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悬移质瞬时输沙单位线的探讨 总被引:3,自引:2,他引:1
本文试用纳希瞬时单位线法推求悬移质瞬时输沙单位线.通过对陕北黄土丘陵沟壑区岔巴沟支流刘家沟流域暴雨、洪水、泥沙资料的分析,得到了产沙量W_s与地面径流量W的相关方程及瞬时输沙单位线滞时m_(s1)与平均产沙强度的I_(scP)相关方程.经验证,用本方法在已知净雨过程时,便可推出流域的悬移质输沙过程线. 相似文献
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利用陕南长江水系丹江荆紫关等6个流域降雨、径流和输沙的实测资料,用多种函数形式模拟其相互关系,选择出最优的模拟函数,提供了由降雨变化预测年径流和年输沙变化趋势的一种途径。井通过对汉江上游沮水河等15条支流8个影响输沙因子的分析优选,建立了以年雨量、植被盖度、治理程度及河网密度4个因子表示的河流输沙经验模型。 相似文献
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介绍了紧水滩流域水文概况、报汛站网的布置及产汇流特点与机制.通过对流域历史洪水资料的统计和分析,寻求降雨径流各因子的成因关系.建立了一种能适用于本流域降雨径流预报的方法(五轴相关法与单位线演算法).在应用中取得较好效果。 相似文献
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逆高斯分布地貌瞬时单位线 总被引:7,自引:0,他引:7
本文假设水质点在河道状态传播时间的概率密度函数服从逆高斯分布,并根据地貌瞬时单位线理论建立了逆高斯分布地貌瞬时单位线模型。推导了三级流域的瞬时单位线,并对其性质作了分析。 相似文献
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瞬时单位线法推求雨水管网入流流量过程线的研究 总被引:8,自引:0,他引:8
本文根据北京百万庄实测降雨径流资料和瞬时单位线理论,推求出雨水管网雨水口流域瞬时单位线参数N和K.从而可以根据实测降雨资料或合成模式降雨资料和相应的扣损方法计算雨水口流域地表径流流量过程线,为真实地模拟城市暴雨径流过程提供了一种可行的方法. 相似文献
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基于空间地理信息系统的流域分布式水文泥沙模型为研究流域产流产沙及在河道中的汇流、输移过程提供了,科学有效的手段.针对岷江上游镇江关流域土壤易受降雨侵蚀的问题,采用水沙耦合的流域分布式水文综合模型,对该流域1990年后典型年的径流及泥沙侵蚀输移过程进了数值模拟,并结合镇江关水文站的实测资料对模型进行了验证,计算成果令人满意.分析表明,近年来岷江上游地区的年径流和输沙量均呈现出下降的趋势,且后者下降速率更快,说明泥沙侵蚀输移与径流相比对流域环境变化的反应更为敏感,今后水土保持工作应注重坡面治理. 相似文献
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基于径流侵蚀功率的流域次暴雨输沙模型研究——以岔巴沟流域为例 总被引:4,自引:0,他引:4
流域次暴雨侵蚀产沙模型研究是国内外土壤侵蚀研究的重点领域之一。提出了基于径流深和洪峰流量模数两个流域次暴雨洪水特征参数的径流侵蚀功率的概念;利用岔巴沟曹坪水文站1959至1990年间历年实测的次暴雨洪水径流泥沙资料,系统研究了该流域次暴雨径流侵蚀功率与流域输沙模数之间的相关关系,建立和验证了基于径流侵蚀功率的岔巴沟流域次暴雨输沙模型。结果表明,岔巴沟流域次暴雨径流侵蚀功率与流域输沙模数之间具有极显著的幂函数相关关系;模型验证期的次暴雨输沙模数模拟值与实测值之间具有较好的一致性。 相似文献
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Assessing Downstream Impacts of Detention Basins in Urbanized River Basins Using a Distributed Hydrological Model 总被引:1,自引:1,他引:0
Giovanni Ravazzani Paride Gianoli Stefania Meucci Marco Mancini 《Water Resources Management》2014,28(4):1033-1044
It is widely recognized that urban development alters infiltration capacity and enhances its spatial variability, but also constrains watercourses into narrow channels making them unable to contain the runoff that is generated by relatively small, but intense, rainfall events. Network of detention basins are designed to reduce the flood peak by temporarily storing the excess storm water and then releasing the water volume at allowable rates over an extended period. This paper shows the use of a distributed hydrological model for the assessment of effectiveness of a network of detention facilities in a heavily urbanized river basin. The distributed hydrological model FEST was used to assess design hydrograph and, in parallel to design the seven detention basins optimized for the specific purpose of maintaining the flow rate within the range of the maximum allowable discharge. This permitted to estimate the design hydrograph considering both the spatial variability of soil infiltration capacity and routing characteristics induced by each detention basins along the main river. Results indicate that on-stream detention ponds can increase duration of the critical event and runoff volume of design flood with possible negative implications on downstream facilities. 相似文献
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小流域产流产沙动力学模型 总被引:16,自引:1,他引:15
按自然水系划分单元,每一单元又被概化为“一本打开的书”概化后的单元又区分为几个微地貌区。各单元水沙过程演算至流域出口迭加得流域产流产沙过程。此法一方面解决了降雨,侵蚀和下垫面的不均匀性,另一方面又解决了水沙的演算问题。坡面和沟道水流用运动波方程描述并用四点隐式差分格式求其数值解。根据水流作功和能量平衡原理推导出各微地貌区上的土侵蚀量计算公式,建立起具有物理过程基础的小流域产流产沙模型。 相似文献
