天峨水文站历史洪水首项经验频率置信区间估算

历史特大洪水加入样本系列，对提高设计洪水精度起着关键作用。但由于特大洪水的稀遇性，以及随着实测系列的延长．其经验频率又具有不确定性，给频率曲线的外延带来任意性。本文引入对首项顺序统计量置信区间估计的方法．对首位历史洪水经验频率置信区间进行估算，指导频率曲线的适点配线，对设计洪水和设计暴雨分析计算工作具有一定的实用意义。     

鄂西北“2012.8”暴雨中心最大24h降雨量重现期计算与思考

考证了南河、北河流域历史洪水及其重现期,用特大洪水经验频率代表相应的特大暴雨经验频率,将暴雨特大值与一般值组成一个不连续的暴雨资料系列,采用皮尔逊Ⅲ型(P-Ⅲ)曲线计算了湖北省房县佘家河雨量站最大24 h设计暴雨参数,以及"2012.8"最大24 h降雨量的重现期。选择代表频率的设计成果与历次计算成果比较,论证了本次暴雨设计成果的合理性。     

含特大洪水系列时经验频率计算的改进

含特大洪水系列的经验频率计算公式,现采用的主导思想是以特大洪水系列为主来修改实测洪水系列的频率,因特大洪水系列的不确定性远较实测洪水系列为大,故由此而得的公式是值得商榷的.本文建议以不确定性较小的实测洪水系列为主,结合实例,对原公式进行剖析,将特大洪水系列的经验频率给予适当调整,提出新的计算方法和公式.     

特大洪水对洪峰流量频率计算的影响

在工程设计中,洪峰流量频率计算常采用皮尔逊Ⅲ型理论频率曲线的计算方法,资料系列的长短、有无历史洪水的加入,设计结果相差较大,本文以小凌河锦州站为例,分析计算特大洪水在推求设计洪水中的作用。     

洪水频率计算中历史洪水量级划分标准探讨

特大洪水（工程设计中又习惯称为历史洪水）是指历史上或近期实测资料中比一般洪水大得多的洪水。大量事实已经证明，在实测水文资料系列较短的情况下，在频率计算中正确应用特大洪水资料，可以起到延长水文资料系列，提高资料代表性的作用，从而提高频率计算的精度。湖南省水文资料系列均较短，绝大部分测站实测资料在20～50年。洪水频率计算中，需要通过调查、考证等手段获得历史洪水资料。但这些调查洪水有的比实测的大，也有的比实测的小，那么，频率分析定量上，什么样的调查洪水和实测洪水的值可以作为特大洪水处理呢？我国现行《水利…     

对具有两组历史洪水的洪水系列均值计算公式的探讨

我国历次部颁的水利水电工程设计洪水计算规范，都规定采用与经验点据拟合良好的频率曲线估计洪水设计值。在利用年最大洪峰流量资料推求设计洪水计算中，洪水系列往往包含有数个历史洪水，属不连序系列，有时甚至涉及到多个调查考证期。在采用矩法进行其参数估算时，本文重新推导了具有两个不同调查考证期不连序洪水系列均值的计算公式。比较结果表明，本文推导的公式可获得理想的适线效果。     

再论含特大洪水系列的频率计算间题

叙述了不连序洪水系列(特大洪水和实测洪水系列)的经验频率计算、频率曲线绘制和参数 估计等问题。认为在研制方法时应以不确定性较小的事件为主,并提出了评析意见及改进的建议。由 于水文频率计算具有一定的不确定性、随机性和经验性,故需对计算结果进行综合平衡,通过合理性 分析后取用。     

