故园情

置身于喧嚣的都市,眼里尽是灰色的楼群、飞驰的汽车、步履匆匆的行人,头顶是一线灰蒙蒙的天空,鼻孔里进出着污浊的空气,耳朵里充斥着无穷无尽的噪音,不由得使人常常想起家乡世外桃源般宁静的小山村.幽幽南山之下,四围山色之中,绿树掩映里,错落几户人家,潺潺溪水穿村而过,但闻鸡犬声,而无车马喧.家家养一两头牛羊,种两三亩薄田,务三四畦青菜,点四五架黄瓜.目之所及尽是青山绿水,两袖一甩,俱是明月清风.这就是我生于斯长于斯的家园.     

陈进副院长荣获湖北省环境保护政府奖

<正>2015年6月2日,在世界环境日来临之际,湖北省政府在洪山礼堂隆重召开大会表彰获得2015年"湖北省环境保护政府奖"的9个集体和6个个人,省政府、省人大和省政协领导共同为获奖集体和个人颁发了奖牌、奖章和证书。由长江水利委员会推荐,经湖北省环境保护政府奖评审委员会和环境奖评审领导小组先后评审、现场考察、审定和公示后,长江科学院副院长陈进获此殊荣。近10 a来,陈进副院长积极从事水资源及水环境保护科学普及工作,相关研究成果获得3项省部级以     

北京的母亲河上亟需实现"人水和谐"

1 永定河是北京的母亲河 1.1 北京城座落在永定河的洪积冲积扇上 洪荒时代,源自黄土高原的永定河,经过今天的山西、内蒙古、河北,咆哮而来,从上游携带的大量泥沙由于河道纵坡变缓而沉积.地势上西北高东南低,崇山峻岭从西北部缓缓倾斜,不断向东南延伸.燕山、太行山2条山脉在昌平南口的官沟交汇,形成一个向东南展开的状如围屏的弧形大山湾,地理学上称之为"北京湾".在其东南平原上,蜿蜒汇流着北京的5大水系:永定河、拒马河、温榆河、潮白河、泃河.其中以永定河最大,北京所在的平原就是在永定河洪积冲积扇的基础上形成的.从3000多a前的燕都蓟城,到852 a前的金中都城:从700多a前的元大都城到明清北京城,城址虽有所变迁,但都无一例外地建在永定河的洪积冲积扇上.     

抢险小水电贡献大作用——水利部抗震救灾阿坝工作组水电站抢险纪实

对于灾区人们来说,突如其来的强烈地震,是一段难以抹去的黑色记忆,他们凄迷的眼神,太多地渴盼光明和温暖.电--是他们重建家园的力量泉源.     

致深入抗震救灾第一线水利干部职工的慰问信

奋战在水利抗震救灾第一线的广大干部职工: 2008年5月12日14时28分,四川汶川发生了8.00级特大地震,给灾区人民的生命财产造成了巨大损失.在这场突如其来的地震灾害面前,广大水利干部职工与党中央、国务院和全国人民共同抗击,共克时艰.     

非大修期间对立式同步电动机油冷却器的漏水处理

1 基本情况 江苏省泗阳第一抽水站属于南水北调第四梯级站.该站装有TDTF-500/120-16/32立式同步电动机(可逆式)20台套.由于建站时间早,运行时间长,且冷却用水又常受到水质、水中微生物以及供水方式、压力等因素的影响,导致部分机组油冷却器水管产生不同程度的渗漏.而油冷却器水管一旦发生破裂漏水,特别是上油缸漏水,由于负压的存在,易产生虹吸现象,将油缸内的润滑油吸出,进而造成散热、润滑的中断,直至出现烧瓦.     

灾难降临我们感同身受——"5·12"四川汶川地震见闻

5月12日下午14时28分,正是中国三峡总公司成都基地相关部门职工上班时间.突然,大家都感觉到门窗哗哗作响,办公楼和公寓楼在剧烈震动,办公楼的天花板不断有物体下落,旋即停电,人们一片惊慌,纷纷跑出大楼.     

对构建和谐灌区建立减轻农民水费负担新机制的探讨

文章结合洛惠灌区近年来的工作经验,认为在社会主义市场经济深入发展的新形势下,"减负"必须遵循市场规律、价值规律,正确理解和区分农民合理负担和不合理负担,多管齐下,综合治理,既要有行政的手段,更要有法制的手段、经济的手段,大胆实践,建立科学的减负新机制,才能从根本上解决农民负担过重的问题.     

