共查询到19条相似文献，搜索用时 265 毫秒
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张家口市地处河北省西北部,境内降水比较集中,沟谷众多,洪水暴涨暴落。在中、小型水利工程、公路工程、河道整治工程之中,小流域不同频率的洪峰流量决定了工程项目的选址、规模、预算和效益,具有重要的意义。针对张家口市小流域洪水实际情况,以安固里河为例,分别采用地区经验公式法、推理公式法、水文资料频率计算法三种方法对洪峰流量进行了计算。通过对三种洪峰流量计算方法结果进行分析,推荐以水文资料频率计算法作为张家口市小流域设计洪水首选方法。在没有实测水文资料情况下如果工程比较重要、资金比较充裕可以选取安全系数较高的地区经验公式计算结果;如果工程重要程度一般、资金有限制可以选取安全系数较高推理公式计算结果。 相似文献
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为分析推理公式法在土耳其小流域设计洪水计算中的适应性,首先分析了土耳其常用洪水计算方法 DSI Synthetic Method在设计降雨、产流规律、汇流模型的水文特点,并将DSI Synthetic Method与我国常用的两类推理公式法进行比较,探讨土耳其降雨径流关系与推理公式法汇流模型相结合进行小流域洪水计算的方法,最后通过土耳其工程实例将该方法与DSI Synthetic Method设计洪水计算成果进行比较。研究结果表明,改进的推理公式法能够将土耳其的设计降雨、产流规律和推理公式法汇流模型相结合,设计洪水计算成果能够符合当地实际情况。 相似文献
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随着城乡经济建设飞速发展,洪水出现的频率及其造成的损失也不断的增加。快速、准确、科学地分析洪水特性,对于发挥防洪工程效益,兴利除害具有十分重要的意义,本文以喀拉果勒洪沟流域为研究对象,针对拟建引水渠首断面进行洪水计算,通过对洪水成因类型、历史重现期分别进行分析,采用调查洪水校正法、推理公式法和洪峰流量模比系数综合频率法三种常用方法进行渠道设计洪水推求,并对计算成果合理性进行对比分析,认为洪峰流量模比系数综合频率法最为合适,最终选择最大洪峰流量设计成果的参数Kp。研究成果可为工程建设提供安全经济可靠的设计方案。 相似文献
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以滇东典型小流域——罗平县板桥小流域为例,进行滇东山区小流域山洪风险评估的实证研究,提出滇东小流域山洪灾害风险评估方法,得到结论如下:(1)首先采用曼宁公式推求设计洪水位;再次基于DEM利用地理信息技术进行洪水的淹没范围分析;最后根据淹没范围,统计不同危险区内的人口和建筑等的分布情况,从而进行洪灾损失评估。(2)根据对小流域暴雨洪水的计算,采用水文比拟法推算出板桥小流域范围内10个重要河段控制断面的设计洪峰流量,然后再采用曼宁公式进行洪峰水位推求,其中有8个现状防洪能力不能抵抗10a一遇的洪水,现状防洪能力较低。因此板桥小流域范围内重点沿河村落的防洪能力亟待提高。 相似文献
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西北干旱山区受地形及观测条件限制多为无实测资料的小流域，常见流域洪水计算方法计算精度难以适用于山区小流域。本文通过采用地方经验公式方法和原铁一院推理公式实例计算分析，得出地方经验公式适用于10 km2以下的极小流域、原铁一院推理公式适用于10～100 km2的较小流域地区的结论，为无实测资料的干旱山区小流域选择设计洪水计算方法提供科学依据。 相似文献
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Geomorphic effects observed in the Barranco (creek) de Arás basin are used to characterize the flood. Sediment features allow to qualify the flood as essentially a water flow. Using the critical section method, the peak flood discharge is estimated to be between 400 and 600 m3 s−1. Similar results were obtained using a paleohydraulic formula based on the size of the largest mobilized clasts. Using the rational method with available rainfall data, the discharge for a recurrence interval of 500 years is estimated to be between 150 and 200 m3 s−1. These results agree with predictions obtained using curves of peak discharge versus basin area based on regional data. Several trenches dug on the fan showed that the size of boulders mobilized by the event is larger that those left by previous floods at the same place. When the estimated peak flood discharge is related to the basin area, values between 20 and 30 m3 s−1 km−2 are obtained, demonstrating that the Barranco de Arás flood was most unusual. 相似文献
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Several small reservoirs and a large number of check dams had been constructed in the Wangkuai reservoir watershed after 1970s, and flood time series lacked stationarity, which affected the original design flood hydrographs for the Wangkuai reservoir. Since the location, storage capacity and drainage area of the large number of check dams were unknown, we present a method to estimate their total storage capacities (TSC) and total drainage areas (TDA) by using the recorded rainstorm and flood data. On the basis of TSC and TDA, the flood events which occurred in an undisturbed period were reconstructed under current conditions to obtain a stationary flood series. A frequency analysis was subsequently performed to assess the design flood peak and volume for both small and medium design floods with a 10–200 year return period. For large and catastrophic floods, it was assumed that the upstream check dams and small reservoirs would be destroyed, and water stored in these hydraulic structures were re-routed to the Wangkuai reservoir by unit hydrograph. The modified flood peak and volume decreased for floods with a 10–200 year return period when compared to the current design flood. But for large design floods with a return period exceeding 500 years, peak discharge increased. This study provides a new method for design flood calculation or modification of the original design flood in watersheds with a large number of check dams. 相似文献
