山地小流域降雨及输沙过程的计算模型及其数值模拟

本文依据山地小流域产流及汇流特征，采用数理分析方法，探讨了其降雨强度，出口流量及输沙率随时间变化过程的数学表达关系，建立了从降雨至径流输沙的系统模型，经编程计算，模拟值与某小流域降雨和汇流资料吻合较好。     

吉林省中小流域经验模型的应用探讨

由于中小河流水文站点多数都属于无资料站,所以用传统的经验相关或者流域水文模型有一定难度。吉林省水文水资源局水情预报中心的工作者根据多年预报经验总结提出吉林省中小流域经验模型。该方法主要依据流域特征以及降雨和洪峰流量的关系,推算流域产流;再根据时段降雨按照产流过程叠加处理,概化流量过程,进行洪水预报。属于产汇流一体的流量过程计算模型。     

WEPP在黄土高原小流域径流调控中的应用研究

针对黄土高原小流域降雨径流调控优化难以采用数学模型的情况,依据小流域模型试验资料,对WEPP2006流域版应用于黄土高原地区小流域产流、产沙模拟计算的适用性进行了研究.结果表明:WEPP流域版计算的流量和产沙量与原型观测值的相关性较显著,流量预测好于产沙量预测,WEPP模型与实体模型的结合是可能的;但计算值都比实测值偏大,只能在一定程度上反映其径流、产沙、输沙规律.     

降雨径流预报方案的设计研究

为了对小流域的降雨径流预报方案进行研究,选取湖南省面积为22.1 km2的清水流域为研究对象,产流方案采用C语言编写的程序来实现。对产流方案所模拟的13场洪水进行分析,模拟结果均较好,合格率为83.3%;汇流方案根据降雨历时以及汇流时段的不同,有2条单位线可供选择,用于复核单位线的洪水都取得了较好的模拟结果。设计的降雨径流预报方案在清水流域是完全适用的。     

TOPMODEL模型在半湿润地区径流模拟分析中的应用及改进

为了使TOPMODEL模型结构更合理,并能够用于半湿润地区或半干旱地区的径流过程模拟,文章对TOPMODEL模型的蒸发产流模块以及汇流模块进行改进,在蒸发产流模块中添加植被冠层截留蒸散发模型和Holtan超渗产流模型,汇流模块中坡面汇流采用瞬时单位线模型,河道汇流采用马斯京根河道洪水演进模型。通过对半湿润地区流域内降雨径流过程的模拟验证,表明通过对TOPMODEL模型的改进,模型对半湿润地区的降雨径流过程模拟精度有很大的提高,拓展了TOPMODEL模型适用范围。     

TOPMODEL模型改进及应用研究

为了使TOPMODEL模型结构更合理,并能够用于半湿润地区或半干旱地区的径流过程模拟,文章对TOPMODEL模型的蒸发产流模块以及汇流模块进行改进,在蒸发产流模块中添加植被冠层截留蒸散发模型和Holtan超渗产流模型,汇流模块中坡面汇流采用瞬时单位线模型,河道汇流采用马斯京根河道洪水演进模型。通过对半湿润地区流域内降雨径流过程的模拟验证,表明通过对TOPMODEL模型的改进,模型对半湿润地区的降雨径流过程模拟精度有很大的提高,拓展了TOPMODEL模型适用范围。     

多因素降雨产流量预报模型的探讨

在建立地质条件复杂流域的产汇流模型时,将不同的地质条件作为模型的产流参数纳入模型当中,建立流域降雨产流模型的线性方程组,求解线性方程组即可求出模型产流参数.     

沟谷横断面类型对产流过程的影响

汇流区域地貌形态是影响降雨径流过程的重要因素之一.以陕西绥德市某小流域的两条支沟(横断面分别为U型与V型)为研究对象,结合实测数据分析与基于物理概念的数值模拟方法,研究沟谷横断面类型对产流的影响.研究结果表明:在天然降雨条件下,V型支沟产流能力更强,土壤初始含水量、饱和渗透系数等因子影响洪峰值.雨型和初始地下水位对U、V型支沟产流都产生影响,U型的敏感程度更高.     

