漏斗式全沙排沙工程试验研究及其应用

漏斗式全沙排沙设施是一种排沙耗水量小，截沙率高的泥沙处理技术，并已在工程实际应用中取得了良好的效果。本文通过其清、浑水流场特性分析表明，漏斗室内部水流特性有利于水沙分离和泥沙的排除。     

《螺旋流排沙漏斗》新技术的研究与应用

《螺旋流排沙漏斗》是经过多年系列模型试验及原型观测获得成功的。它的第一阶段成果《强螺旋流排沙漏斗》于1990年通过新疆维吾尔族自治区科委组织的国内专家鉴定，成果属国内领先水平。对粒径大于1mm的粗颗粒泥沙排除率可达100％，排沙耗水量平均低于引水量的7％。第二阶段成果《螺旋流排沙漏斗》除具有上述成果的全部性能外，尚可对粒径0．05～1mm的细颗粒泥沙排除率达90％以上，排沙耗水量降至引水量的3％～5％。     

泥沙起动判别条件和推移质输沙率

在建立考虑了泥沙起动概率因素的散体泥沙起动流速计算式的基础上，讨论了泥沙起动概率，泥沙平均起动颗粒百分数，泥沙起动流速系数和推移质输沙率之间的关系．若以沙莫夫起动流速公式对应的起动流速系数值作为沙质河床起动临界条件的约定值时，相应的泥沙起动概率为０．１２７１，床面泥沙平均起动颗粒百分数为１２．７１％，无量纲推移质输沙率Φ为０．００３３５．这些结果与实际情况是基本符合的，可作为室内或野外观测泥沙起动的定量判别条件．     

云中河灌区干渠涡管排沙原型观测

涡管排沙是一种较好的防淤减淤的排沙装置，其结构简单，布置简便，耗水少，排沙效率高。经原型试验观测，在渠道流量为０．４５～１．９ｍ￣３／ｓ、输沙率为０．１１～２．０４ｋｇ／ｓ和涡管流量为０．０４～０．０８ｍ￣３／ｓ、输沙率为０．１１～１．７７ｋｇ／ｓ的情况下，其耗水比为４．４％～１１．１％，其排沙比为５４．８％～９２．２％。即可用７％的水排除７５％以上的泥沙。排沙比还随悬浮指标的增大而提高，当悬浮比小于１．０时，排沙比仅为５０％左右；当悬浮比大于１．０时，排沙比达到８０％左右。即是说，在渠道上游，适当减小流速，使悬浮比增大，排沙比可提高。     

粉沙质海岸泥沙特性实验研究

本研究根据泥沙性质，提出了滩面泥沙中值粒径介于０．０３ｍｍ￣０．１２ｍｍ的海岩为粉沙质海岸，并对其泥沙特性进行了实验研究。结果表明，粉沙质海岸泥沙特性除了与中值料径有关外，还与级配有关。当泥沙中粘性细颗粒物质含量较高时，其整体体现淤泥质泥沙特性，当泥沙中粘性细颗粒物质含量较低时，整体体现散粒体泥沙特性，其运移形态前者是以悬移质运动为主，后者地既有悬移质运动又有推移质运动。对于推移质输沙，其输沙率不     

溪洛渡水库减缓三峡库区泥沙淤积的试验分析

在涪陵长江河段１：１５０正态模型上，进行有无溪洛渡水库沙情况下三峡水加按照１５６ｍ方案运行的系列泥沙试验证明，若修建溪洛水库，该河段泥沙淤积总量将减少５８．７％水面比降降低０．０５４％－０．０６１％，这不仅对于改善可段港区的航道条件，减少后期移民数量十分有利，而一对于改善整个三峡库尾的生态环境具有重要作用。     

河流泥沙颗粒特性对磨损影响的研究

泥沙的颗粒特性是影响泥沙磨损的重要因素之一．结合近年来有关泥沙磨损特性规律的研究，对黄河沙、长江沙、蒲石河沙和石英砂的颗粒特性、磨损特性及相互关系进行了初步探讨．对各种试验结果进行对比分析表明：（1）黄河沙、长江沙和270目石英砂3种沙粒的磨损能力差异显著，在试验流速范围内，若将石英砂的磨损能力取为1．0，则黄河沙和长江沙的磨损能力相对值（即相对于270目石英砂磨损能力的比值）分别近似为37％和28％，远小于两种河沙中的硬颗粒含量，接近或小于河沙中的石英含量；（2）由于沙粒形状对磨损的影响，几种河沙中所含石英的磨损能力小于等量的270目石英砂的磨损能力．     

