共查询到17条相似文献，搜索用时 250 毫秒
1.
洪泽湖历史洪水分析(1736─1992年) 总被引：2，自引：0，他引：2
根据1736－1911年文献记载的洪泽湖年最高水位及1914－1992年湖区水文测站的水位、流量资料，进行了长、短序列的入湖洪峰流量及不同时段洪量的频率分析，进而推求出不同重视期的设计入湖洪量和洪水年份相当的重现期，并分析洪水的灾害特征，结果表明：1）洪泽湖历史上洪水发生频繁，1786、1851、1906年均发生过特大洪水，高堰志桩分别至163、23．4、16．1尺。2）1953年建库后，湖水位上升。年最高水位历年平均值较建库前升高了1．22m；多年平均水位升高了1．72m。3）1916－1992年淮河蚌埠站年入湖洪峰流量、最大3日洪量、最大30日洪量和年平均流量频率分析显示。1954年分别相当于20、20、45．5和30．3年一遇洪水。1991年分别相当于7．1、7．1、10和14．7年一遇洪水。1991年洪水总体上小于1954年，但灾情超过1954年．表明湖区受灾程度有加剧趋势。 相似文献
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应用新安江-海河模型研究下垫面变化对设计洪水的影响 总被引：1，自引：1，他引：0
为了探明流域产汇流参数变化特征及其演变机理,分析流域下垫面条件变化对设计洪水的影响.通过新安江海河模型研究卫河流域代表区下垫面变化情况,采用综合线性权重法对元村集站设计洪水资料系列进行一致性修正.结果表明:自由水蓄水容量、河网水流退水系数、地表填洼蓄水能力和地下水库出流初始水深这4个参数在1980年后都变大,可见代表区下垫面1980年前、后发生了明显的变化,导致流域内径流量大幅减少;合河—新村—五陵区间在1980年前15场洪水和1980年后32场洪水的预报径流深合格率都超过80%,达到乙等精度;元村集站最大5日洪量修正后比修正前平均减小27.1%;最大15日洪量修正后比修正前平均减小25.4%;最大30日洪量修正后比修正前平均减小23.0%.本研究可为水利工程的建设规模的确定提供科学依据,保障地区的防洪安全,满足人民生活和生产用水需求. 相似文献
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复杂河道洪水预报系统研究——以淮河王家坝至小柳巷区间流域为例 总被引：2，自引：1，他引：1
随着社会经济的快速发展,洪水灾害造成的损失日益严重.洪水预报作为一项重要的防洪非工程措施,对防洪、抗洪工作起着至关重要的作用.淮河洪水危害的严重性和洪水演进过程的复杂性使得淮河洪水预报系统的研究长期以来受到高度重视.本文以王家坝至小柳巷区间流域为例,以河道洪水演算为主线,采用新安江三水源模型进行子流域降雨径流预报,概化具有行蓄洪区的干流河道,进行支流与干流、行蓄洪区与干流的洪水汇流耦合计算,采用实时更新的基于多元回归的方法确定水位流量关系,并以上游站点降雨径流预报模型提供的流量作为上边界条件、以下游站点的水位流量关系作为下边界条件,结合行蓄洪调度模型,建立具有行蓄洪区的河道洪水预报系统,再与基于K-最近邻(KNN)的非参数实时校正模型耦合,建立淮河中游河道洪水预报系统.采用多年资料模拟取得了较好的预报效果,并以2003和2007年大洪水为例进行检验,模拟结果精度较高,也证明了所建预报系统的合理性和适用性. 相似文献
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与传统确定性预报相比，洪水概率预报能够为防洪调度决策提供更为丰富的信息。以大渡河猴子岩水库以上流域为研究区，建立新安江次洪模型，并采用动态系统响应曲线进行实时洪水预报校正。在确定性预报校正基础上，建立基于水文不确定性处理器（HUP）的次洪概率预报模型，定量分析预报不确定性，实现入库洪水概率预报。结果表明：(1)利用猴子岩流域2009 2019年水文气象资料，建立的新安江次洪模型整体精度较高，率定期和验证期的洪量和洪峰相对误差均在±20%以内，平均确定性系数分别为0.69和0.72；经动态系统响应曲线校正后，洪峰和洪量误差均有降低，率定期和验证期的确定性系数分别提高0.13和0.09。(2)以2020年3场洪水未来48 h预报降雨为输入，新安江模型预报精度不高，且随着预见期增长而降低，但经动态系统响应曲线校正后，整体预报精度有所提高，洪量相对误差减小幅度超50%，确定性系数提高幅度超60%。(3)HUP次洪概率预报模型提供的分布函数中位数Q50的预报精度在一定程度上优于校正后的确定性预报；提供的90%置信区间覆盖率均在90%左右，离散度均在0.40以下，能以相对较窄的区间覆盖大部分实测值... 相似文献
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变化环境下珠江流域洪水频率变化特征、成因及影响(1951-2010年) 总被引：4，自引：0，他引：4
气候变化和人类活动导致珠江流域水文变化,变化前后洪水频率分布显著不同.运用滑动秩和(Mann-Whitney U test)结合Brown-Forsythe、滑动T、有序聚类和Mann-Kendall检验法,并用累积距平曲线法获取年最大流量序列详细信息,综合确定样本最佳变化节点,并对水文变化成因做了系统分析.在此基础上,对整体序列、变化前后序列用线性矩法推求广义极值分布参数以及不同重现期设计流量.结果表明:(1)西江大部以及北江流域最佳变化节点在1991年左右;东江流域最佳变化节点与该流域内3大控制性水库建成时间基本吻合;(2)变化后,西江、北江年最大流量持续增加,洪峰强度增大,尤其是西江干流年最大流量显著增加;东江流域年最大流量显著减小,洪峰强度降低;(3)变化后,西江与北江洪水风险增加,尤其是下游珠三角地区本身受人类活动显著影响,加之西江与北江持续增加的洪水强度,珠三角地区发生洪水的强度及频次加剧,而东江洪水风险减小.此研究对于珠江流域在变化环境下的洪水风险评估与防洪抗灾具有重要意义. 相似文献
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淮河流域洪水极值非平稳性特征 总被引：1，自引：1，他引：0
基于淮河流域9个水文站的月径流量数据,采用Pettitt非参数检验法、GAMLSS模型与洪水频率分析模型等方法,揭示了淮河中上游洪水频率的演变规律,分析基于平稳性和非平稳性条件下的洪水发生强度及洪涝灾害所带来的影响.研究发现:潢川、横排头和蚌埠站点未发生明显变异,其余6个站点发生均值或方差变异,变异时间主要集中在2000年左右.淮河流域的最优拟合分布函数是Weibull;班台、蒋家集和横排头站适宜于非平稳性模型,其余站点选择平稳性模型.各站点非平稳性条件下10年和20年一遇设计流量值与平稳性条件下皮尔逊Ⅲ型分布设计流量值相差不大,但30年一遇、50年一遇和100年一遇的设计流量相差逐渐变大.横排头站和蚌埠站洪水放大因子随着时间增加呈上升趋势且大于1,百年一遇重现期不足80年.各站点年最大洪峰流量与淮河流域、安徽省水灾面积通过了95%或99%的显著性检验. 相似文献
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洪涝灾害是世界主要自然灾害之一,优化洪水预报方案对防洪决策至关重要,然而传统水文模型存在参数多、调参受人为因素影响,泛化能力弱等问题。针对上述问题,本文提出基于改进的鲸鱼优化算法和长短期记忆网络构建自动优化参数的WOA-LSTM模型,通过优化神经网络结构进一步增强该模型的稳定性和精确度,并且建立不同预见期下的洪水预报模型来分析讨论神经网络结构与预报期之间的关系。以横锦水库流域1986—1997年洪水资料为例,其中以流域7个雨量站点的降雨以及横锦站水文资料为输入,不同预见期下洪水过程作为输出,以1986—1993年作为模型的率定期,1994—1997年作为模型的检验期,研究结果表明:(1)以峰现时差、确定性系数、径流深误差和洪峰流量误差作为评价指标,相比较于LSTM模型和新安江模型对检验期的模拟结果表明WOA-LSTM模型拥有更高的精度、预报结果更稳定;(2)结合置换特征值和SHAP法分析模型特征值重要性,增强了神经网络模型的可解释性;(3)通过改变神经网络结构在一定程度避免由于预见期增加和数据关联性下降而导致的模型预报精度下降的问题,最终实验表明该模型在预见期1~6 h下都可以满足横锦水库的洪水预报要求,可以为当地的防洪决策提供依据。 相似文献