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主要研究对河流的水电能资源进行梯级开发所带来的生态影响。从水文、水环境、生物、水土流失等方面进行分析,并应用灰色GM(1,1)模型,对第二松花江流域的三个断面、八项指标进行预测和评价。结果表明:流域梯级电站的建设,有利于流域内鱼类资源数量的增加、显著减少输沙量,但会不同程度地减少河流年平均流量、对开发和保护鱼类种类有负面影响。因此,河流水电的梯级开发需要谨慎规划,合理调度,各级大坝的选址、坝高、运行期间的蓄水量等都会影响到整个流域的生态安全。 相似文献
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This paper describes a flood routing method applied in an ungauged basin, utilizing the Muskingum model with variable parameters of wave travel time K and weight coefficient of discharge x based on the physical characteristics of the river reach and flood, including the reach slope, length, width, and flood discharge. Three formulas for estimating parameters of wide rectangular, triangular, and parabolic cross sections are proposed. The influence of the flood on channel flow routing parameters is taken into account. The HEC-HMS hydrological model and the geospatial hydrologic analysis module HEC-GeoHMS were used to extract channel or watershed characteristics and to divide sub-basins. In addition, the initial and constant-rate method, user synthetic unit hydrograph method, and exponential recession method were used to estimate runoff volumes, the direct runoff hydrograph, and the baseflow hydrograph, respectively. The Muskingum model with variable parameters was then applied in the Louzigou Basin in Henan Province of China,and of the results, the percentages of flood events with a relative error of peak discharge less than 20% and runoff volume less than 10% are both 100%. They also show that the percentages of flood events with coefficients of determination greater than 0.8 are 83.33%, 91.67%, and 87.5%,respectively, for rectangular, triangular, and parabolic cross sections in 24 flood events. Therefore,this method is applicable to ungauged basins. 相似文献
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Application of a simulated annealing optimization to a physically based erosion model 总被引:1,自引:0,他引:1
A major risk concerning the calibration of physically based erosion models has been partly attributable to the lack of robust optimization tools. This paper presents the essential concepts and application to optimize the erosion parameters of an erosion model using data collected in an experimental basin, with a global optimization method known as simulated annealing (SA) which is suitable for solving optimization problems of large scales. The physically based erosion model that was chosen to be optimized here is the Watershed Erosion Simulation Program (WESP), which was developed for small basins to generate the hydrograph and the respective sedigraph. The field data were collected in an experimental basin located in a semiarid region of Brazil. On the basis of these results, the following erosion parameters were optimized: the soil moisture-tension parameter (N(s)) that depends also on the initial moisture content, the channel erosion parameter (a), the soil detachability factor (K(R)), and the sediment entrainment parameter by rainfall impact (K(I)), whose values could serve as initial estimates for semiarid regions within northeastern Brazil. 相似文献
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在全球变化等多种因素的影响下,许多流域的泥沙问题严重,泥沙管理的重要性日益突出。通过对联合国教科文组织国际泥沙计划所开展的案例研究进行综述,认识到自然地理特征、社会经济条件、水利工程建设对流域产沙、输沙和水资源利用有重要影响。土壤侵蚀加速、水库淤积、下游输沙量减少和生态平衡破坏是目前全球各大流域面临的主要问题。综合各项案例,研究泥沙管理技术,提出流域综合泥沙管理的策略,包括水库淤积管理、推移质泥沙管理、土地管理和水土保持等技术手段,以及法律、行政和组织措施。 相似文献