济宁市山丘区小流域山洪预报方案探讨

正一、引言按照水文气象资料条件,山东省济宁市山洪灾害防治区小流域可以分为三类:(1)有详细资料小流域;(2)无资料小流域;(3)有短系列降雨资料小流域。其中有详细历史雨洪资料小流域数量极少,多数是无资料和有较短系列降雨资料小流域,且短系列资料也多数是新建站点,积累的降雨场次资料相对较少。可应用于济宁市山丘区小流域山洪预报的方法,产流方案有降雨径流相关图、初损后损法,汇流方案有推理公式法、瞬时单位线法和经验公式法     

乌江渡水电站产汇流分析及应用

乌江渡水电站位于乌江中游,为了进一步了解乌江流域产流机制,加强应对突发意外情况时对流量变化的掌控,做好乌江渡水电站防洪预报工作,笔者从产流机制、产流方法、汇流机理和汇流方法对乌江流域进行深入的分析,将蓄满产流模型应用在乌江渡水库上,借用VB编程工具计算入库流量。举例计算了2018年一场降雨产生的径流,结果与实测数据对比,误差在可接受范围内,表明此编程模型适用于乌江渡水电站。     

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

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。     

水工定床模型相似度的研究

对水工定床模型相似性的分析可量化为模型相似度的比较。模型系统与原型系统之间的相似在于二者之间有若干个相似元。各相似元的相似值等于特征值比例系数和相应的特征权数的乘积。相似元的相似值总和为二者之间的相似度，即二者之间相似性的度量。水工定床模型系统与原型系统之间的相似性由十个相似元构成。根据这一理论，本文分析了模型的几何变形对流速、压强和相应场产生的变态效应，并以算例分析了变态率和几何比尺对水工定床模型相似度的影响。结果表明相似度量化评估有利于提高模型的相似性，水工定床模型宜多采用大比尺。     

Incorporating Influences of Shallow Groundwater Conditions in Curve Number-Based Runoff Estimation Methods

Runoff generation process in any watershed is mainly affected by precipitation, land use and land cover, existing soil moisture conditions and losses. Shallow groundwater table conditions that occur in many regions are known to affect the soil moisture retention capacity, infiltration and ultimately the runoff. A methodology that links soil moisture capacity to the shallow groundwater table or High-Water Table (HWT) using a nonlinear functional relationship within a curve number (CN)-based runoff estimation method, is proposed and investigated using single and continuous event simulation models in this study. The relationship is used to obtain an adjusted CN that incorporates the effect of change in soil moisture conditions due to HWT. The CN defined for average conditions is replaced by this adjusted CN and is used for runoff estimation. A single event model that uses Soil Conservation Service (SCS) CN approach is used for evaluation of variations in runoff depths and peak discharges based on different HWT conditions. A real-life case study from central Florida region in the USA was adopted for application and evaluation of the proposed methodology. Results from the case study application of the models indicate that HWT conditions significantly influence the magnitudes of peak discharge by as much as 43% and runoff depth by 48% as the water table height reaches the land surface. The magnitudes of increases in peak discharges are specific to case study region and are dependent on the functional form of the relationship linking HWT and soil storage capacity. Also, for specific values of HWT, an equivalency between HWT-based CN and wet antecedent moisture condition (AMC)-based CN can be established.     

A Fast Semi Distributed Rainfall Runoff Model for Engineering Applications in Arid and Semi-Arid Regions

A new GIS based rainfall runoff model is developed for engineering applications, achieving a highly automated watershed analysis process starting from watershed delineation and up to the runoff hydrograph calculation. The model can be classified as a semi-distributed time area model that adopts an improved grid based approach for calculation of watershed response. The model deals with each grid cell in the digital elevation model as an independent hydrologic unit. Travel time through each grid cell is estimated using Manning’s formula and a stream power formula that relates the hydraulic radius at the cell to the characteristics of its upstream watershed area and excess rainfall depth. The watershed response at its outlet is estimated by routing the response of each grid cell using a flow path response function that is defined for that cell. The routed responses of all watershed cells are then convoluted to produce the outflow hydrograph. Model advantages include accuracy improvements due to the incorporation of grid-based routing calculations (both translation and attenuation), fully automated model structure, and fast ability to model many watersheds simultaneously. The combination of these advantages constitutes the novelty of the model that makes it very suitable for engineering design as well as for real-time applications. The model was tested using the data of the experimental watershed, Walnut Gulch, Arizona, USA, gauged by 88 rainfall stations and several discharge recording flumes. The results show that the model can accurately predict the runoff hydrograph where suitable input is available.     