三门峡库区及下游河道淤积物粒径分析

通过对三门峡库区及下游河道实测输沙资料和淤积物取样分析发现：三门峡库区及下游河道淤积物中，粒径ｄ ≥０．０５ ｍ ｍ 的泥沙含量１９５０ ～１９９５ 年为４２．３ ％ ～４４ ．５％ ，ｄ≥０ ．０２５ ｍ ｍ 的泥沙含量为７２ ．８ ％ ～７４ ．３ ％ ；从各年代不同粒径组泥沙的百分含量来看，ｄ ≥０ ．０５ ｍ ｍ 的泥沙含量从５０ 年代的５０ ．９ ％ 减少到９０ 年代的３０ ．３ ％ ，而ｄ ≥０ ．０２５ ｍ ｍ 的泥沙含量从５０ 年代的８１ ．８ ％ 减少到９０ 年代的６１ ．９ ％ ，泥沙有细化的趋势。     

渠道不同粒径组泥沙的输移特性

本以灌区实测水沙资料为基础．通过分析悬沙垂线分布，提出泥沙输送的条件，进一步分析不同粒径组泥沙的输移特性及对渠道泥沙淤积的影响。指出粗沙是造成泥沙淤积的关键．阐述不同粒径组泥沙都具有多来多排的特性．但其变化规律有所差异。通过比较多十挟沙能力公式．最后给出适应簸箕李灌区挟沙能力的具体表达式。     

温度对粘性泥沙的沉速及淤积的影响

温度对粘性泥沙的沉速及淤积的影响［加拿大］Ｙ．Ｌ．ＬＡＵ主题词沉沙沉降，沉降速度，淤积计算，沙模拟试验，水温影响引言以往关于淤积的试验分析已经研究了影响淤积率加淤积度的不同因素，包括河床剪应力、泥沙类型、水化学特性等，但对温度因素的关注却较少。在北方...     

SPATIAL AND TEMPORAL WATER QUALITY VARIABILITY IN AQUATIC HABITATS OF A CULTIVATED FLOODPLAIN

The floodplains of lowland rivers contain diverse aquatic habitats that provide valuable ecosystem services but are perturbed when intensively cultivated. Hydrologic, water chemistry and biological (fish) conditions in five aquatic habitats along the Coldwater River, Mississippi, were measured for more than 4 years: the river, two severed meanders that functioned as backwaters, a managed wetland and an ephemeral channel draining cultivated fields. Off‐channel habitats were connected to downstream regions 0.10% to 32% of the dry season and 24% to 67% of the wet season. The median temperatures for the five monitored sites ranged from 18°C to 23°C, the median total solids concentration for all sites was 135 mg L^?1, the median total phosphorus was 0.29 mg L^?1 and the median total nitrogen was 1.56 mg L^?1. Chemical and physical water quality displayed strong seasonal differences between the wet winter/spring and the dry summer/fall periods so that temporal variation consisted of gradual seasonal trends superimposed on strong diurnal variations. All off‐channel habitats exhibited periods of hypoxia and temperatures >30°C during the dry season. Between‐site gradients of water and habitat quality were strongly coupled to water depth and runoff loading. The rehabilitation of one backwater by increasing water depth and diverting agricultural runoff was associated with improved water quality and fish species richness relative to an adjacent untreated backwater. The diversion of polluted runoff and the use of water control structures to maintain greater water depth were observed to be effective management tools, but the former reduces the water supply to habitats that tend to dry up and the latter reduces connectivity. Published in 2011 by John Wiley & Sons, Ltd.     

