谈罗夫河上游水土流失治理对策

对罗夫河上游水土流失形成的原因、危害进行了全面详细的分析,提出了切实可行的治理措施和对策,并经实践证明,治理后的区域初步形成了水土保持生态防护体系,控制了水土流失,实现了水土资源的持续利用。     

黄河三角洲地区吹填土地基处理思路初探

为了解决黄河三角洲地区的吹填土地基处理问题,本文以某项工程实例为例,通过分析比较三种常用的施工方法,探讨了适合黄河三角洲地区的吹填土地基处理的最好方法。     

Effect of different land use on soil erosion in the pre-alpine fringe (North-East Italy): Ion budget and sediment yield

Data concerning ion budget from rainfall, runoff and soil loss measurements from two experimental plots located in North-East Italy, under different land cover (beech forest and vineyard, respectively), are reported. The chemical composition of rainfall, soil solution and runoff was determined to study the solute cycle within the soil, and the relationships between water, soil and vegetation. The forest ecosystem is more prone to acidification than the agricultural one; the elemental concentration of runoff water is considerably lower than that of soil solution. Comparing the ion input (rainfall) and output (runoff) at the two sites, it was possible to estimate the ion budget in the two soil-vegetation systems. The runoff amount and the ion balance are related to rainfall volumes and composition; the measured runoff under vineyard is 59% in comparison to the one under beech. The soil loss at the two experimental sites (170 kg/ha and 132 kg/ha, respectively) is quite limited. The measured sediment yield of the two catchments (0.24-0.19 t/ha/year, respectively) is consistent with data reported for native forests of western Europe. Comparing rainfall and soil loss at the two sites proved that maintenance of some form of land cover is advisable if runoff and erosion are to be minimized. In the European context, where the most important consequences of erosion are sedimentation downstream and loss of productivity, this type of data will yield valuable information for the understanding of such processes occurring at catchment scale, and will help policy-makers develop appropriate programs for the territory safeguard.     

黄河三角洲软弱土层中的深基坑支护

黄河三角洲地区土质大部分为粉质粘土,粉土,粉砂,地基土承载力较低,城市地下水位较高。本文以所承建的东胜石油公司综合楼基坑支护方案为例,介绍在黄河三角洲地区,采用钻孔灌注加锚杆加深层搅拌桩止水帷幕进行基坑支护工程的设计施工经验。实践证明,所选定的基坑支护和施工方案是成功的,具有形式简单,受力明确,支护可靠的优点,本工程基坑支护是对黄河三角洲软土条件下深基坑支护形式的一种探索,可供类似工程参考。     

黄河大堤土体三轴抗拉试验研究与应用

土体的抗拉特性与土堤裂缝的产生直接相关,因此,正确认识土的抗拉特性和准确测定抗拉强度指标就显得十分重要。在土体强度特性的研究中,过去多侧重于抗压强度和抗剪强度,对抗拉强度的研究较少。针对黄河大堤典型土质开展了三轴抗拉试验研究,得出了许多有益成果,并就具体应用方法进行了探讨。     

山东黄河冲积区杂填土地基处理实例分析

杂填土的地基处理是目前城市建设中经常面对的问题。山东黄河冲积区杂填土地基具有浅埋地下水位和杂填土下仍分布软弱土层两个典型特征,这影响着地基处理方法的选取、处理深度的设计、材料和施工机械的选择。根据本区的两个工程实例的勘察资料和建筑物特征,主要分析评价了CFG复合地基、级配砂石换填垫层法和柱锤冲扩桩复合地基3种地基处理方法处理杂填土的适用性。主要从地基处理方法的选用过程、加固机理和计算等方面总结了相关实践经验。     

植被护坡在路基边坡水土流失治理中的应用

从水土流失的诱发原因和危害入手,分析了在路基工程中植被护坡技术的作用机理、具体特点、实施方法,指出该方法在达到防护要求的同时可兼顾经济、生态环境效益,值得推广。     

The role of geosynthetics in erosion and sediment control: An overview

The use of geosynthetic erosion and sediment materials continues to expand at a rapid pace. From their early beginnings in the late 1950s, geosynthetic materials today are the backbone of the erosion and sediment control industry. Geosynthetic components are an integral part of erosion and sediment materials ranging from temporary products such as hydraulic mulch geofibers, plastic erosion control meshes and nettings, erosion control blankets and silt fences to high performance turf reinforcement mats, geocellular confinement systems, erosion control geotextiles and fabric formed revetments. This paper provides a brief overview of these materials and concepts.     