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洞庭湖三口洪峰流量和水位变异特性分析 总被引：1，自引：1，他引：0
近几十年来,受荆江裁弯、葛洲坝工程运用、三峡水库拦蓄调度、洞庭湖治理以及长江上游水土保持措施等因素的综合影响,洞庭湖三口(松滋口、太平口和藕池口)的水文情势发生了显著变化,给湖区防洪、水资源、水生态、水环境等造成一系列影响.为了深入认识三口洪水发生的复杂变化,本文采用水文变异诊断系统和Zivot-Andrews结构突变单位根检验方法,对三口各水文站点的年最大洪峰流量和年最高洪峰水位序列进行变异诊断,并对其变异特性和变异原因进行分析.结果表明,各站点洪峰流量序列的变异具有较好的一致性;受分流能力变化和上游来流变化的影响,三口各站点的洪峰流量多呈现方向向下的趋势变异;受到洪道冲刷、流量减小、顶托减弱、洪道上下游落差增大的影响,三口各站点洪峰水位在2004年均发生方向向下的跳跃变异. 相似文献
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以太湖上游西苕溪流域为研究对象,通过分布式水文模型HEC-HMS模拟次降雨洪水过程:采用可视化数据存储系统HEC-DSS建立水文气象数据库,利用Geodatabase地理数据库技术集成流域自然属性数据库,通过距离平方倒数法对雨量数据进行空间插值,SCS曲线数法计算水文损失,运动波法计算直接径流与河道洪水演进,选用基流指数退水法模拟流域基流,并对模型中水库模拟部分进行适当修正.经模型校验,模拟结果表明,计算流量与观测流量拟合较好,效率系数大于0.8,洪峰流量误差低于4%,峰现时间误差低于2 h,该模型在土地利用变化对洪水水文要素的影响研究方面有较好的应用前景. 相似文献
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Sophal Try Shigenobu Tanaka Kenji Tanaka Takahiro Sayama Maochuan Hu Ty Sok Chantha Oeurng 《水文研究》2020,34(22):4350-4364
Projecting changes in the frequency and intensity of future precipitation and flooding is critical for the development of social infrastructure under climate change. The Mekong River is among the world's large-scale rivers severely affected by climate change. This study aims to define the duration of precipitation contributing to peak floods based on its correlation with peak discharge and inundation volume in the Lower Mekong Basin (LMB). We assessed the changes in precipitation and flood frequency using a large ensemble Database for Policy Decision-Making for Future Climate Change (d4PDF). River discharge in the Mekong River Basin (MRB) and flood inundation in the LMB were simulated by a coupled rainfall-runoff and inundation (RRI) model. Results indicated that 90-day precipitation counting backward from the day of peak flooding had the highest correlation with peak discharge (R2 = .81) and inundation volume (R2 = .81). The ensemble mean of present simulation of d4PDF (1951–2010) showed good agreement with observed extreme flood events in the LMB. The probability density of 90-day precipitation shifted from the present to future climate experiments with a large variation of mean (from 777 to 900 mm) and SD (from 57 to 96 mm). Different patterns of sea surface temperature significantly influence the variation of precipitation and flood inundation in the LMB in the future (2051–2110). Extreme flood events (50-year, 100-year, and 1,000-year return periods) showed increases in discharge, inundation area, and inundation volume by 25%–40%, 19%–36%, and 23%–37%, respectively. 相似文献
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Bivariate flood frequency analysis using the copula function: a case study of the Litija station on the Sava River 总被引：3，自引：0，他引：3 