Spatio‐temporal variation of gross CO2 and CH4 diffusive emissions from Australian reservoirs and natural aquatic ecosystems,and estimation of net reservoir emissions

Carbon dioxide (CO₂) and methane (CH₄) diffusive emissions were measured during two field surveys in Queensland and Tasmania, Australia, using the floating chamber method. Bubbling and degassing emissions in 2010 were estimated in Koombooloomba Dam reservoir using only inverted funnels and gas concentrations, respectively. A total of 14 reservoirs and 16 rivers and lakes were sampled from 2006 to 2010. Spatial variation was substantial within each water body, as well as between them. The main drivers of diffusive emission variation were physiographic region and climate, with a clear demarcation being observed between diffusive emissions from tropical Queensland and temperate Tasmania, and between the humid West Coast Range (Tasmania) and dry Central Plateau (Tasmania). Higher CO₂ and CH₄ diffusive emissions were observed during the dry season, when long water residence times would promote organic matter degradation. Estimated total gross emissions, including diffusive, bubbling and degassing emissions, for Koombooloomba Dam reservoir were about 1.5 × 10⁶ t CO₂eq km² per year, or 24 × 10⁶ t CO₂eq per year. This corresponds to a plant emission factor of 3.18 kg CO₂eq MWh^?1. Using an estimate of terrestrial emissions derived from literature data for the Tully River catchment area, rough estimated net emissions from the catchment area are about 44 kt CO₂eq per year, or 5.83 kg CO₂eq MWh^?1, which is in the lower range of the studied reservoirs.     

Serial discontinuities in a Rocky mountain river. II. Distribution and abundance of trichoptera

River regulation in the headwaters and middle reaches of the Gunnison River, Colorado, significantly altered distributions and abundances of Trichoptera fauna. Twenty-five species were collected from mainstream samples, with the greatest species richness occurring at an unregulated, rhithron segment above the central reach dams. At sites immediately below the three hypolimnial-release dams and a reregulation dam, species richness was reduced 35–90 per cent and abundance > 95 per cent. Net-spinning caddisflies were the dominant trichopterans at unregulated sites; Arctopsyche grandis in the upper reaches (218 organisms, 586 mg dry mass m^?2) and Hydropsyche cockerelli, H. occidentalis and Cheumatopsyche pettiti in the lower river (9041 total organisms, 6621 mg m^?2), downstream from the last dam. The observed distributional pattern of low trichopteran densities in dam tailwaters and high hydropsychid densities at sites 60–80 km below the central reach dams is a classic expression of continuum resets and adjustments in response to stream regulation as predicted by the Serial Discontinuity Concept.     

Surveying for Water Resources

Abstract

A professional Land Surveyor (Geomatician) describes the Hydrogeologists' survey requirements of a major water resources assessment for the government of The Sultanate of Oman (1992 to 1996). The need for objective specifications is stated. Specialist terms like geoid, spheroid, Mean Sea Level are explained and how to relate spheroidal levels to the geoid. Methods like traditional survey, satellite survey, and photogrammetry are introduced. The paper encourages coordinated working for the benefit of water resource assessment and recommends employment of the professional land surveyor for major studies.     

The Impact of Economic Development on Water Pollution: Trends and Policy Actions in Malaysia

The paper examines the impact of development activities on water pollution in Malaysia. Hence, the main objective of this paper is not just to examine the trends of development-induced water pollution around the region of the country but to know where the problems are and the policy measures taken by the government. It evaluates the probable causative relationship between problems introduced due to technology employed in water pollution control and governmental policy measures. It examines the relationship between development indicators as sources of pollution and polluted rivers over a period of 12 years. The findings of the paper have shown that despite the policy enforcement actions against the identified sources of water pollution, all the three development indicators (chosen based on those identified sources) still accounted for high percentage of river pollution in Malaysia. The findings of the paper were used to identify the central fact of the location of the problem. Some crucial conclusions of where the problems likely to be, as reflected in the findings, are: (a) the issue of interactive-effects between pollutants that many policy-makers are not aware of. This is when policy measures concentrate only on one source of water pollution; (b) the enforcement strength and/or effectiveness of policy measures themselves; (c) financial constraints to invest in appropriate technology especially sewerage systems for controlling human source of water pollution in the country; as well as those confronting small polluting industries (d) finally, lack of cooperation between government and private business firms to comply with regulatory policies for water pollution control.     

