浅谈小型水库除险加固问题的几点分析

本文针对小型水库除险加固设计中常存在的问题进行分析,研究小型水库除险加固中有关技术问题,对小型水库除险加固中的几个技术问题作了简要总结。     

基于小型水库除险加固的施工质量控制问题及对策分析

在小型水库除险加固施工过程中,合理控制施工质量有着至关重要的作用。施工质量得不到保障会影响施工进度,增加工程费用,同时还留下了隐患。小型水库的除险加固工作是现阶段基层水利单位共同关注的首要问题。本文针对小型水库建设中的特点,详细阐述了其中存在的问题,并根据这一系列的问题提出改进措施。     

试论小型土石坝水库的病险分析及除险加固措施

由于历史的原因,在进行建设的时候我国的小型水库所遵从的标准很低,加上管理并不完善,经过了很多年的运行之后,普遍存在着防洪抢险能力不充足、大坝渗水情况严重、大坝本身结构不安全、大坝抗地震能力不高、大坝内部外部的金属结构出现各种问题等问题.本文结合了实际经验,对于在这种情况下大坝可能出现的问题进行了总结,然后有针对性的对土石方大坝的各种排除危险加固的手段进行了自己的观点表述,希望能够抛砖引玉,和同行共同学习共同提高.     

设计施工因素对城市供水管网水损、水质污染影响的分析

结合笔者多年的工件经验，对城市供水管网规划设计与施工过程中可能导致将来管网水损与水质污染的因素进行了分析、归纳与总结，并提出了相应的建议。     

考虑不同土压力模式的水泥土重力式围护墙抗倾覆稳定性分析

墙前开挖区土压力和墙后土压力模式的确定是水泥土重力式挡土墙抗倾覆稳定性验算的关键,不同土压力模式下抗倾覆系数曲线形态有一定的差异。根据墙体竖向力的平衡确定抗倾覆验算点位置,根据墙体的变形特征,同时考虑由于基坑开挖引起的上覆有效土压力变化引入修正系数α修正墙前后土压力,推导了修正土压力模式下墙体的抗倾覆稳定计算公式,对比分析三种不同土压力模式下Kq曲线的形态特征及其影响因素,结果表明墙前后土压力修正模式更能反映实际状态下墙的倾覆失稳形态,其抗倾覆稳定系数也更加合理。     

小城市排水规划问题探析--汉寿县城排水专业规划为例

本文以汉寿县城排水专业规划为例，分析了小城市排水系统的现状及存在的主要问题，提出小城市排水规划的总体原则及具体对策，并针对小城市污水处埋问题进行了深入探讨。     

The valuation of water quality: Effects of mixing different drinking water qualities

As water supplies increasingly turn to use desalination technologies it becomes relevant to consider the options for remineralization and blending with mineral rich water resources. We present a method for analyzing economic consequences due to changes in drinking water mineral content. Included impacts are cardiovascular diseases, dental caries, atopic eczema, lifetime of dish and clothes washing machines, heat exchangers, distribution systems, bottled water consumption and soap usage. The method includes an uncertainty assessment that ranks the impacts having the highest influence on the result and associated uncertainty. Effects are calculated for a scenario where 50% of Copenhagen's water supply is substituted by desalinated water. Without remineralization the total impact is expected to be negative (€−0.44 ± 0.2/m³) and individual impacts expected in the range of €0.01-0.51/m³ delivered water. Health impacts have the highest contribution to impact size and uncertainty. With remineralization it is possible to reduce several negative impacts and the total impact is expected to be positive (€0.14 ± 0.08/m³).     

Predicting the vulnerability of reservoirs to poor water quality and cyanobacterial blooms

Cyanobacterial blooms in drinking water reservoirs present a major ecosystem functioning and human health issue. The ability to predict reservoir vulnerability to these blooms would provide information critical for decision making, hazard prevention and management. We developed a new, comparative index of vulnerability based on simple measures of reservoir and catchment characteristics, rather than water quality data, which were instead used to test the index’s effectiveness. Testing was based on water quality data collected over a number of seasons and years from 15 drinking water reservoirs in subtropical, southeast Queensland. The index correlated significantly and strongly with algal cell densities, including potentially toxic cyanobacteria, as well as with the proportions of cyanobacteria in summer months. The index also performed better than each of the measures of reservoir and catchment characteristics alone, and as such, was able to encapsulate the physical characteristics of subtropical reservoirs, and their catchments, into an effective indicator of the vulnerability to summer blooms. This was further demonstrated by calculating the index for a new reservoir to be built within the study region. Under planned dimensions and land use, a comparatively high level of vulnerability was reached within a few years. However, the index score and the number of years taken to reach a similar level of vulnerability could be reduced simply by decreasing the percentage of grazing land cover via revegetation within the catchment. With climate change, continued river impoundment and the growing demand for potable water, our index has potential decision making benefits when planning future reservoirs to reduce their vulnerability to cyanobacterial blooms.     