论述摘登

不要让民勤成为第二个罗布泊,这不仅仅是民勤一个地区的问题,更表达了国家改善生态环境的决心和意志. --中共中央政治局常委、国务院总理温家宝参加十一届全国人大一次会议甘肃代表团的审议时说     

山区梯田集成配套小型水工程的和谐性分析模型

针对山区梯田集成配套小型集引蓄排水工程的建设和运行使用,对因与工程区自然、人文社会经济环境不和谐,导致效益低下,土地、资金大量浪费,工程难以实现其期望价值等问题进行了分析.按工程与自然环境、人文社会相互耦合这一广义的复合系统观念,建立了一与梯田集成配套的小型水工程和谐性的分析模型,并在贵州毕节地区的实际工程中进行了应用.     

三孤立波的斜坡爬高特征

该文采用推板式造波机和改进的Goring造波方法在波浪水槽中生成了由三个等波高孤立波组成的波列,首先在坡度为1/10的斜坡上进行了多个孤立波连续爬高的实验研究。实验测量了等波高双孤立波和三孤立波在等水深波浪水槽中传播和在斜坡上的爬高过程,给出了沿程多点浪高仪测量的波面时间序列和高速摄像记录的水线在斜坡上爬高与回落过程影像。分析了来波相对波高和无量纲波峰间距对每个孤立波爬高放大系数的影响。在基于RANS方程和VOF方法的数值波浪水槽中,模拟了三孤立波爬高过程,给出了最大爬高与破碎特征。实验和数值模拟结果表明,孤立波在斜坡上回落时会产生强劲的回流水流,该反向流动导致后随孤立波破碎,消耗波动能量,使得后随孤立波的爬高放大系数明显小于没有回落水流影响的首个孤立波的爬高放大系数。当孤立的波峰间较大时,若来波相对波高较小,后两个的孤立波爬高基本相同;若来波相对波高较大时,第三个孤立波的爬高大于第二个孤立波的爬高。     

Wave runup simulations using Lagrangian blocks on Eulerian mesh

The runup of breaking and non-breaking solitary waves on a plane beach has been simulated using the shallow-water equations and a Lagrangian blocks on Eulerian mesh (LBEM) method. The results obtained for the entire range of wave steepness are compared with the experimental data, the nonlinear theory, and the finite-difference method. The LBEM simulation agrees with the nonlinear theory when the amplitude of the wave is small. On the whole, it produces a better result in agreement with the experimental data when friction is included in the simulation. The simulation also produced better result than the finite-difference simulation.     

Run-up of non-breaking double solitary waves with equal wave heights on a plane beach

The evolution and run-up of double solitary waves on a plane beach were studied numerically using the nonlinear shallow water equations(NSWEs) and the Godunov scheme. The numerical model was validated through comparing the present numerical results with analytical solutions and laboratory measurements available for propagation and run-up of single solitary wave. Two successive solitary waves with equal wave heights and variable separation distance of two crests were used as the incoming wave on the open boundary at the toe of a slope beach. The run-ups of the first wave and the second wave with different separation distances were investigated. It is found that the run-up of the first wave does not change with the separation distance and the run-up of the second wave is affected slightly by the separation distance when the separation distance is gradually shortening. The ratio of the maximum run-up of the second wave to one of the first wave is related to the separation distance as well as wave height and slope. The run-ups of double solitary waves were compared with the linearly superposed results of two individual solitary-wave run-ups. The comparison reveals that linear superposition gives reasonable prediction when the separation distance is large, but it may overestimate the actual run-up when two waves are close.     

Performance of a data-driven technique applied to changes in wave height and its effect on beach response

In this study the medium-term response of beach profiles was investigated at two sites: a gently sloping sandy beach and a steeper mixed sand and gravel beach. The former is the Duck site in North Carolina, on the east coast of the USA, which is exposed to Atlantic Ocean swells and storm waves, and the latter is the Milford-on-Sea site at Christchurch Bay, on the south coast of England, which is partially sheltered from Atlantic swells but has a directionally bimodal wave exposure. The data sets comprise detailed bathymetric surveys of beach profiles covering a period of more than 25 years for the Duck site and over 18 years for the Milford-on-Sea site. The structure of the data sets and the data-driven methods are described. Canonical correlation analysis(CCA) was used to find linkages between the wave characteristics and beach profiles. The sensitivity of the linkages was investigated by deploying a wave height threshold to filter out the smaller waves incrementally. The results of the analysis indicate that, for the gently sloping sandy beach, waves of all heights are important to the morphological response. For the mixed sand and gravel beach, filtering the smaller waves improves the statistical fit and it suggests that low-height waves do not play a primary role in the medium-term morphological response, which is primarily driven by the intermittent larger storm waves.     