Intangible Flood Damage Quantification

Flooding is a natural disaster that may cause tremendous tangibleand intangible damage to the national economy. The tangible damage assessment, i.e. the monetary value of all direct and indirect physical damages, has already been studied, whileintangible damages have not yet been taken into account. Thisarticle, therefore, is the first systematic attempt to assess bothtangible and intangible damages. The new proposed Anxiety-Productivity and Income Interrelationgship Approach (API) has been developed to quantify the intangible damage in monetary terms. The Bangkok area has been selected as the research area because several severe flood events have occurredthere over the last two decades. The 1983 Bangkok flood caused 6600 million baht in damage, according to estimates by the National Statistical Office (NSO). This article examines the totalflood damage (including the intangible damage) at different flood magnitudes. Case studies with and without flood mitigation projects are studied and compared. Furthermore, thisarticle also discusses the improvements over the conventional approach offered by the new API methodology.     

Seasonal variation in nutrient retention during inundation of a short‐hydroperiod floodplain

Floodplains are generally considered to be important locations for nutrient retention or inorganic‐to‐organic nutrient conversions in riverine ecosystems. However, little is known about nutrient processing in short‐hydroperiod floodplains or seasonal variation in floodplain nutrient retention. Therefore, we quantified the net uptake, release or transformation of nitrogen (N), phosphorus (P) and suspended sediment species during brief periods (1–2 days) of overbank flooding through a 250‐m floodplain flowpath on the fourth‐order Mattawoman Creek, Maryland U.S.A. Sampling occurred during a winter, two spring and a summer flood in this largely forested watershed with low nutrient and sediment loading. Concentrations of NO increased significantly in surface water flowing over the floodplain in three of the four floods, suggesting the floodplain was a source of NO. The upper portion of the floodplain flowpath consistently exported NH, most likely due to the hyporheic flushing of floodplain soil NH, which was then likely nitrified to NO in floodwaters. The floodplain was a sink for particulate organic P (POP) during two floods and particulate organic N and inorganic suspended sediment (ISS) during one flood. Large releases of all dissolved inorganic N and P species occurred following a snowmelt and subsequent cold winter flood. Although there was little consistency in most patterns of nutrient processing among the different floods, this floodplain, characterized by brief inundation, low residence time and low nutrient loading, behaved oppositely from the conceptual model for most floodplains in that it generally exported inorganic nutrients and imported organic nutrients. Published in 2007 by John Wiley & Sons, Ltd.     

浅淡溢洪道改扩建方案与选择

溢洪道改扩建和进行溢洪道方案布置，要择优选取溢洪道进口型式、防冲消能工，以使其工程量省、施工快、运行管理方便     

Experience in the Introduction of Steam-Water-Oxygen Cleaning, Passivation, and Preservation at the TÉTs-23 Cogeneration Plant of the Mosénergo Company

Conditions of the process of steam-water-oxygen cleaning, passivation, and conservation (SWOC, P, and C) of internal heating surfaces of the boiler and the high-pressure feed heater (HPFH) piping over the steam side are presented. The process produces partial cleaning of the internal heating surfaces from scale and yields a corrosion-resistant protective film that hinders corrosion processes both in the operation of the boiler and in the idle period.     

钢筋混凝土三点弯曲梁断裂韧度计算模型

基于虚拟裂缝模型,针对钢筋混凝土试件在三点弯曲作用下开裂截面的受力特征,在合理假定的前提下,给出了一种计算钢筋混凝土三点弯曲梁的失稳断裂韧度的解析方法。然后,应用该方法计算了初始缝高比α0(初始裂缝长度与试件高度的比值)分别为0.2,0.3,0.4,0.5的三点弯曲试件的最大荷载和临界有效裂缝长度,进而求得了钢筋混凝土三点弯曲梁的失稳断裂韧度。通过对计算结果与试验数据的误差分析,发现失稳断裂韧度最大误差为4.915%,说明这种方法可以较为准确地预测三点弯曲梁的失稳断裂韧度。在此基础上研究了初始缝高比α0对失稳断裂韧度的影响,发现失稳断裂韧度基本上不随α0变化,失稳断裂韧度可以作为材料常数,应用于裂缝扩展状态的判断。