贫困的城市群带如何发展--黄河上游城镇密集区发展透视

黄河上游城市群带是指兰州、西宁两个省会城市及周围的城镇密集区 ,通过分析该城市群带的基本情况和特点 ,对发展中的问题进行透视 ,提出黄河上游城市群带的发展格局 ,探索在国家西部大开发的战略决策指引下 ,城市群带发展的目标、途径和动力机制     

内蒙古乌尔吉地区水系沉积物工作方法及应用

介绍了内蒙古乌尔吉地区的地质条件,利用水系沉积物,对该地区进行了地球化学勘查,分析了各元素在水系沉积物中的分布特征,结果显示:区内As,Ag,Bi,Zn,Pb,Sb元素相对富集且分布不均匀,有成矿可能;Cu,Au元素虽无明显富集,但有较强的分异性,也有成矿可能;赋矿地质体为晚二叠世林西组、中二叠世哲斯组。     

抽黄灌区泥沙问题的调查与思考

详细介绍了黄河小北干流泥沙淤积的特点及其对东雷抽黄灌区的危害,提出了解决泥沙问题的步骤和措施,论述了在渠首运用先进的自排沙廊道技术解决粗泥沙的重要性、可行性和必要性,以期从源头上解决粗泥沙问题。     

Sorption and accumulation of cadmium in the sediment of the Tama River

Cadmium contents in the water and the sediment samples collected from the Tama River and several branches were measured. Cadmium (above 0.005mgl⁻¹) was detected in only four of the water samples, while the sediment samples showed cadmium content of 1.0–9.8 μg g⁻¹ dry sediment. Cadmium concentration in the sediments of the main stream was correlated against ignition loss of the samples and it was found that 1 g of ignition loss (organic matter) corresponded to 35 μg of cadmium.The batch adsorption experiment in the laboratory using an aqueous solution of cadmium for 14 sediment samples with a higher concentration of cadmium indicated that the amount adsorbed by the sediment is highly dependent on the ignition loss. The amount adsorbed on unit mass of ignition loss q_IL could be correlated by a Freundlich-type equilibrium relation as where C is the equilibrium concentration in the aqueous phase ranging between 7 × 10⁻³ and 10 mg l⁻¹, while k_IL and n are equilibrium constants.The adsorption rate measurement showed that the intraparticle diffusion coefficient of cadmium in the sediment was about 1.1 × 10⁻⁶ cm²s⁻¹, which is of a reasonable order of magnitude assuming the pore diffusion mechanism inside the particle.The results suggest that suspended solid particles of high organic content in flowing water contribute significantly to the transport of cadmium along the river.     

Understanding the combined influence of fine sediment and glyphosate herbicide on stream periphyton communities

Pesticides and deposited fine sediment have independently been associated with changes in relative abundance and species richness in aquatic ecosystems, but the interplay between these two stressors in agricultural streams is poorly understood. A 28-day experiment in outdoor stream mesocosms examined the effects of four levels each of fine sediment coverage (0, 25, 75, 100%) and glyphosate-based herbicide concentration (0, 50, 200, 370 μg/L) on periphyton communities (algae and bacteria) in a fully factorial, repeated-measures design. Our aims were to determine whether (i) increased levels of sediment and glyphosate had individual and/or additive effects, (ii) increased sediment reduced the toxicity of glyphosate (antagonistic multiple stressor interaction), or (iii) sediment-adsorbed glyphosate prolonged the effects of exposure (synergistic interaction). We also assigned all algal taxa to three ecological guilds (low-profile, high-profile and motile growth forms) and separately determined their responses to the treatments. As individual stressors, sediment addition affected all algal community-level metrics, whereas glyphosate addition only affected algal community evenness. Bacterial taxon richness was unaffected by either stressor. In combination, however, significant overall sediment by glyphosate interactions were detected, demonstrating synergistic (algal evenness, high-profile and motile guilds) or antagonistic effects (low-profile guild). Our experiment underscores the importance of considering both structural and functional indicators, including algal guild representation, when assessing the mechanisms by which periphyton communities respond to multiple stressors.     

