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潮州市大多数小型水库工程的集雨面积较小,洪水汇流时间短,用推理公式法程序和调洪演算程序的默认参数进行洪水过程线和调洪计算,会造成了洪水的洪峰肥大、洪量增多的假象,计算的结果使水位变高,消能设施要求变高。通过对程序的修改,使之能适合小型水库工程的设计。 相似文献
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《水力发电》2017,(12)
为分析汇流模型参数对洪水模拟效果的影响,提高模型参数率定的精确性,以山西省洪水预报系统中的纳什瞬时单位线汇流模型为研究对象,运用LH-OAT法对汇流模型参数进行定向改变,分析确定汇流模型参数在不同等级洪水、不同流域、不同目标函数中的敏感性,再基于变异系数法确定汇流模型参数综合敏感性系数。研究表明,纳什瞬时单位线汇流模型参数敏感性会随着洪水等级、流域特征、目标函数的不同而改变,且汇流模型参数的敏感性仅与目标函数洪峰误差PE、洪峰流量Q_(mi)有关,与其他的目标函数无关;C_1与C_2这2个汇流模型参数综合敏感性系数分别为0.58、0.42,均为敏感性参数,且C_2的敏感性大于C_1。 相似文献
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本文以防洪对象(赤峰)控制断面以上各水库坝址断面及无控制的区间洪水的组成为例,结合工程设计实践对洪水地区组成问题进行了重点分析。当设计断面发生设计频率的天然洪水时,通过拟定若干个以不同地区来水为主的组成方案,对每一组成方案计算上游工程所在断面和无工程控制的区间洪水的峰、量,以及各断面统一时间坐标的相应洪水过程线,对工程所在断面的洪水过程线经调洪计算得到下泄洪水过程线,再与区间洪水过程线组合(包括洪水演算),推求出设计断面的洪水过程线,从中选取可能发生又能满足设计要求的成果。 相似文献
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由于沅水水系五强溪水库流域面积大,流量控制站少,且洪水进入库区后,洪水波的传播方式变化较大,因此五强溪水库近坝区的洪水预报难度大。为提高五强溪库区洪水预报精度,采用XAJ-DCH模型(Xin′anjiang Digital Channel Model)对近坝区2016~2020年间13场洪水进行模拟,模型河道汇流分别采用了非线性水库法和马斯京根法,根据两种汇流方法的特点制定了两种不同的洪水预报方案。模拟结果表明:XAJ-DCH模型中两种河道演算方法均表现良好且简单实用,13场洪水的确定性系数基本位于0.7以上。非线性水库方法相比于马斯京根法考虑了河段断面情况以及水力特性,能够体现洪水运动的时空变化,且只需要率定河道糙率,其他参数如河道坡降、河宽以及河段长均可根据数字高程模型进行估计;马斯京根法需要率定4个河道参数,但马斯京根法模拟结果相比于非线性水库方法稍好。研究成果可为科学有效开展库区洪水预报、提高预报精度提供参考。 相似文献
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根据实测暴雨洪水资料,分析河边水文站暴雨空间分布特征,采用具有蓄满产流机制分析产流,采用推理过程线法分析汇流,并用实测暴雨洪水资料进行检验,通过曲线精度评定,结果表明:蓄满产流机制在半湿润山区是适用的,产汇流参数具有规律性,可供无资料地区移用或参考。 相似文献
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以淮河流域鲁台子上游大型水库群为例,比较水库修建前后下游断面洪水过程变化情况,分析水库群对洪水过程的总影响,提出逐库添加法划分各水库在洪水过程变化中的贡献,明确各水库的影响程度,采用分级聚类法对水库影响程度进行划分,甑别重要水库。结果显示淮河流域大型水库群显著削减了鲁台子断面洪水总量与洪峰流量,峰现时间也有所变化,各库贡献差异较大,其中梅山、响洪甸、宿鸭湖、南湾、鲇鱼山和佛子岭等6座水库对鲁台子断面洪水过程影响显著,是流域防洪调度的重点水库。 相似文献
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参数估计一直是河道水动力模型研究的难点之一,在传统的模型参数人为经验率定方法的基础上,提出了基于粒子群算法的模型参数优化校正方法,构建了参数校正优化模型,并将参数优化校正算法与河道水动力模型进行耦合,针对淮河干流和史灌河支流组成的研究区域,采用一维河道洪水演进模型,比较了糙率系数校正方法和传统经验估算法,校正方法得到的河段糙率系数值比人为经验估计值平均大0.01,淮河干流河段糙率略大于史灌河支流河段糙率,采用校正河段糙率系数得到的河道水位过程与实测值拟合更优,特别在主峰段洪水过程模拟精度显著改善,验证了本文所提出的参数优化校正算法的有效性,为复杂河道水动力模型参数的确定提供了一种有效方法。 相似文献
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利用RSA和Sobol’两种全局灵敏度分析方法,对新安江模型中的主要产汇流参数进行了灵敏度分析,分析中采用Latin超立方采样方法,设定了模型参数的合理取值范围。参数灵敏度分析结果表明,两种方法得到的结果比较一致,流域蓄水容量是最敏感的参数,其次为汇流参数。灵敏度分析为水文模型有效的参数率定提供了技术支持。 相似文献
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Flooding is a common natural disaster that causes enormous economic, social, and human losses. Of various flood routing methods, the dynamic wave model is one of the best approaches for the prediction of the characteristics of floods during their propagations in natural rivers because all of the terms of the momentum equation are considered in the model. However, no significant research has been conducted on how the model sensitivity affects the accuracy of the downstream hydrograph. In this study, a comprehensive analysis of the input parameters of the dynamic wave model was performed through field applications in natural rivers and routing experiments in artificial channels using the graphical multi-parametric sensitivity analysis (GMPSA). The results indicate that the effects of input parameter errors on the output results are more significant in special situations, such as lower values of Manning’s roughness coefficient and/or a steeper bed slope on the characteristics of a design hydrograph, larger values of the skewness factor and/or time to peak on the channel characteristics, larger values of Manning’s roughness coefficient and/or the bed slope on the space step, and lower values of Manning’s roughness coefficient and/or a steeper bed slope on the time step and weighting factor. 相似文献
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当流域汛期雨情报讯时段在特殊情况下出现变化时,流域汇流单位线必须事先进行时段转换后才能用于实际洪水预报。以实测水文原始数据为依据,根据示例流域在水文预报工作中的特殊需要,采用s曲线法对流域汇流单位线进行了实例转换和应用分析。分析成果符合相关行业规范精度标准,提出了分析成果的具体使用条件和应用范围,成果能够作为备选方法用于实际工作之中。 相似文献