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The currently adopted rainfall-based design flood estimation method in Australia, known as design event approach (DEA), has a flaw that is widely criticized by the hydrologists. The DEA is based on the assumption that a rainfall depth of a certain frequency can be transformed to a flood peak of the same frequency by adopting the ‘representative values’ of other model input variables, such as temporal patterns and losses. To overcome the limitation associated with the DEA, this paper develops stochastic model inputs to apply Monte Carlo simulation technique (MCST) for design flood estimation. This uses data from 86 pluviograph stations and six catchments from eastern New South Wales (NSW), Australia, to regionalize the distributions of various input variables (e.g., rainfall duration, inter-event duration, intensity and temporal patterns and loss and routing characteristics) to simulate thousands of flood hydrographs using a nonlinear runoff routing model. The regionalized stochastic inputs are then applied with the MCST to two catchments in eastern NSW. The results indicate that the developed MCST provide more accurate flood quantile estimates than the DEA for the two test catchments. The particular advantage of the new MCST and stochastic design input variables is that it reduces the subjectivity in the selection of model input values in flood modeling. The developed MCST can be adapted to other parts of Australia and other countries. 相似文献
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为实现中小流域降雨径流过程精细化模拟, 合理估算水文模型参数的空间分布具有重要意义。基于新版全球数字土壤制图系统(SoilGrids)构建栅格新安江模型(GXM)参数化方案, 对陕西省陈河流域2003—2012年16场洪水进行模拟, 与新安江模型计算结果进行对比, 开展基于洪水过程划分的自由水蓄水容量敏感性及空间分布特征量化分析。结果表明: GXM模拟的峰现时间误差水平降低约0.31 h, 洪峰和洪量模拟精度较高, 模型能够对土壤水饱和度等水文要素的动态空间分布进行较合理的模拟; 自由水蓄水容量参数对洪峰和涨洪过程的确定性系数以及涨洪段的洪量相对误差影响较大, 对退水过程影响小; 自由水蓄水容量在陈河流域河谷和山脊附近较大, 坡段中部较小。 相似文献
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Flash flood disaster is a prominent issue threatening public safety and social development throughout the world, especially in mountainous regions. Rainfall threshold is a widely accepted alternative to hydrological forecasting for flash flood warning due to the short response time and limited observations of flash flood events. However, determination of rainfall threshold is still very complicated due to multiple impact factors, particular for antecedent soil moisture and rainfall patterns. In this study, hydrological simulation approach (i.e., China Flash Flood-Hydrological Modeling System: CNFF-HMS) was adopted to capture the flash flood processes. Multiple scenarios were further designed with consideration of antecedent soil moisture and rainfall temporal patterns to determine the possible assemble of rainfall thresholds by driving the CNFF-HMS. Moreover, their effects on rainfall thresholds were investigated. Three mountainous catchments (Zhong, Balisi and Yu villages) in southern China were selected for case study. Results showed that the model performance of CNFF-HMS was very satisfactory for flash flood simulations in all these catchments, especially for multimodal flood events. Specifically, the relative errors of runoff and peak flow were within?±?20%, the error of time to peak flow was within?±?2 h and the Nash–Sutcliffe efficiency was greater than 0.90 for over 90% of the flash flood events. The rainfall thresholds varied between 93 and 334 mm at Zhong village, between 77 and 246 mm at Balisi village and between 111 and 420 mm at Yu village. Both antecedent soil moistures and rainfall temporal pattern significantly affected the variations of rainfall threshold. Rainfall threshold decreased by 8–38 and 0–42% as soil saturation increased from 0.20 to 0.50 and from 0.20 to 0.80, respectively. The effect of rainfall threshold was the minimum for the decreasing hyetograph (advanced pattern) and the maximum for the increasing hyetograph (delayed pattern), while it was similar for the design hyetograph and triangular hyetograph (intermediate patterns). Moreover, rainfall thresholds with short time spans were more suitable for early flood warning, especially in small rural catchments with humid climatic characteristics. This study was expected to provide insights into flash flood disaster forecasting and early warning in mountainous regions, and scientific references for the implementation of flash flood disaster prevention in China. 相似文献