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下载免费PDF全文 As an alternative to the commonly used univariate flood frequency analysis, copula frequency analysis can be used. In this study, 58 flood events at the Litija gauging station on the Sava River in Slovenia were analysed, selected based on annual maximum discharge values. Corresponding hydrograph volumes and durations were considered. Different bivariate copulas from three families were applied and compared using different statistical, graphical and upper tail dependence tests. The parameters of the copulas were estimated using the method of moments with the inversion of Kendall's tau. The Gumbel–Hougaard copula was selected as the most appropriate for the pair of peak discharge and hydrograph volume (Q‐V). The same copula was also selected for the pair hydrograph volume and duration (V‐D), and the Student‐t copula was selected for the pair of peak discharge and hydrograph duration (Q‐D). The differences among most of the applied copulas were not significant. Different primary, secondary and conditional return periods were calculated and compared, and some relationships among them were obtained. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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《水文科学杂志》2012,57(15):1867-1892
ABSTRACTThe flood peak is the dominating characteristic in nearly all flood-statistical analyses. Contrary to the general assumptions of design flood estimation, the peak is not closely related to other flood characteristics. Differentiation of floods into types provides a more realistic view. Often different parts of the probability distribution function of annual flood peaks are dominated by different flood types, which raises the question how shifts in flood regimes would modify the statistics of annual maxima. To answer this, a distinction into five flood types is proposed; then, temporal changes in flood-type frequencies are investigated. We show that the frequency of floods caused by heavy rain has increased significantly in recent years. A statistical model is developed that simulates peaks for each event type by type-specific peak–volume relationships. In a simulation study, we show how changes in frequency of flood event type lead to changes in the quantiles of annual maximum series. 相似文献
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The peak in sediment transport in alluvial rivers generally lags behind the peak in discharge. It is thus not clear how the hysteresis in the sediment/discharge relationship may be impacted by damming, which can fundamentally alter the water and sediment regimes in the downstream reaches of the river. In this study, a total of 500 flood events in the Yichang–Chenglingji Reach (YCR) of the Middle Yangtze River immediately downstream of the Three Gorges Dam (TGD) are analysed to study the impacts of dam operations on the hysteresis of suspended sediment transport. Sediment rating curves, hysteresis patterns, as well as lag times, are investigated to determine the relationship between suspended sediment concentration (SSC) and flow discharge (Q) at different temporal scales, from inter-annual to individual flood events, for the pre- and post-TGD period from 1992 to 2002 and from 2003 to 2017, respectively. The results showed that the TGD operation decreased the frequency and magnitude of floods. The decrease in peak flow and increase in base flow weakened the flood contribution to the annual discharge by nearly 20%. However, the relative suspended sediment load contribution during flood events was much higher than the discharge contribution, and was little impacted by the dam. At seasonal and monthly scales, more than 80% of the suspended sediment was transported by ~65% of the water discharge in the summer and early autumn. The monthly SSC–Q relationship