长江枝城水文站TES-91泥沙在线监测系统比测试验分析

为了论证在线光学测试仪器在长江上荆江河段的适用性,进行了TES-91泥沙在线监测系统的比测试验分析。介绍了长江枝城水文站TES-91泥沙在线监测系统的系统组成、工作原理,并对其设备稳定性、仪器示值与实测断面平均含沙量分别进行比测率定试验。结果表明:仪器性能稳定,在线监测泥沙与实测断面平均含沙量具有良好的相关关系。将TES-91测得的含沙量与实测断面平均含沙量建立模型,计算得到的断面含沙量精度较高,适用于枝城水文站泥沙在线监测和报汛。     

OBS-3A浊度仪在含沙量测验中的应用分析

通过水文缆道对测验垂线及测点准确定位,OBS-3A浊度仪和横式采样器便可在同一位置同步测验。利用采集测点的含沙量与相应浊度值,建立两者的相关关系。分析影响浊度值变化的主要原因,基于OBS实测浊度值,推求含沙量的测验成果是否满足精度要求。研究表明,OBS-3A浓度仪可快速确定天然水体中的含沙量,且精度较高,具有一定的推广应用价值。     

采用浊度监测实现悬移质泥沙监测自动化的探讨

介绍了南宁水文站通过对水体浊度参数测试,得到浊度与含沙量关系,研究新悬移质泥沙监测模式,实现悬移质泥沙监测自动化,推进水文信息化进程适应经济发展,为防灾减灾决策,及时、准确提供科学依据。     

ASM在近底泥沙浓度剖面观测中的应用研究

ASM是现场悬浮物浓度的高分辨率剖面观测仪,在测量悬沙浓度方面具有多点同步的优点。将ASM应用于长江口北槽近底三脚架观测系统,观测近底1m的泥沙浓度剖面。结合同步的OBS实测数据,对比分析了ASM所测浊度数据的可靠性及敏感度。通过对ASM的浊度参数进行含沙量转换的室内标定实验,分析了水体浊度、悬浮物颗粒和浓度间的关系,讨论了泥沙颗粒大小及级配差对ASM观测的影响。结合近底层水沙观测系统,给出了ASM的应用前景,可为基于该仪器的河口海岸滩槽水沙观测及相关研究提供科学依据。     

浊度仪在映秀湾水电站泥沙浓度监测中的应用

利用浊度法的优点和相关标准,结合流域水沙特征,设计了一种可适用于泥沙浓度监测的散射式浊度仪,该浊度仪测量重复性好,准确度高,在泥沙浓度0~3 kg/m3范围内,其浊度测值与泥沙浓度具有良好的线性关系。映秀湾水电站现场应用表明,以该浊度仪为基础建立的泥沙浓度在线监测系统能满足泥沙浓度的监测要求,较好地反映发电水体泥沙浓度的变化趋势。     

非黏性沙级配对浊度法测量含沙量的影响

利用浊度仪测量水流含沙量时,泥沙颗粒级配和矿物成分是影响浊度仪标定结果的主要泥沙因素。采用黄河原型非黏性沙配制不同粒径、不同含沙量浑水水体,开展固定粒径、粗细沙、混合沙等多组次试验研究,对黄河天然沙粒径及级配对浊度仪输出浊度的影响进行定量分析和机制探讨。结果表明:固定含沙量条件下,非黏性泥沙粒径对水体浊度的影响特征符合Mie散射定律;含沙量变化对浊度仪输出浊度的影响数量级为10～10²,泥沙颗粒粒径变化对浊度仪输出浊度的影响数量级为10^-1～1;相同含沙量条件下,悬沙比表面积与浊度仪输出浊度符合线性分布。建立了考虑非黏性沙级配影响的含沙量与浊度关系模型,能够较准确地反映非黏性沙粒径及泥沙浓度对水体浊度的影响,可为浊度与含沙量关系的准确率定及测量结果的校准提供可靠依据。     

自动化走航式全断面积宽法悬移质输沙率测验关键技术的研究

传统悬移质输沙率测验为人工测验方式,耗时耗力、效率低下。由于低效率测验方式的泥沙信息不能满足经济社会发展的需求,只有改革悬移质泥沙测验方式,才能实现悬移质输沙率测验自动化。在南宁水文站开展自动化走航式全断面积宽法悬移质输沙率测验关键技术的研究,根据浊度与悬移质泥沙的相应关系建立模型,将悬移质输沙率测验的含沙量监测,通过由浊度监测转为泥沙监测,达到悬移质输沙率测验自动化的目的。     

