Quantifying and characterizing contemporary riparian sedimentation

Fluvial processes of erosion, sediment transport and deposition determine the changing form and sedimentary structure of naturally adjusting riparian zones. Riparian sediment storage has both scientific and management importance in relation to: (i) the quantities of sediment that are involved; (ii) the quality of the sediment; and (iii) the dispersal of biological materials, notably the vegetation propagules that are transported and deposited in association with the sediment. After discussing the significance of riparian sedimentation processes, this paper reviews methods for quantifying contemporary sediment deposition within water bodies and their margins. Methods for investigating contemporary riparian sedimentation are given particular emphasis, and the extent to which different methods provide comparable estimates and have been used to support the analysis of different physical and chemical properties of the sediment are outlined. The importance of the following are stressed: (i) selecting a sampling method that is suited to the sedimentation environment; (ii) incorporating careful cross‐calibration if measurements from different methods are to be combined; and (iii) replicating measurements to give more robust estimates if small traps are employed. It is concluded that artificial turf mats provide a useful design of sediment trap across a range of environmental conditions because: (i) their surface roughness reduces problems of sediment removal by flood waters or rainfall; (ii) their pliability permits installation on irregular surfaces; (iii) they can be securely attached to the ground with metal pins to resist high shear stresses from river flows; (iv) they are robust and light and so easily manipulated in the field and laboratory; (v) it is possible to fully recover the deposited sediment to accurately determine the amount of sediment deposited and to support a range of other analyses. Results are presented to illustrate how artificial turf mats can be used to estimate the quantity and quality of deposited sediment and to explore the associated deposition of viable seeds. This provides one example of the important hydroecological role of riparian sedimentation processes and of the potential for the development of innovative, interdisciplinary research on riparian sediment dynamics. Copyright © 2003 John Wiley & Sons, Ltd.     

利用黄河泥沙加固下游大堤

黄河是一条举世闻名的多泥沙河流，善淤、善决、善徒给沿河人民带来对过深重灾难，防洪问题一直是国家的心腹之患。泥沙问题是黄河防洪问题的症结所在。在总结固大堤经验的基础，进行挖河疏浚，淤筑“相对地下河”，已作为黄河治理的一项重大决策付诸实施。     

永定新河治理工程几个关键问题的研究

永定新河是天津市防洪的北部防线。由于受海相来沙淤积 ,河道行洪能力大幅度下降。针对永定新河治理工程设计中涉及到的河道淤积治理方案、闸位比选、防潮闸结构型式及施工方法、闸下减淤清淤措施等诸多问题进行了分析和研究 ,提出了相应的措施和建议     

坨五站中间乳化层快速增长原因及治理方案

胜利采油厂坨五站高含水(95％)原油化学预脱水中，二级沉降罐内油水相之间的中间乳化层增长迅速，引起了一系列问题。现场调查和大量室内测试结果表明，产生这一现象的原因有：油溶性破乳剂WD-1加入点不合理。有2／3的含水原油在通过油水分离器之后才与破乳剂混合；二级沉降罐进油口伸入油相内，油流的冲击达不到中间层；WD-1对坨五站混合原油中的稠油破乳脱水性能欠佳，不能适应坨五站混合原油组成和含水的变化。针对上述各种原因筛选出了性能更好的一种破乳剂1916。根据确定的几种原因采取了相应的措施：将破乳剂加入点改在3个并联油水分离器之前；将二级沉降罐的进油口移到水相内；改用筛选出的破乳剂1916，结果使中间乳化层的增长受到了抑制。图2表4参2。     

微型灌注桩托换技术在地基基础加固工程中的应用

因场地淤泥等软土层深厚,在填方荷载作用下,软弱土层产生固结沉降,引起局部构筑物的不均匀沉降,发生结构破坏。采用微型灌注桩加固满足现场各个限制条件的要求,达到了加固目的。     

柘溪水库泥沙淤积情况调查简介

通过对 1995年柘溪水库泥沙冲淤调查资料的分析 ,对比 196 3年建库时及 1974年库区泥沙冲淤情况 ,获得建库以来库区泥沙沉积率及其泥沙分布的关系曲线 ,可为已建或拟建的同类泥沙淤积分析提供参考。     

聚合硫酸铁处理制革废水

本文研究了几种常用的国产混凝剂处理制革废水的效果，得出聚合硫酸铁是一种比较经济有效的混凝剂，配合ＰＡＭ助凝剂可以取得更好的效果。工艺上采用混凝气浮，可全部去除硫化物，出水总铬≤１ｍｇ／Ｌ，ＣＯＤ去除率可达７０％－８０％。     

The influence of food emulsifiers on fat and sugar dispersions in oils. III. Water content,purity of oils

The influence of water on the interactions between fat and sugar crystals dispersed in triglyceride (vegetable) oils was qualitatively estimated from sedimentation and rheological experiments. The experiments were performed both with and without food emulsifiers (monoglycerides and lecithins) present in the oil. The effects of minor natural oil components (nontriglycerides) on the interactions and on emulsifier adsorption to the crystals were examined by comparing a commercial refined oil and a chromatographically purified oil. The results show that water generally increases the adhesion between fat and sugar crystals in oils and also increases the surface activity of the oil-soluble food emulsifiers. Minor oil components give a small increase in the adhesion between fat and sugar crystals in oils, but do not influence the adsorption of food emulsifiers in any systematic way.     

铝型材加工氧化着色污水处理的工程实践

采用中和—加药混凝—沉淀—压滤除渣的方法处理铝型材加工氧化着色污水。出水pH值及悬浮物等指标满足《污水综合排放标准》GB8978—96中一级排放标准。改气浮法为沉淀法,采用竖流式沉淀池,简化工艺流程,缩短处理时间,节约投资与运行费用。     

石蜡沉积对储层渗透率的影响研究

油气开采过程中的蜡质、沥青质等有机固相沉积。严重影响着油田的正常生产。固相沉积物不仅堵塞油井、输油管线,而且也给油藏多孔介质造成一系列的伤害。如堵塞油藏孔隙、降低孔隙度和渗透率,改变油藏岩石的润湿性,从而影响原油采收率的提高。本文采用热力学理论建立了液固两相相平衡方程,模拟计算石蜡沉积量对储层孔隙度和渗透率影响,进而求出对油井产能的影响。