changed from a figure-eight to an anti-clockwise pattern after the construction of the TGD. For single flood events, the TGD operations significantly modified the downstream SSC–Q hysteresis patterns, increasing the frequency of anti-clockwise loops and the lag time between peak Q and peak SSC. These adjustments were mainly caused by differences in the propagation velocities of flood and sediment waves and the sediment ‘storage–mobilization–depletion’ process, whereas the influence of lateral diversions was small. © 2020 John Wiley & Sons, Ltd. 相似文献
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ABSTRACTTaking a representative catchment of the Yangtze River Delta region as the study area, this research evaluated sub-daily rainstorm variability and its potential effects on flood processes based on an integrated approach of the HEC-HMS model and design storm hyetographs. The results show that the intensities of rainfall on sub-daily scale are getting more extreme. The annual maximum 1-, 2- and 3-hour rainstorms followed significant upward trends with increases of 0.32, 0.43 and 0.44 mm per year, respectively, while the annual maximum 6-, 12- and 24-h events had non-significant rising trends. The detected significant trends in short-duration rainstorms were then used to redesign storm hyetographs to drive the HEC-HMS model, the results show that these changes in short-duration rainstorm characteristics would increase the flood peak discharge and flood volume. These findings indicate that regional flood control capabilities must be improved to manage the adverse impacts of rainfall variation under changing environments. 相似文献
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AbstractFlood frequency analysis can be made by using two types of flood peak series, i.e. the annual maximum (AM) and peaks-over-threshold (POT) series. This study presents a comparison of the results of both methods for data from the Litija 1 gauging station on the Sava River in Slovenia. Six commonly used distribution functions and three different parameter estimation techniques were considered in the AM analyses. The results showed a better performance for the method of L-moments (ML) when compared with the conventional moments and maximum likelihood estimation. The combination of the ML and the log-Pearson type 3 distribution gave the best results of all the considered AM cases. The POT method gave better results than the AM method. The binomial distribution did not offer any noticeable improvement over the Poisson distribution for modelling the annual number of exceedences above the threshold.
Editor D. KoutsoyiannisCitation Bezak, N., Brilly, M., and ?raj, M., 2014. Comparison between the peaks-over-threshold method and the annual maximum method for flood frequency analysis. Hydrological Sciences Journal, 59 (5), 959–977. 相似文献
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lCOMPOSITIONOFTHE"92.8"FLOODThreerainstormsoccurredfrom7ththrough13,,,August,1992inShaanxiProvince,diStributingfromnorthtosouthinsequence.Therainfallareacoveredtheregionsofintensivesoilerosion,'wheretheaveragerateoferosionis10,000-15',000ton/kmZ'year.Fig.IshowsisohyetsofrainfallintensityinthecatchmentoftheMiddleYellowRiVerdepictingthedistributionoftherainstormsfrom7thto13,,,August,1992(thehydrologicalBureauYRCC,1992).ThecenterofthefirstrainstormwaslocatedattheYikezhaomengPrefec… 相似文献