台湾集集堰沉沙池泥沙浓度与浊度率定关系研究

水体浊度观测为水环境及水资源领域中之例常观测项目,泥沙浓度则为水资源及水利工程中重要之水文观测数据。浊度数据对于水生态环境、水资源利用评估及公共用水营运,为极重要判别指标 泥沙浓度数据则为集水区保育及河道稳定评估规划所需之重要基本数据。现行浊度观测方式及仪器,相对于传统泥沙浓度之观测,其仪器自动化程度高、价格较低,且设站较为简易方便且普遍。虽河川中悬移泥沙浓度与浊度之物理定义不同,但在工程实务应用上仍有许多泥沙浓度数据以浊度数据来替代表示。本文研究特定水沙条件下之浊度与浓度率定关系,并以集集拦河堰为案例,探讨试样水体浊度、浓度观测数值在不同含沙量条件下之对应及量化关系规律,并依ISO标准规范,进行不确定度分析及误差分析。研究成果显示,浊度观测方式之重现性及精度良好,且浊度与浓度测值间对应率定关系明确,但此率定关系与泥沙类别、泥沙粒径及分布组成条件密切相关。参照本研究所提出之泥沙浊度与浓度观测之率定关系规律,可以利用现已普遍设站之水质观测站之浊度观测数据,建立推估特定流域河道之水、沙特性关系。     

B超在含沙量及其垂线分布测量中的首次应用

针对河港工模型试验中的泥沙测量与研究,借助B超仪和三维定位行走控制平台构建了一个含沙量及其垂线分布的分析与测量系统。系统利用B超成像技术获取含沙水流中悬浮沙粒的图像,针对B超图像编写含沙量分析软件,分析图像中指定区域的沙粒成像光斑面积的灰度浓度。通过率定试验,建立灰度浓度与水中实际含沙量的对应关系,并利用这种对应关系来计算待测含沙量。系统实现了较低含沙量及其垂线分布的在线同步分析与测量,具有操作简单、直观可视、实时性好、灵敏度高的特点。     

深圳潮洪河流水文泥沙在线观测及整编方法

受潮汐影响的河流,水力条件复杂,潮水位和潮流量之间无相关关系,难以用水位推求流量获得流量过程。依据断面流量与断面平均流速具有较好同步性和一致性的特点,建立了ADCP测量断面平均流速和代表线流速之间相关关系和使用代表线流速推求断面流量的方法。通过对不同来水(潮)的含沙量粒径组成的分析试验,摸索出OBS现场自动测沙仪的率定方法,建立了不同来水(潮)来沙条件下的浊度与点含沙量的率定关系。将所研究的方法应用于深圳河的在线潮流量和输沙率过程推算中,取得了较好的效果。     

OBS浊度计在三水、马口及岗根水文站含沙量比测试验研究

根据光学后向散射浊度计测量水体浊度与人工传统含沙量分析在三水、马口及岗根水文站同步比测试验研究分析,揭示了珠江三角洲部分河道水体浊度与含沙量的相互关系,探讨了光学后向散射浊度计应用于珠江三角洲河道含沙量分析的前景。     

Calibration of turbidity meter and acoustic doppler velocimetry (Triton‐ADV) for sediment types present in drained peatland headwaters: Focus on particulate organic peat

Suspended sediments have a clear impact on fluvial water quality and aquatic habitats. As the concentrations are highly variable, continuous measurement offers a good way to provide accurate and precise values of sediment concentration and yield. However, there is a lack of information regarding the effect of organic peat particles, which typically appear in boreal fluvial systems. In the present study, the effect of different types of suspended sediments on calibration of a turbidity meter and an acoustic Doppler velocimetry (Triton‐ADV) was studied in laboratory conditions. The measurements were performed using particulate organic peat, clay and silt with several concentrations ranging from clear water to 3500 mg L^?1. The present study primarily provides organic peat sediment calibration data for used sensors. Regression equations were developed for the different sediment. The results indicate that particle size, shape, concentration and sediment type have an effect on calibration. When the turbidity and the ADV calibration were performed for different particle size groups, sediment types and concentrations, the calibration and suspended solids calculation error was reduced. For the turbidity sensor used, the reliable upper continuous measurement limit for clay, peat and silt sediments was found to be at 1000, 2500 and 3500 mg L^?1, respectively. The ADV‐sensor was noticed to be reliable only with fine particles. The results enable easy and first step calibration and error assessment for automatic turbidity and acoustic monitoring of the suspended sediment quality typically present in headwater fluvial systems. This study can be used to evaluate the effect of different sediments on turbidity and ADV‐measuring error and reliability during changing particles size distributions, characteristics and concentrations. The laboratory‐based approach used in this study indicates that the shape of organic peat particles has an influence on sensor calibration, especially when suspended sediment concentrations are high. Copyright © 2009 John Wiley & Sons, Ltd.     