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Flood inundation extent is highly dependent on intensive rainfall and topography of floodplain. This paper presents a study
to develop a flood inundation model for partially gauged upper Ganga catchment. For design flood computations, 100-year return
period of 1 h duration rainfall is adopted. This is obtained by intensity duration frequency (IDF) relationship based on Self
Recording Rain Gauge (SRRG) data of the study area. The SCS-CN method is used for rainfall excess computations. The Nakagami-m distribution has been used to compute Geomorphological Instantaneous Unit Hydrograph (GIUH) of different sub-catchments of
upper Ganga river system because of non-availability of observed hydrograph. Routing of the hydrograph has been done by the
Kinematic Wave (KW) approach. KW equations have been solved through Preissmann implicit method. The most sensitive KW parameters
(i.e. overland roughness and channel roughness) have been estimated for a stretch on river Bhagirathi, a tributary of river
Ganga. Nakagami-m distribution based GIUHs have been fed at the upper (i.e. input to the proposed model) as well as at downstream point (i.e.
output to the proposed model) of that river stretch. Consequently, KW parameters have been calibrated by comparing the computed
hydrograph with output hydrograph. Validation of estimated KW parameters has been carried out in the catchment of river Alaknanda
which is another significant tributary of river Ganga. Thereafter, adopted KW parameters have been applied to calculate the
design flood peak at the outlet of study area i.e. downstream of Haridwar city. Computations of overtopping water above the
natural levees downstream of Haridwar city have been carried out considering the levee as broad crested weir. Topographic
features of the floodplain have been obtained from freely available Shuttle Radar Topography Mission (SRTM) data. Finally,
extents of submerged areas in different flood hours corresponding to design rainfall have been developed by ArcGIS 9.2 software. 相似文献
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The objective of this study is to perform a sensitivity analysis of the SHETRAN model on the example of the torrential Lukovska River catchment in Serbia. The sensitivity analysis of the model was performed for the following parameters: the vertical saturated hydraulic conductivity of the subsurface soil, the horizontal saturated hydraulic conductivity in the saturated zone, the Strickler roughness coefficients for overland flow and for streams, the available water content in the soil and the erodibility coefficients due to rain and due to overland flow. It can be concluded that the water and sediment discharge are very sensitive to the values of the vertical saturated hydraulic conductivity of the subsurface soil in the range of 0.001 to 0.1 m/day; to the values of the horizontal saturated hydraulic conductivity in the saturated zone in the range of 0.01 to 5 m/day and to the values of the Strickler’s coefficients for overland flow and for rivers in the range of 0.1 to 100 m1/3s-1 and 15 to 40 m1/3s, respectively. The sediment concentrations in a flow and sediment discharge are very sensitive to the values of erodibility coefficient due to overland flow in the range of 0.5 to 1.5 mg/m2s and to the values of erodibility coefficient due to rain in the range between 0.1 and 40 J-1. The obtained results could be used to simplify the parameter calibration procedure and to facilitate estimation of parameters in ungauged mountainous basins of similar characteristics. 相似文献
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HUO Yongfeng 《水资源与水工程学报》2011,22(6):158-161
根据山西省气候特点,将全省分为4个暴雨分区。无资料地区多利用设计暴雨计算设计洪水,在推求设计洪水过程线时要用到设计暴雨的雨型。本文简述了设计暴雨日雨型及时雨型的分析方法,利用这些方法分别对每个暴雨分区进行分析,综合得出了各分区的设计日雨型和时雨型,并且还针对工程控制面积小、汇流历时不足1h的流域,构造出了派生雨型,使小流域利用设计暴雨推求设计洪水过程线所需的设计暴雨雨型更加完善。 相似文献