一般密度分布的分层流体中内孤立波三阶理论

在浅水假定下,可以用KdV方程描述一阶内孤立波演化,其单个孤立波解有熟知的“Sech”波形,波速与波幅呈线性关系,波长与波幅的平方根成反比。本文借助计算机代数软件一MATHEMATICA,这种理论推广到三阶,得知高阶项满足线性化非齐次KdV方程,并得到波形和波速的三阶修正以及波长的二阶修正。在Boussinesq近似下讨论了有线性基本剪切流动与不变的Brunt-Vaeisalae频率这一特殊情形。     

NUMERICAL SIMULATION OF SOLITARY WAVE RUN-UP AND OVER-TOPPING USING BOUSSINESQ-TYPE MODEL

In this article,the use of a high-order Boussinesq-type model and sets of laboratory experiments in a large scale flume of breaking solitary waves climbing up slopes with two inclinations are presented to study the shoreline behavior of breaking and non-breaking solitary waves on plane slopes.The scale effect on run-up height is briefly discussed.The model simulation capability is well validated against the available laboratory data and present experiments.Then,serial numerical tests are conducted to study the shoreline motion correlated with the effects of beach slope and wave nonlinearity for breaking and non-breaking waves.The empirical formula proposed by Hsiao et al.for predicting the maximum run-up height of a breaking solitary wave on plane slopes with a wide range of slope inclinations is confirmed to be cautious.Furthermore,solitary waves impacting and overtopping an impermeable sloping seawall at various water depths are investigated.Laboratory data of run-up height,shoreline motion,free surface elevation and overtopping discharge are presented.Comparisons of run-up,run-down,shoreline trajectory and wave overtopping discharge are made.A fairly good agreement is seen between numerical results and experimental data.It elucidates that the present depth-integrated model can be used as an efficient tool for predicting a wide spectrum of coastal problems.     

两层模式下内波K-dv方程的频散关系

为了更好地了解内孤立波的特性，分别利用椭圆余弦波方法和摄动展开方法，对两层模型下内孤立波K-dv方程的频散关系进行了推导。结果显示：利用后一种方法得到的两层模式下内孤立波K-dv方程的频散关系是一种方便、实用的解析式。据此解析式可进一步得到内孤立波半波宽度与内波波数间的关系，从而可将内孤立波理论与内波合成孔径雷达（SAR）图像联系起来。用此解析式计算得到的内孤立波频率和相速度与实测结果具有很好的一致性，因而为进一步进行分析和利用数据估计内孤立波的部分参数提供了理论依据。对解析式中频散项和非线性项量级的进一步分析认为，非线性项的作用在从SAR图像中提取内波振幅等参数时最好不予忽略。     

THE FREQUENCY MODULATION OF SHORT WAVES BY NON-UNIFORM VELOCITY FIELDS

l.INTRODUCTlONScientistshavelongbeentryingtounderstandthemechanicsofocean,particularlythemotionofwaves,currentsandtides.Inthepastthemainreasonforthisscientificpursuithasbeenthesafetyofships.Recently,incoastalandoffshoreengineering,someurgenttaskshavebeenencountered:thedesignofoffshoreoilrigs,problemsofcoastalerosionandimpact,inshoreandoffshorepollutiontransportation,andsoon.Therecentdevelopmentinremotesensingtodetect,fromSyntheticApertureRadar(SAR),radarwavesBragg-scat-teredbythesea'sfr…     

孤立波作用下组合型港池共振响应的数值研究

港池受到孤立波入射时会在港池内激发多种模态的共振响应。为进一步研究不同平面布置形式港池的响应特性和共振规律,建立不同内外港池长度和连接位置的组合型港池,采用基于Boussinesq方程的波浪数值模型MIKE 21-BW模拟了孤立波作用下组合型港池的共振响应,对数值模拟的结果进行频谱分析和波幅分布测定并与现有理论值比较。结果表明,孤立波正向入射组合型港池激发的主要响应模态的频率和与其长度相等的细长港池的理论固有频率接近,各主要共振模态的振幅与内外港池的长度和两港池口门的距离有密切关系;波浪入射方向和港池内边界反射条件的改变对狭长组合型港池中形成的各共振模态的形状影响不大,但是增大港池宽度会使港池内激发明显的横向共振。最后提出了消减港湾共振的平面布置形式,可为实际工程设计提供指导。     

斜向和多向波浪的破碎指标研究

该文通过水池物理模型实验,研究了在1:15的斜坡条件下斜向和多向波浪中破碎的特点。根据波浪类型和岸坡条件将破碎指标分为四类,总结了每一类破碎指标公式的通用形式和系数。对实验中正向和斜向规则波、正向和斜向不规则波、正向和多向不规则波的破碎指标进行了比较和分析。研究结果表明:同等条件下,斜向波的破碎指标较正向波偏大,基于不规则波有效波高的破碎指标小于规则波的,而多向波在波高较大时的破碎波高与正向不规则波相比偏小。