Generation of Runoff Components from Exponential Expressions of Serial Reservoirs

Taiwan frequently experiences heavy rainfall events during the summer. The rainfall–runoff regeneration is an important job in specific areas where excessive rainfall causes serious flooding. The primary goal of this study is to generate and understand runoff components of the watershed outlet by using a conceptual model of three linear cascade reservoirs. The conceptual model is needless to determine direct runoff and excess rainfall in advance. Every linear cascade reservoir has an independent response function with an exponential expression. The outflows of the linear reservoirs represent streamflow components of a watershed outlet during rainfall–runoff processes, in which surface runoff is considered as quick runoff, whereas subsurface and groundwater runoffs are slow runoffs. In the simulation process, mean rainfall as model inputs were estimated using the block Kriging method. Available recordings of 68 rainfall–runoff events during 1966–2002 were used as the study sample. Fifty-four events were calibrated to determine the best hydrograph parameters and were used to compare simulation precision resulting from the model with those based on the Nash with NLP. The efficacy of the proposed model was verified using the remaining 14 observed rainfall–runoff data from an actual basin. The seven averaged parameters, which were applied for verification, show that the IUH shape of quick flow is more sharp-pointed with the peak shifted forward than that of slow flow. In rainfall–runoff processes, peak discharge of quick runoff is far larger than that of slow runoff, the time it takes for the peak discharge for a quick flow is earlier than that for a slow runoff, and the base time of a slow flow is longer than that of a quick flow. Furthermore, this study also found: (1) the base time of a slow runoff hydrograph is the same as that of a total runoff hydrograph; (2) the base time of a quick runoff hydrograph is contrariwise to the value of the soil antecedent moisture; (3) an amount of quick runoff is directly proportional to that of total runoff. These analytical results reveal that the model used in this study is suitable to evaluate hydrological conditions in this and other watersheds and can be further applied to watershed management in Taiwan.     

三峡库区小流域降雨入渗和产流产沙特征试验研究

三峡库区暴雨集中,历时短,强度大,是造成土壤侵蚀的重要因素。为开展对三峡库区小流域降雨入渗和产流产沙特征研究,通过建立三峡库区小流域微缩模型,分别实施降雨强度为60,90,120 mm/h的3场人工模拟降雨,对小流域模型降雨入渗规律和径流侵蚀过程进行了分析。研究结果表明:径流量均随降雨强度的增加而增加,而降雨强度增加入渗的作用仅在一定范围内是有效的;随着降雨的进行,产流强度和入渗率都趋于稳定状态,入渗率服从对数函数规律,产流强度呈幂函数变化;3场降雨中累计产沙量和累计径流量的关系均满足幂函数形式,含沙量和侵蚀量之间呈较好的线性关系。该研究成果可为这一区域的水土流失防治提供重要的科学依据。     

Runoff and Sediment Yield Modelling for a Treated Hilly Watershed in Eastern Himalaya Using the Water Erosion Prediction Project Model