两种混养模式海水池塘浮游生物的群落结构及其粒径特征

为了解"海蜇-缢蛏-牙鲆-对虾"和"刺参-对虾"两种混养模式海水池塘生态系统特征,于2013年4月—2014年3月采用野外调查方法研究了辽宁省两种混养模式的池塘浮游生物群落结构及其粒径特征。结果表明:"海蜇-缢蛏-牙鲆-对虾"混养池塘共检出浮游植物48种,以硅藻门和绿藻门种类为主,浮游植物平均密度和生物量分别为26.50×10~5 ind./L、0.90 mg/L,共检出浮游动物24种,主要为原生动物和桡足类,浮游动物平均密度和生物量分别为81.57 ind./L、0.51 mg/L,浮游植物、浮游动物的多样性指数平均值分别为2.28、1.49;"刺参-对虾"混养池塘共检出浮游植物57种,也以硅藻门和绿藻门种类为主,浮游植物平均密度和生物量分别为3.99×10~5 ind./L、0.41 mg/L,共检出浮游动物33种,主要为原生动物和桡足类,浮游动物平均密度和生物量分别为73.19 ind./L、0.13 mg/L,浮游植物、浮游动物的多样性指数平均值分别为2.20、0.93;两种混养池塘浮游植物粒径为2.50~69.62μm,浮游动物粒径为11.09~560.41μm。研究表明,"海蜇-缢蛏-牙鲆-对虾"混养池塘的浮游生物种类相对较少,但其密度和生物量较大。     

煤岩体在水中高压放电下致裂效果的定量评价

为了研究水中高压放电对低渗透性煤体的致裂效果,设计在3MPa水压中高压脉冲放电压裂试验,利用CT扫描系统和孔裂隙特征分析软件,通过研究煤样内部裂隙的几何形态参数、分形维数及裂隙宽度概率密度函数的变化,定量分析煤岩体在不同加载压裂方式下的裂纹扩展规律。研究结果表明:在相同水压条件下,高压电脉冲水压压裂煤体的效果明显优于单纯3 MPa水压的压裂效果;放电电压越高,煤样内部裂隙的数量和节点数量越多、总长度越长、平均宽度越宽以及裂隙率越大;放电电压越高,分形维数和裂隙分布初值的对数值越大,即裂隙越复杂,大裂隙所占比例越大;放电电压越高,裂隙宽度越宽,宽度分布范围也越广。由此可见,水中高压脉冲放电对煤体具有良好的致裂效果。     

Development of predictive models for geosmin-related taste and odor in Kansas, USA, drinking water reservoirs

The presence of taste and odor compounds can greatly reduce the quality of drinking water supplies. Because the monetary costs associated with the removal of these compounds can be high, it is impractical for most facilities to continuously treat their raw water. Instead, new tools are needed to help predict when taste and odor events may be most likely to occur. Water quality data were collected between June and October in 2006-2007 from five Kansas (USA) reservoirs in order to develop predictive models for geosmin, a major taste and odor compound; two of these reservoirs were also sampled during specific taste and odor events in December 2006 and January 2007. Lake trophic state alone was not a good predictor of geosmin concentrations as the highest average geosmin concentration was observed in the reservoir with the lowest nutrient and chlorophyll a concentrations. In addition, taste and odor events were not confined to summer months; elevated geosmin concentrations were observed in several reservoirs during the winter. Growth limitation by inorganic phosphorus appeared to be the primary determinant of geosmin production by algal cells in these reservoirs.     

山西引黄沿线水库水质富营养化评价与分析

介绍了山西引黄沿线万家寨水库和汾河水库的工程概况,采用营养分级评分法与综合营养状态指数法,对两座水库的水质富营养化进行了评价分析,指出两座水库均存在由中营养向富营养转化的风险,应采取必要的措施防止水库水质富营养化的发生。     

Continuous-flow laboratory simulation of stream water quality changes downstream of an untreated wastewater discharge

In regions of the world with poor provision of wastewater treatment, raw sewage is often discharged directly into surface waters. This paper describes an experimental evaluation of the fate of two organic chemicals under these conditions using an artificial channel cascade fed with a mix of settled sewage and river water at its upstream end and operated under continuous steady-state conditions. The experiments underpin an environmental risk assessment methodology based on the idea of an “impact zone” (IZ) - the zone downstream of wastewater emission in which water quality is severely impaired by high concentrations of unionised ammonia, nitrite and biochemical oxygen demand (BOD). Radiolabelled dodecane-6-benzene sulphonate (DOBS) and aniline hydrochloride were used as the model chemical and reference compound respectively. Rapid changes in ¹⁴C counts were observed with flow-time for both these materials. These changes were most likely to be due to complete mineralisation. A dissipation half-life of approximately 7.1 h was observed for the ¹⁴C label with DOBS. The end of the IZ was defined as the point at which the concentration of both unionised ammonia and nitrite fell below their respective predicted no-effect concentrations for salmonids. At these points in the cascade, approximately 83 and 90% of the initial concentration of ¹⁴C had been removed from the water column, respectively. A simple model of mineral nitrogen transformations based on Michaelis-Menten kinetics was fitted to observed concentrations of NH₄, NO₂ and NO₃. The cascade is intended to provide a confirmatory methodology for assessing the ecological risks of chemicals under direct discharge conditions.     

Influence of temperature and river discharge on water quality of the western scheldt estuary

Dissolved oxygen concentrations and information on the nitrification process collected respectively during a 14- and a 5-year period in the self-purifying part of the Western Scheldt estuary have been studied. In the polluted part of the stream, ammonium concentrations over the period 1967–1977 have been considered as well.This paper demonstrates the high variability of these 3 parameters (oxygen, start of the nitrification process, ammonium) owing to the hydrological conditions: temperature and river discharge.Neither the levels of ammonium in the polluted upper part of the stream, nor the concentrations of nitrate and dissolved oxygen in the recuperation part of the Scheldt estuary have changed significantly during the periods studied (respectively 5, 10 and 14 years). A relation between these parameters and time could be hidden by hydrological factors.Water quality of a stream can be assessed by interpreting oxygen, nitrate, and ammonium concentrations, only if all environmental and hydrodynamical parameters are known simultaneously.     

分质供水住宅建筑给水设计秒流量计算

对同一分质供水住宅小区的给水设计秒流量用不同的两种方法进行了计算并做了比较，阐明了分质供水住宅建筑给水设计秒流量计算应以不同给水管道对应的卫生器具给水当量为准，才能得出正确、合理的结果。