Capacitive sensing technique for silt suspended sediment concentration monitoring

Automated, real-time, and continuous techniques for monitoring suspended sediment concentration in rivers and reservoirs can play an important role in the improvement of the quantity and quality of sediment data, and are valuable to the management of water environment, water conservancy, hazard prevention, and water resources. Research in the monitoring techniques has examined the possibility of using the characteristics of dielectric constants for detecting soil moisture and concentration of air-water two-phase flow, based on the fact that dielectric constants of sediment, air and water are different. A capacitance sensor was developed to monitor the silt suspended sediment concentration (SSSC) in a recent study, following the principle that as SSSC increases in the sediment-water mixture, the apparent dielectric constant of the water sample also increases and therefore the capacitance detected by the sensing system also increases. It is demonstrated that the variations in the concentration of silt sediment correlates positively with the variations in observed capacitance in a linear fashion, and correlates negatively with voltage outputs but also in a linear fashion. The correlation coefficients reached above 0.98. The overall errors in estimated concentrations range between 0.26% and 2.91%. Elements in the capacitance sensor system such as the frequencies of the signal generating system, areas of the electrode plates, and effects of sample temperature have also been evaluated. The results illustrated that the capacitance sensor techniques can be applied to monitoring SSSC automatically and continuously. Also, the range of SSSC in the experiment reached 200 kg/m³; therefore, the application of this technique in practical SSSC monitoring is worthy of further research.     

法国罗瓦尔河口悬移质中的石膏颗粒及表面新生方解石霰石晶体描述

本文介绍在暖温带河口悬移质中发现的石膏颗粒及其表面的新生方解石和霰石晶体。石膏颗粒经受了不同程度的化学和生物化学风化。在一部分风化石膏表面,存在大量的数微米到数十微米大小的方解石和霰石晶体,某些晶体还呈现出亲岩生物遗留的生长纹。由于河口水的溶蚀作用,一部分石膏颗粒已充分碳酸钙化。     

台兰河泥沙变化特征分析

以新疆台兰河为研究对象,对该河流泥沙变化特征进行研究。研究得出:台兰河泥沙主要来源是流域表面的土壤和水流冲刷河床、河岸崩塌挟带的泥沙。河流中泥沙含量多少受流域水土流失程度、洪水类型、植被覆盖率、土壤特性、气候干旱程度、河流水量和洪水集中程度等综合因素影响。河流含沙量年内和年际变化较大,含沙量的沿程分布与径流量的沿程分布大体一致,呈自上而下逐渐增大的趋势。研究结果为流域水资源合理开发利用和防洪减灾提供依据。     

五号桩海区悬移质输运量的计算

It’s very important to study the transportation of suspended matter for the coats engineering. We have to understand the quantity and direction of the movement of suspended matter for studying the change of coast and deposit of sediment on the sea bed. For this porpose we have measured the currents and the quantity of suspended matter near the section B in different seasons since 1983.According to data and calculation, we’ve got the following conclusions: 1) The quantity of suspended matter transported by tidal current through the section B is about 19.6 million tons each year, but the transportation, quantity is the same in both direction of flood tide and ebb tide. 2) The quantity of suspended matter removed by residual current is about 8.57 million tons each year, the direction of tran.spotation points to north‘west. 3) The transportation quantity of suspended matter due to the winddriven current in. storm weather is about 0.95 million, tons each year,the direction of transportation points to south.     

天津港航道悬移质输运特征的观测研究

运用现场观测的天津港航道处水深、流速以及悬沙浓度资料,采用垂向平均的计算方法,得到天津港航道的悬移质 输沙率,讨论当前条件下天津港航道悬移质输沙的特点,为天津港港区及航道附近水域的泥沙输运及淤积研究提供可靠依据。     

Suspended sediment load in the turbidity maximum zone at the Yangtze River Estuary:The trends and causes简

Based on the analysis of suspended sediment elements at estuaries, influence of human activities and estuarine regulation projects on the turbidity maximum zone was studied according to the measurement data between 1959 and 2011. It was found that human activi- ties had little effect on the seaward water while the sharp decrease of sediment volume and concentration in runoff led to the sharp decrease of turbidity maximum zone in the estuary. The concentration at outside sea and Hangzhou Bay did not change, and that along the Subei coast also decreased a little, which had no influence on the turbidity maximum zone. Com- pared with the concentration between 1959 and 1999, the peak of concentration moved up- stream in the estuary, and the concentration in 2000-2009 decreased by about 24.73% with a narrower variation range along the river to the sea. The suspended sediment concentration in North Passage was low in upstream and downstream because of the decrease of seaward sediment and coarsening of bed material, while it was relatively high in the middle due to the influence of sediment cross the north jetty.     

水文过程对河流悬移质化学组成的影响——以珠江流域为例

用等离子体原子发射光谱法（ICP-AES）分析了珠江马口站和三水站1997-1998年度3个典型水文时段径流悬移质中部分金属元素的含量，同时用元素分析仪测定了其中的有机碳、氮的含量，结果表明，在不同性质的水文动力条件下，流域侵蚀产出的河流悬移质的化学组成发生了变化，这主要缘于有机质在悬移质中所占质量分数的差别。汛期增强的水文动力主要表现为对流域土壤矿物的优先侵蚀，虽然有机质的总侵蚀量也同时增加，但在悬移质中的质量分数却相对减少，而在枯水期较弱的水文动力条件下，河流悬移质中有机质的质量分数增加，悬移质中的有机质对液相中的部分重金属元素产生较矿物更大的吸附作用。     

玛纳斯河泥沙特征概述

本文通过玛纳斯河的泥沙资料，分析了玛纳斯河泥沙的一般特性，并对玛纳斯河红山嘴水文站县移质泥沙和推移质泥沙与其它水文要素之间的关系作了论证。     

鲁北平原区河道悬移质泥沙规律浅析

分析了鲁北平原主要排洪河道悬移质泥沙的来源、组成、年内、年际变化及沿程变化规律，水沙关系，输沙量与年径流量、年降水量之间的关系。指出鲁北平原河道泥沙主要有两大来源：一是流域产沙；二是引黄客沙，其中引黄客沙是鲁北平原河道泥沙的主要来源，引黄客沙的大量进入，不但改变了河流泥沙形势，而且加剧了河道淤积，使各河行洪能力较70年代降低了40％～70％。鲁北平原区河流泥沙的输沙量年际变化较大，与年径流量的丰枯变化有较明显的相应性；输沙量年内分配极不均匀，主要集中在汛期（6～9月）。