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Response of bankfull discharge of the Inner Mongolia Yellow River to flow and sediment factors 总被引：1，自引：0，他引：1
Bankfull discharge is a comprehensive factor reflecting the channel-forming capability of water flow and the flood and sediment transport capacity of a river channel. It is based on the interaction of the flow, sediment, and river channel, of which flow and sediment conditions play crucial roles. Using data recorded since the 1950s, this paper analyses statistically, the characteristics and variations of bankfull discharge at two stations on the Inner Mongolian reaches of the upper Yellow River. Results indicate that flood season variations in bankfull discharge are nonlinear and are governed by flood peak discharge, mean discharge, and the mean incoming sediment coefficients. Variation in bankfull discharge is related not only to the flow and sediment conditions of the current year but also to those of previous years. The 10-year moving average of flow and sediment conditions can be representative of present and previous years. By considering flood season peak discharge and incoming sediment coefficients as independent impact factors, a formula is derived to determine bankfull discharge. The results can be used to predict the bankfull discharge of the Yellow River channel in Inner Mongolia under specific flow and sediment conditions and provide reference for the purpose of further study related to restoring and maintaining the basic functions of the river channel regarding flood discharge and sediments. 相似文献
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利用Copula函数建立各分区洪水的联合分布,基于联合概率密度最大原则,推导得到最可能地区组成法的计算通式,并用来推求梯级水库下游断面的设计洪水。选择清江流域水布垭-隔河岩-高坝洲梯级水库为例,开展了验证和方法比较研究。结果表明:最可能地区组成法计算得到的设计洪水值位于同频率地区组成法多方案计算结果的区间之内;受清江梯级水库调洪的影响,宜都断面设计洪水的削峰率十分显著,最可能地区组成法推求100年一遇设计洪水的削峰率达到30.2%。该法具有较强的统计基础,组成方案唯一,结果合理可行,为复杂梯级水库设计洪水的计算提供了一种新途径。 相似文献
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为了计算瞬时溃坝最大流量,基于堰流与波流量相等原理,建立了瞬时溃坝最大流量与堰流关系,理论推导得到同一公式可以计算大坝全溃、横向局部溃坝、垂向局部溃坝及横垂向局部溃坝的瞬时最大流量的新通式,给出了该通式的基本和上限、下限及一般等通式。研究发现:瞬时溃坝流量与溃口堰坎类型有关,可以把瞬时溃坝最大流量、逐渐溃坝洪水或漫坝洪水的计算公式和相应系数统一到不同堰坎类型的堰流量计算中;而这些新通式相应系数的取值是被实验确认和经典著作肯定的,保证了系数取值的可靠和准确。这些新通式容易理解、形式简单、计算简便,参数取值可靠,把溃坝洪水计算的复杂问题转变为处理经典水力学的简单堰流计算。同时通过对比分析,充分论证了一般通式的合理性,并用国内外溃坝实例验证了计算方法和成果较科学、可靠、合理。 相似文献
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Statistical approach to the analysis of the relationship between the frequency of flood events and land cover (LC) changes
in small catchments of Slovakia is presented in this paper. The data for identification of LC changes were taken from the
1990 and 2006 CORINE LC (CLC) data layers. They were derived by computer-aided visual interpretation of satellite images under
the CLC Projects. The data about frequency of flood events in small catchments are from the period 1996–2006. Two hypotheses
were formulated: (1) the greater the area of LC changes, the more frequent flood events; (2) in catchments where LC changes
accelerating formation of direct runoff (e.g. urbanization, deforestation, farming) dominates, flood events are more frequent
than in catchments where the prevailing LC changes (e.g. afforestation) reduce formation of direct runoff. Validity of hypotheses
was tested in the framework of flood potential of catchments by two-factor ANOVA method. The obtained results indicate that
(1) flood event frequency increases with the increasing total area of LC changes in a catchment. This tendency clearly manifests
itself in catchments with very high flood potential. It is somewhat less distinct in catchments with moderate and high flood
potentials. (2) There were no differences in flood event frequency between the group of catchments, where LC changes accelerating
the formation of the direct runoff prevailed and the group of catchments where LC changes decelerating the formation of direct
runoff were dominated. 相似文献