山区风电场50年一遇最大和极大风速估算

风电场50年一遇最大和极大风速（合称安全风速）是风电设计中的两个重要参数,受理论研究水平、资料条件等因素制约,目前尚无较为可靠的计算方法。对于山区风电场来说,地理位置、地形、资料等条件均不如平原和沿海地区,安全风速估算是山区风电场设计中的一大难点。本文通过云南某风电场的设计,以测风塔及相关气象站的实测风速资料为基础,进行了50年一遇最大和极大风速的估算分析,总结了几种较为可行的计算方法,可供相关设计人员参考。     

风电场50年一遇最大风速计算方法分析

论述风电场设计中,应用Gumbel分析法和风压法计算风电场50年一遇最大风速.分析场址空气密度下和标准空气密度下最大风速的比例关系.通过合理确定风电场50年一遇最大风速,为风电场选择安全的风机提供依据.     

青龙湾减河、潮白新河20年一遇洪水遭遇分析研究

青龙湾减河、潮白新河是天津市北部地区的重要行洪河道,是天津市北部地区的重要防洪屏障,大黄堡洼是分泄青龙湾减河洪水的蓄滞洪区,黄庄洼是分泄潮白新河洪水的蓄滞洪区。以青龙湾减河、潮白新河和大黄堡洼、黄庄洼蓄滞洪区为研究对象,开展2条河道20年一遏洪水遭遇分析,研究2条河道堤防影响和蓄滞洪区洪水演进过程,为该地区的防洪决策提供支撑,尽力减轻洪涝灾害损失。     

Effect of Extraordinary Large Floods on at-site Flood Frequency

The peak flow of extraordinary large floods that occur during a period of systematic record is a controversial problem for flood frequency analysis (FFA) using traditional methods. The present study suggests that such floods be treated as historic flood data even though their historical period is unknown. In this paper, the extraordinary large flood peak was first identified using statistical outlier tests and normal probability plots. FFA was then applied with and without the extraordinary large floods. In this step, two goodness-of-fit tests including mean absolute relative deviation and mean squared relative deviation were used to identify the best-fit probability distributions. Next, the generalized extreme value (GEV), three-parameter lognormal (LN3), log-Pearson type III (LP3), and Wakeby (WAK) probability distributions were used to incorporate and adjust the extraordinary large floods with other systematic data. Finally, procedures with and without historical adjustment were compared for the extraordinary large floods in terms of goodness-of-fit and flood return-period quantiles. The results of this comparison indicate that historical adjustment from an operational perspective was more viable than without adjustment procedure. Furthermore, the results without adjustment were unreasonable (subject to over- and under-estimation) and produced physically unrealistic estimates that were not compatible with the study area. The proposed approach substantially improved the probability estimation of rare floods for efficient design of hydraulic structures, risk analysis, and floodplain management.     

基于分洪设施的河道中小洪水生态调度

为充分利用雨洪水资源,实现河道在洪水过程中的生态安全,在分析河道生态需水量的基础上,设定河道生态水力要素阈值,并以此为约束条件,以行洪阶段河道流量与生态流量差值最小为目标,建立了河道水系生态调度模型。以济南市腊山分洪道和兴济河为例,根据实测降雨径流资料对中小洪水过程进行生态调度模拟,通过模型计算得到了闸群的最优下泄曲线,满足了城市河道在行洪阶段的生态流量要求与在蓄洪阶段的生态蓄水要求。     

小清河分洪区洪水影响的二维模拟研究简

在收集地形及水文资料的基础上,对小清河分洪区的水流运动进行了二维数值计算,分析了分洪区洪水的运动特性、淹没情况及涿州市防洪圈建设对分洪区蓄滞洪的影响。     

防护堤建设对典型洪水及防洪的影响

采用平面二维水沙数学模型,针对现状、"两滩一区"和防护堤3种河道边界条件,分别对6个量级典型洪水进行了模拟计算,分析不同边界对洪水位、淹没范围和灾情损失的影响。结果表明:现状方案有利于滩区参与河道行洪滞洪,但生产堤拆除阻力非常巨大;防护堤方案淹没面积和人口明显减少,对滩区未来发展将起到全面支撑作用,但建设周期较长、难度较大;"两滩一区"方案能够适当减小淹没面积和人口,且基本维持现状防洪格局不变,工程量较小,地方建设的积极性高,建议作为近期试点方案尽快推进。     