稳定的常遇洪水是推求稀遇洪水的基础

较短实测洪水系列中的最大洪水属不稳定频率点据,尤其是特大值的重现期不易准确确定,若在频率适线时明显脱离多数实测洪水点据,按不确定、不稳定的特大洪水或实测最大洪水的频率点据定线,则由此推算的稀遇洪水偏差较大。当洪水系列达到一定长度、洪水系列中20年一遇以下的常遇洪水相对趋于稳定时,联动调整洪水系列的均值、CV、CS/CV,使理论频率曲线基本上通过较稳定的洪水频率点据,由此外延推估稀遇洪水,其稳定性、可靠性将增大。     

三峡水利枢纽设计洪水

三峡水利枢纽设计洪水采用三峡水利枢纽上、下游大量历史洪水碑刻、洪痕及历史文献记载，分析历史洪水的大小及重现期。连择P-Ⅱ型理论分布曲线进行频率曲线拟会，并以1954，1982，1981年实测洪水作为设计洪水典型，采用同频率组成法按峰、量同频率控制放大洪水典型年入库洪水作为入库设计洪水，反映了三峡水库建成后的实际情况。对由于系列长度不足所引起的设计洪水不确定性问题，开展了期望概率研究，得出各种时段洪量的期望概率十分接近或稍低于设计频率，均能满足工程指定的设计标准。通过对洪水随机模拟的研究，论证了由于上游干支流兴建水库对三峡工程设计洪水成果的影响和三峡水库对中下游防洪调度的巨大作用。因而为三峡水利枢纽提供了准确可靠的设计洪水成果。     

桥巩水电站设计洪水的确定

红水河桥巩水电站洪水设计时，对桥巩水电站洪水系列的插补延长和历史洪水个数比较多的不连续系列在不同的考证期内，其经验频率的计算，以及论述上游龙滩水电站对桥巩水电站坝址设计洪水的影响分析，以确定其设计洪水成果。     

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.     

设计洪水在防洪计算中的误区

在防洪计算中,设计洪水的可靠性直接影响着待建工程的规模大小、安全程度和浪费状况。本文主要阐述了影响设计洪水计算成果的几种误区：一是过多使用人造插补延长资料系列的误区;二是特大洪水插补越多越好的误区;三是面积和河长水文比拟法的选用的误区;四是无连续大洪水发生,设计洪水稳定不变的误区等。并通过对陕西省泾河上的张家山和桃园水文站流量系列进行实例分析,分别验证这四种误区的影响。     

三里坪水利枢纽工程设计洪水复核分析

南河流域洪水特性受台风雨影响,表现为洪高量大,汇流快。为了对三里坪枢纽工程验收提供设计洪水复核成果,通过对坝址附近控制站—台口（二）水文站多年实测资料分析,并进行历史洪水调查,结合历史洪水与实测洪水组成不连续系列进行频率分析,得出坝址设计洪水成果,对原有初步设计成果加以复核。复核结论认为,依据台口（二） 站计算的设计洪水成果可作为三里坪水库的设计依据。其分析计算方法可供类似工程区域设计洪水计算参考。     

潇河大坝洪水分析中对历史调查洪水的考虑

本文通过采用潇河大坝长短系列及对历史调查洪水的不同处理方式，进行潇河大坝的洪水分析计算，并对结果进行比较，提出了在设计洪水分析计算中对历史洪水考虑方式的意见和理由。     

Use of L-Moments Approach for Regional Flood Frequency Analysis in Sicily, Italy

Extremely great floods are among environmental events with the most disastrous consequences for the entire world. Estimates of their return periods and design values are of great importance in hydrologic modeling, engineering practice for water resources and reservoirs design and management, planning for weather-related emergencies, etc. Regional flood frequency analysis resolves the problem of estimating the extreme flood events for catchments having short data records or ungauged catchments. This paper analyzes annual maximum peak flood discharge data recorded from more than 50 stream flow gauging sites in Sicily, Italy, in order to derive regional flood frequency curves. First these data are analyzed to point out some problems concerning the homogeneity of the single time series. On the basis of the L-moments and using cluster analysis techniques, the entire region is subdivided in five subregions whose homogeneity is tested using the L-moments based heterogeneity measure. Comparative regional flood frequency analysis studies are carried out employing the L-moments based commonly used frequency distributions. Based on the L-moment ratio diagram and other statistic criteria, generalized extreme value (GEV) distribution is identified as the robust distribution for the study area. Regional flood frequency relationships are developed to estimate floods at various return periods for gauged and ungauged catchments in different subregions of the Sicily. These relationships have been implemented using the L-moment based GEV distribution and a regional relation between mean annual peak flood and some geomorphologic and climatic parameters of catchments.     