The Water Erosion Prediction Project (WEPP) watershed model was calibrated and validated for a hilly watershed treated with graded bunding and water-harvesting tank in high rainfall condition of eastern Himalayan range in India. The performance of the model for the treated watershed was unacceptable with percent deviation of −45.81 and −38.35 respectively for runoff and sediment yield simulations when calibrated parameter values for the nearby untreated watershed were used. This was possibly due to differences in soil properties and average land slope. When soil parameters were calibrated for the treated watershed, the model performance improved remarkably. During calibration, the model simulated surface runoff and sediment yield with percent deviations equal to +6.24 and +9.02, and Nash–Sutcliffe simulation coefficients equal to 0.85 and 0.81, respectively. During validation period, the model simulated runoff and sediment yield with percent deviations equal to +8.56 and +9.36, and Nash–Sutcliffe simulation coefficients equal to 0.81 and 0.80, respectively. The model tended to slightly under-predict runoff and sediment yield of higher magnitudes. The model performance was quite sensitive to soil parameters namely, rill erodibility, interrill erodibility, hydraulic conductivity, critical shear stress and Manning’s roughness coefficient with varying levels. The WEPP model picked up the hydrology associated with bund and water-harvesting tank, and simulated runoff and sediment yield well with overall deviations within ±10% and Nash–Sutcliffe simulation coefficients >0.80. Simulation results indicate that in high slope and high rainfall conditions of eastern Himalayan region of India where vegetative measures are not adequate to restrict soil loss within the permissible limit, the WEPP model can be applied to formulate structure-based management strategies to control soil loss and to develop water resources.     

黄土丘陵沟壑区坡面水保措施及植被对流域尺度水沙关系的影响

根据黄土高原高含沙水流的特点,认为次暴雨的产沙模数和径流深可用线性正比关系式来表示,关系式中比例系数表示流域单位径流深的输沙能力、次暴雨过程中流量超过临界值后的稳定含沙量以及流域历次洪水的平均含沙量。在此模型基础上,以黄土丘陵沟壑区的王家沟的两个毗邻地貌相似的两条沟为研究区,其中一条沟为经治理而另一条则未治理。探讨各种坡面水土保持措施及植被对流域水沙关系的影响。结果表明,治理流域和非治理流域具有相同的水沙关系,被治理沟的植被等坡面措施在流域尺度上仅通过减水来减沙。这主要是因为植被等坡面措施不能显著改变沟道的输沙能力,且由于植被不能很好地控制沟谷侵蚀和重力侵蚀,使得水流进入沟道后又会获取充足的泥沙补充,达到和治理前相同的径流输沙能力。因此可以认为,在仅有植被和其它坡面治理措施的情况下,治理流域的减沙率可用减水率来估计。本文的实际计算表明,在多年平均尺度、年际尺度和次暴雨尺度这一方法都有较好的精度。     

标准小区和大型坡面径流场径流泥沙监测方法分析

通过对子午岭林区地未开垦及开垦后分布设的标准小区与大型坡面径流场所测定的径流，泥沙资料进行对比分析，提出在非林地的坡面上有标准小区观测资料建立的坡面土壤流失方程有局限性；在林地上，无论是标准小区，还是大型坡面径流场所测定的径流，泥沙量，均可作为有林小流域径流量和混沙量的参考值。另根据对大型坡面径流场，标准小区和小流域把口站所测定的径流量，泥沙量资料进行分析，认为利用标准小区所测定的非林地泥沙量可以     

Deterministic Insight into ANN Model Performance for Storm Runoff Simulation

The artificial neural network (ANN) theory has been widely applied to practical applications in hydrology. Since watershed rainfall–runoff processes are nonlinear and exhibit spatial and temporal variability, the ANN model, which considers watershed nonlinear characteristics, can usually but not always obtain satisfactory simulation results. The training of an ANN network is based completely on the reliability of the available hydrologic records. The objective of this study was to provide deterministic insight into the limitations of storm runoff simulation when using ANN. Hydrologic records of 42 storm events from two watersheds in Taiwan were adopted for analysis. A deterministic runoff model was used to classify the hydrologic records into “usual” and “unusual” storm events. The analytical results show that the ANN model could provide good simulation results for “usual” storm events; however, its performance was poor when it was applied to “unusual” storm events because no consistent hydrologic characteristics could be extracted from the storm event records using ANN. The success of the ANN model in usual storm discharge simulations may be mainly due to the input vectors including the previous observed discharge. Moreover, the number of past periods of rainfall that were set as the input vectors of the ANN model was found to be highly correlated with the watershed time of concentration. It can be used to efficiently determine the ANN network structure instead of using iterative network training.