Uncertainty Analysis of Flood Control Design Under Multiple Floods

Hydraulic engineerings built on tributaries at the confluence of main and branch streams are significant to river management and runoff regulation. The Flood Control Design Level (FCDL) calculations for these works are directly influenced by tributary floods and supporting effects from the mainstream. However, the determination of design level under main and tributary floods has not been well investigated. To address this issue, the authors proposed a Copula-based approach to analyze the design level under multiple runoff discharge with a case study of the Guiping Shipping Hub(GPSH). The proposed method is compared with the conventional multivariate hydrological elements analysis approach, and the sampling uncertainty is also studied. The results showed that the joint distribution of main and tributary floods is well modeled by Clayton Copula, with PE3s as the best-fit marginal distributions. Furthermore, the different roles of main and branch fluxes in design level calculation can be identified by the offered Flood Control return period(FCRP). And the design levels conducted by the FCRP can avoid the situation over-or-under performed by the OR or AND RP. Moreover, flood combinations uncertainty analysis indicates that the uncertainty of the joint design combinations decreases with the increase of sample size n but increases with the rise of the design T. Finally, the 95% confidence interval and standard deviation of the design level calculated by FCRP are smaller than that of OR RP, which means the FCRP can reduce uncertainty under multiple floods. These results suggest that the proposed FCRP provides an appropriate approach for determining the design level under combined fluxes and serves as a reference for engineering practice.

     

东平湖分洪运用调度分析

介绍了东平湖分洪闸的基本情况及分洪运用的基本限制条件,对其运用调度进行了分析,结论认为:①分洪闸的运用应遵循"先老湖、后新湖"的原则,凡是仅靠老湖即能满足防洪需要的,坚持不用新湖;②分洪闸的运用应充分考虑和利用八里湾闸这一条件,保证二级湖堤安全,避免对其实施破除;③当需要向新湖分洪时,应根据实际情况,充分考虑水情以及给湖区造成的损失,在确保防洪安全的前提下尽可能减少淹没损失;④运用调度中应考虑分洪闸的校核流量,在一定条件下使用分洪闸的校核流量可以减少经济损失.     

对黄河1662年洪水及特大洪水分型的再认识

关于黄河1662年洪水,有大量的历史文献记载,但经多次调查均未发现其洪水痕迹。王涌泉认为该次洪水由台风暴雨形成,并以地方志记载的雨情为基础估算出陕县站1662年洪水的洪峰流量为47 600~58 600 m3/s,该估算结果因其太大而令人难以置信。本次研究认为该年洪水由典型的特大华西秋雨形成,遂以之为指导并以清代时任河道总督朱之锡所著《河防疏略》及有关县志记载的雨情、水情、灾情为基础,估算黄河1662年洪水陕县和花园口的洪峰流量分别为25 000 m3/s和28 000 m3/s,花园口流量超过10 000 m3/s的历时长达40多d,致使其超万洪量比以往规划设计采用的按万年一遇洪水所求的超万洪量大出约58%。以往对黄河特大洪水的分型,只考虑了发生在伏汛期的上大型、下大型和上下较大型这三种类型,没有考虑秋汛期洪水,根据本次对黄河1662年洪水的估算结果,认为黄河下游特大洪水的分型应增加华西秋雨造成的上大型洪水,使黄河下游洪水分型更为合理,并有助于促进黄河治河方略和防洪工程布局的完善,确保黄河长治久安。     

西江引水工程防洪评价报告的编制

河道管理范围内建设项目种类较多,该文以西江引水工程为实例,介绍对取水工程及穿堤、穿河工程如何分别进行防洪评价,提出不同类型工程评价具有不同的侧重点。     

导流泄洪洞泄洪消能问题研究

导流泄洪洞是水电站建设中的重要建筑物,通常单宽流量较大,佛氏数较低。通过模型试验研究了一个具体工程的导流洞消能问题,该导流洞后期还要改为泄洪洞,属典型的"龙抬头"式泄洪洞。要求出口消能工既要满足导流期的消能问题,又要满足正常运行期的泄洪消能要求。通过多种方案的试验研究,最终提出了一种结构简单、施工方便的综合式消能工。从而圆满地解决了该导、泄"二合一"隧洞出口消能工体型选择及泄洪消能问题。     

花园口水文站实测大洪水发生频次分析

花园口水文站是黄河下游洪峰编号的依据站。该站不同量级洪水的发生频次，特别是１００００ｍ＾３／ｓ以上洪水的发生频次，一直是防汛部门和大众媒体关注的焦点。在对１９４９年以来花园口水文站实测洪水资料进行系统整理的基础上，善后对１００００ｍ＾３／ｓ以上洪水的发生次数进行了分析、论证，最后得出结论：１９４９￣１９９９年花园口水文站在伏秋大汛中共发生１８６次洪峰流量大于４０００ｍ＾３／ｓ的洪水，其中洪峰流量大