under construction should lead to improved management, and by extension, sustainability of water resources in the region.     

基于BP神经网络-马尔科夫链模型的隧道围岩位移预测

在隧道工程施工中,围岩位移预测起着很重要的作用。将BP神经网络-马尔科夫链模型引入到隧道围岩位移预测中来,通过对训练样本的学习,利用BP神经网络实现了对位移时间序列的滚动预测,同时得到了实测值与预测值的相对误差;在此基础上利用马尔科夫链对相对误差进行修正,有效地提高了预测结果的精度。并将该模型应用于某公路隧道拱顶下沉位移时序预测中,结果表明该模型具有精度高、科学可靠的特点,为隧道围岩变形的预测提供了新的途径。     

Short communication. Pipelines as a refuge for freshwater snails

In the lower River Murray, Australia, populations of gastropods have declined markedly over the past 40 years. Of the native fauna of about 18 species, only the ancylid Ferrissia petterdi remains common (but in patches), and another five species feature in sporadic local resurgences. Until recently the viviparid Notopala was thought to be extinct. The introduced physid Physa acuta is widespread, but in low numbers. The decline probably is associated with flow regulation, high turbidity and the introduction of common carp. Snail populations have persisted, however, in irrigation pipelines fed from the river, where they periodically cause blockages. This paper reports the discovery of the only known populaion of Notopala hanleyi in a pipeline where the inner wall accumulates microbial and other organic matter, providing high quality food for snails. In the Murray before regulation most of the periphytic biomass was probably microbial, as fluctuating water levels would have maintained littoral communities in a highly productive, early state of succession his postulated that, by stabilizing seasonal water levels, regulation has promoted the production of filamentous green algae, an inferior food source, and so displaced snail populations from the open aquatic environment.     

Spatio‐temporal variation of gross CO2 and CH4 diffusive emissions from Australian reservoirs and natural aquatic ecosystems,and estimation of net reservoir emissions

Carbon dioxide (CO₂) and methane (CH₄) diffusive emissions were measured during two field surveys in Queensland and Tasmania, Australia, using the floating chamber method. Bubbling and degassing emissions in 2010 were estimated in Koombooloomba Dam reservoir using only inverted funnels and gas concentrations, respectively. A total of 14 reservoirs and 16 rivers and lakes were sampled from 2006 to 2010. Spatial variation was substantial within each water body, as well as between them. The main drivers of diffusive emission variation were physiographic region and climate, with a clear demarcation being observed between diffusive emissions from tropical Queensland and temperate Tasmania, and between the humid West Coast Range (Tasmania) and dry Central Plateau (Tasmania). Higher CO₂ and CH₄ diffusive emissions were observed during the dry season, when long water residence times would promote organic matter degradation. Estimated total gross emissions, including diffusive, bubbling and degassing emissions, for Koombooloomba Dam reservoir were about 1.5 × 10⁶ t CO₂eq km² per year, or 24 × 10⁶ t CO₂eq per year. This corresponds to a plant emission factor of 3.18 kg CO₂eq MWh^?1. Using an estimate of terrestrial emissions derived from literature data for the Tully River catchment area, rough estimated net emissions from the catchment area are about 44 kt CO₂eq per year, or 5.83 kg CO₂eq MWh^?1, which is in the lower range of the studied reservoirs.