江水源热泵换热器污垢形成的关键水质因素分析

江水引起的热泵换热器结垢不仅会增大机组进出口阻力,还会导致换热器的换热效率下降。江水水质对换热器污染起决定作用。江水源热泵污垢形成的关键水质因素及相关性分析是热泵用水体评价和水处理决策的基础。通过对重庆地区长江和嘉陵江水质测试分析,并与现行允许水质指标的对比,表明含沙量和浊度是江水源热泵的重点解决问题。对江水源热泵换热器污垢的成份分析则表明,污垢是以小粒径泥沙的颗粒污垢为主。从而确定关键水质因素是含沙量和浊度。根据与实际江水泥沙配置保持一致的自配水样分析,得到了含沙量与浊度的关系方程,误差分析表明预测值与实测值能较好地吻合。     

Numerical and experimental study of continuous and discontinuous turbidity currents on a flat slope

When the sediment and the dissolved matter laden in the river meet a clear water in reservoirs, the turbid water will plunge and spread into the clear water, forming the turbidity current and influencing the water quality and the life of the reservoir. Due to the unsteady nature of the flood, the turbidity current is unsteady. In the present study, we use the MIKE 3 computational fluid dynamics code to simulate continuous and discontinuous turbidity currents on a flat slope. With the model used by us, the turbulence is divided into two parts: the horizontal turbulence and the vertical turbulence, which are separately modeled by the Smagorinsky model and our model to capture the anisotropic turbulence. In this model, the sediment settling and deposition are considered. The simulation results concerning the flume water surface level, the front velocity and sediment concentration profiles are found consistent with the experimental data, particularly, for the sediment concentration profiles with an absolute mean error of 0.026 kg/m~3 and the root mean square error of 0.046 kg/m~3. This finding suggests that this model can be used to well predict the turbidity current on the flat slope.     

紫外可见光谱水质测量仪器的应用

基于紫外-可见吸收光谱分析技术的水质测量仪器,具备在线、连续、实时的测量能力,在现场或野外进行水质在线监测时,直接沉入待测水体的不同深度,快速识别硝酸盐、亚硝酸盐和大部分有机污染物,获得连续、实时的水质数据,并能对多种水质参数进行同时测量分析,具有速度快、无污染、重复性好、精度高、维护量少等优点。在河流、湖泊、饮用水水源地等处的水质预警预报系统中加以应用,可以成为水质污染事故早期预警预报的有效工具。     

Calibration of CE-QUAL-W2 for a monomictic reservoir in a monsoon climate area.

The impact of inflow mixing on reservoir stratification is significant for reservoirs situated in a monsoon climate area. It cause difficulty in the calibration of a two-dimensional hydrodynamic and water quality model, CE-QUAL-W2 that was recently adopted for a real-time turbidity monitoring and modelling system (RTMMS) for a reservoir in Korea. This paper presents a systematic calibration and verification processe of the model for the reservoir. A sensitivity analysis showed that wind sheltering, Chezy, and sediment heat exchange coefficients are most sensitive to stratification structure. Inflow temperature was very sensitive during a year of normal precipitation, but it is not significant during a year of drought. Residual analysis revealed that the model has shortcomings in the simulation of water temperature near the metalimnetic zone without calibration. After calibration, however, the absolute mean errors between observed and simulated values were placed within 0.116-1.190 degrees C. Its performance was maintained under heavy flood events during the verification stage, which implies that the model is ready to use for the simulation of turbidity plume in the RTMMS under various hydrologic conditions. The suggested model calibration strategy and relevant results may be adopted for other reservoirs located in a monsoon climate area.     

长江口枯水期最大浑浊带形成机制

用ADCP获得了长江口最大浑浊带内的高频率和高分辨率流速和悬沙浓度数据,对不同定点站位和走航断面的悬沙浓度、流速和盐度数据进行了分析,同时对不同站位的再悬浮通量以及悬沙输运机制也进行了计算,进而讨论了长江口枯水期最大浑浊带的形成机制。结果表明,枯水期的长江口处于淤积状态,再悬浮通量较小,其数量级介于10-4-10-7kg·m-2s-1之间;平均流输运在整个悬沙输送中占主导地位,斯托克斯漂移效应、垂向环流和潮振荡的垂向切变作用对悬沙输运也有着重要作用;通过分析走航断面的数据确定了枯水期中潮期内最大浑浊带的显著分布区域,“潮泵”作用和河口重力环流作用均在该地区最大浑浊带形成中都发挥着重要作用。