黄河泥砂-粉煤灰蒸压砖的研制

以黄河泥砂、粉煤灰为主要原料,采用化学激发方法生产蒸压砖.通过正交试验,确定了蒸压砖的最佳配比为m(泥砂):m(粉煤灰)=1:2、骨科掺量20%、水固比1:4、困料时间10 h、成型压力16 MPa,其性能达到JC 239--2001<粉煤灰砖>规定的MU20级砌墙砖的要求.     

黄河的治理开发与小浪底工程

据新华社消息,2002年10月16日黄河水 利委员会宣布,黄河首次调水调沙试验获得圆满成功。当年7月4日至15日进行的这次试验,利用小浪底水库人造洪水,以每秒 2600 m~3的大流量,持续放水11天(总用水量 11.5亿 m~3),对黄河下游这段“地上悬河”进行冲刷减淤。在原始河床上,进行如此大规模的调水调沙试验,不仅在世界水利史上是第一次,也是我国黄河治理开发的新的     

喷钢纤维混凝土在引黄工程中的试验与现场应用

本文介绍了山西万家寨引黄工程总干线一、二级泵站C40喷钢纤维混凝土的试验及现场应用的实际情况。通过实际施工应用,概括总结了几点建议和结论。     

Occurrence and risk assessment of acidic pharmaceuticals in the Yellow River, Hai River and Liao River of north China

Pharmaceuticals in the aquatic environment have received great attentions from the general and scientific community due to their potential impacts on ecological and human health. We investigated the occurrence of twelve acidic pharmaceuticals and herbicides (salicylic acid, clofibric acid, ibuprofen, gemfibrozil, fenoprofen, naproxen, ketoprofen, mefenamic acid, tolfenamic acid, diclofenac, meclofenamic acid and indomethacin) in surface waters of the Yellow River, Hai River and Liao River in north China during the wet and dry seasons and assessed the potential risks to aquatic organisms posed by these acidic compounds. Seven acidic compounds were detected in the rivers, including five non-steroidal anti-inflammatory drugs (salicylic acid, ibuprofen, diclofenac, mefenamic acid and naproxen), and two blood lipid regulators (clofibric acid and gemfibrozil). The concentrations for acidic pharmaceuticals in the Yellow River and Liao River were in most cases higher in the dry season than in the wet season, but the concentrations of acidic compounds in the Hai River were generally higher in July than in November. High concentrations of these detected compounds in the Yellow River, Hai River and Liao River were found more frequently at those sites located in metropolitan areas, lower reaches or river confluences. Only diclofenac and ibuprofen were found to have medium to high risks in the three rivers based on the calculated risk quotients.     

黄河三角洲地区黄河河床取水方法研究

通过在黄河滩地利用大口径水平辐射井取水试验 ,探讨了解决在黄河下游细颗粒含水层合理开发地下水难题的关键技术和方法。实验证明 ,大口径水平辐射井可以大幅度提高单井出水量 ,降低了以黄河水为供水水源的取水成本     

黄河下游悬河段傍河开采地下水的试验研究——以郑州市区黄河滩地为例

黄河下游频频出现的断流现象给沿岸城市的供水造成严重威胁 ,本文根据近年在郑州市北郊黄河滩地供水水文地质勘探中 ,几组大型抽水试验所获得的地质信息 ,论证了傍河地带的地下水资源潜力 ;细颗粒含水地层中的成井技术 ;傍河开采地下水可能诱发的水环境和地质环境问题。文章的结论是 :黄河下游沿岸地带 ,地下水资源十分丰富 ,大规模开采傍河地带的地下水所诱发的环境负效应十分有限 ,具有建立傍河地下水源地的优越条件。     

黄河三角洲地区桩基选型与设计

以滨州市某小区高层剪力墙结构住宅为例,以地质勘察报告为依据,结合工程所处位置的实际地质情况,详细分析了该高层住宅桩基选型与设计,结果表明,采用预制方桩是最经济、最合理的。