Flood Hydrology and Geomorphology of Monsoon-dominated Rivers: The Indian Peninsula

ABSTRACT

The rivers of the southern part of the Indian Peninsula are monsoonal in nature and the hydrological characteristics of these rivers djffer markedly from those of Himalayan rivers. The rivers are subjected to severe floods during the monsoon season. In the last few decades, several large-magnitude floods (peak floods between 10,000 and 80,000 m³/s) have been recorded. In general, floods caused by precipitation from Bay of Bengal depressions include the peak flood of record. Analyses of the systematic, historical, and paleoflood records indicate that, in recent decades, the frequency of high-magnitude floods has increased significantly. Hydraulic estimates reveal that high flows are capable of bedrock erosion and transportation of coarse material.

Such large floods are important, not only from the standpoint of geomorphic work, but also in terms of social impact. Floods in the peninsular region are responsible for colossal loss of human life, crops, and property. In recent years, various measures offlood control and management have been adopted. However, flooding in such large rivers profoundly challenges flood-hazard management, because of the inadequacy of conventional data and high spatio-temporal variability of floods. To understand flood hazards and environmental change it is imperative that engineers and hydrologists utilize historical and paleoflood records to improve risk analyses as well as to estimate probable maximum flood on rivers such as these in a highly flood-prone region.     

浅论无资料地区采用气温推求设计洪量的分析计算

随着吉木乃县城市经济的发展,洪水灾害所带来的一系列问题也愈来愈突出,群众迫切要求对拉斯特河的洪水进行治理。由于该地区处地偏远,无长系列水文资料,仅有较完整的长系列气温资料,通过分析发现径流量与降水、气温有十分密切的关系,在径流量、降水、气温的三者关系中建立了它们之间的回归方程式,对延长径流量、时段洪量进行频率计算有很大的帮助。     

Uncertainty evaluation of design rainfall for urban flood risk analysis

A reliable and long dataset describing urban flood locations, volumes and depths would be an ideal prerequisite for assessing flood frequency distributions. However, data are often piecemeal and long-term hydraulic modelling is often adopted to estimate floods from historical rainfall series. Long-term modelling approaches are time- and resource-consuming, and synthetically designed rainfalls are often used to estimate flood frequencies. The present paper aims to assess the uncertainty of such an approach and for suggesting improvements in the definition of synthetic rainfall data for flooding frequency analysis. According to this aim, a multivariate statistical analysis based on a copula method was applied to rainfall features (total depth, duration and maximum intensity) to generate synthetic rainfalls that are more consistent with historical events. The procedure was applied to a real case study, and the results were compared with those obtained by simulating other typical synthetic rainfall events linked to intensity-duration-frequency (IDF) curves. The copula-based multi-variate analysis is more robust and adapts well to experimental flood locations even if it is more complex and time-consuming. This study demonstrates that statistical correlations amongst rainfall frequency, duration, volume and peak intensity can partially explain the weak reliability of flood-frequency analyses based on synthetic rainfall events.     

万家寨引黄入晋工程设计洪水计算

引黄工程跨沟建筑物断面无实测洪水资料，其设计洪水采用暴雨法，历史洪水调查和邻近地区水文站设计洪水综合分析确定，历史洪水调查和邻近地区水文站设计洪水的地区综合对提高设计洪水的合理性和可靠性有重要的作用。