湖泊不同湖区CODMn降解的混合级数模型

基于湖泊有机物组成的复杂性,提出考虑流速效应的湖泊高锰酸盐指数混合级数降解模型.将高锰酸盐指数分为可降解部分和不可降解部分,把可降解部分的反应级数作为自由参数,避免了事先假定反应级数对模型拟合的限制.以太湖为研究对象,将太湖分为湖湾、湖岸和湖心区,分别进行室内静态和动态模拟实验,研究了不同水动力条件对降解系数的影响,建立降解系数与流速的关系式;考虑不同湖区的流速效应,构建了不同湖区的混合级数模型,模型更为符合有机污染物降解的实际情况,并具有更高的精度和更广的适用性.     

湖泊不同湖区CODMn降解的混合级数模型

摘要：基于湖泊有机物组成的复杂性，提出考虑流速效应的湖泊高锰酸盐指数混合级数降解模型。将高锰酸盐指数分为可降解部分和不可降解部分，把可降解部分的反应级数作为自由参数，避免了事先假定反应级数对模型拟合的限制。以太湖为研究对象，将太湖分为湖湾、湖岸和湖心区，分别进行室内静态和动态模拟实验，研究了不同水动力条件对降解系数的影响,建立降解系数与流速的关系式；考虑不同湖区的流速效应，构建了不同湖区的混合级数模型，模型更为符合有机污染物降解的实际情况，并具有更高的精度和更广的适用性。     

平滩流量滞后响应模型的改进

针对冲积河流平滩流量滞后响应模型中存在的不足,对模型进行了两方面的修正:一是对原模型的结构形式进行了修正,包括调整了初始年份平滩流量平衡值Qe0的影响权重,推导了不同年份采用不同参数β时的模型方程;二是对模型中参数的计算方法进行了修正,包括考虑洪峰流量的影响修正了平滩流量平衡值Qe的计算方法,考虑汛期流量的影响修正了参数β的计算方法。利用黄河下游花园口、高村、孙口、艾山和利津五个水文站的实测资料对改进的模型进行验证,结果表明,修正后的模型反映了平滩流量随水沙条件改变的调整规律,模型计算精度有较大提高。     

邓肯-张E-B模型参数对高面板坝应力变形的影响

邓肯 张E B模型在混凝土面板堆石坝中得到了较为广泛的应用。大量计算研究表明,许多时候模型参数变化对计算结果的影响比模型本身的影响还要大。结合具体工程的试验和计算研究成果,对模型参数按比例分别增减,用有限元法计算某一面板坝的应力、位移等。每个参数的增减变化都将引起应力、位移的相应变化,其中参数Kb,φ0对面板坝应力、位移的影响最显著。分析还表明,对参数m的取值应特别慎重。     

基于伯格模型的非饱和土蠕变模型构建

滑坡变形发展一般都要经历一定的时间过程,同时在降雨以及库水位变动下,滑坡土体常处于非饱和状态,因此构建考虑基质吸力的非饱和土蠕变模型具有非常重要的意义。以三峡库区某滑坡滑带土非饱和蠕变试验数据为基础,基于伯格模型和非饱和土力学原理及相关假设条件,构建了适合该滑坡滑带土的非饱和蠕变模型。接着,利用非线性回归算法对模型参数进行求解,并将该模型预测值与试验值进行对比,验证了该模型的合理性。最后,考虑模型参数与净围压之间的线性相关性,对模型进一步修正,并验证了修正后模型的有效性。构建的非饱和土蠕变模型能较好地反映该滑坡滑带土的非饱和蠕变特性,其对预测该滑坡的长期变形具有重要的意义。     

城市暴雨管理模型应用研究进展

回顾了城市暴雨管理模型SWMM的发展过程,着重分析了模型开发关注的重点问题:子流域划分尺度、模型参数的选取和设定、参数不确定性及灵敏度分析、参数的率定、模型结构的不确定性分析、模型开发与耦合等,对模型在水文过程模拟、水动力过程模拟、水质过程模拟3个方面的应用进行了评述,并对模型未来的优化应用和开发提出了建议和展望。     

SCS-CN模型的改进及其空间尺度效应

SCS-CN (Soil Conservation Service Curve Number)模型是广泛应用经验性水文模型,其模型参数的确定与空间尺度效应对径流模拟结果有着重要的影响。选取淮河上游为研究区,分析SCS-CN模型参数的敏感性并对模型进行改进,探讨了9种栅格尺度(100～2 000m)下径流模拟结果的空间尺度效应。研究结果表明:SCS-CN模型输入参数中,系数b的敏感性高于初损系数(λ),将参数b值作为模型需要修正的参数;随着空间尺度增加,下垫面各要素的尺度变化使得参数b呈指数递减趋势;模型模拟精度的最佳空间尺度范围是250～500m尺度。     

拱坝随机地震行波效应分析

将随机振动的虚拟激励法与拱坝地基动力相互作用FE-BE-IBE时域模型结合,发展了一个可以考虑随机地震动行波效应的拱坝随机动力响应计算模型,并用Monte-Carlo法对模型进行了验证.不同行波波速的计算结果表明,行波效应可以影响拱坝的动力响应,幅度在10%~20%,较小的行波波速在坝体边界产生应力集中现象,表明行波效应对拱坝动力响应具有显著影响.     

利用MIKEBASIN模型软件构建流域水资源配置模型

文章以松花江流域哈尔滨断面以上区域为样本区,论述利用MIKE BASIN模型软件如何搭建流域(区域)水资源配置模型。对模型目标参数选择、模型数据输入条件、模型参数率定、模型数据分析及采用等方面都进行简要论述,并对建模过程中出现的问题进行分析,提出了相应的建议,为今后对模型进行深入研究和模型如何利用能起到积极借鉴作用。     

考虑应力敏感的页岩气藏垂直裂缝井压力动态分析

压裂井由于能够提高单井产量而在页岩气藏开发过程中得到了广泛的应用。在实际生产过程中,页岩气藏往往存在明显的应力敏感作用。为此,该文应用椭圆渗流的概念,综合考虑了页岩气解吸、扩散和渗流特征,建立了考虑应力敏感作用的页岩气藏双重孔隙介质垂直裂缝井椭圆流动渗流数学模型。考虑到模型非线性程度较高,重新定义部分参数,将解吸作用考虑成基质综合压缩系数的增加,并通过Laplace变换、摄动变换以及Duhamel原理,结合Stehfest数值反演技术对模型进行了求解,绘制了压力动态典型曲线,分析了应力模数、裂缝导流能力、Langmuir压力、Langmuir体积、窜流系数等参数对压力动态曲线的影响,其研究结果可为页岩气藏压力动态的合理分析提供科学依据。     

堆石坝流变变形的反馈分析

本文中建议了一个比较简单实用的3参数模型，并通过4座已建坝的反馈分析确定了从软岩到砂卵石4种不同质地堆石料的流变参数，今后新建类似堆石坝时可以参考此值进行设计计算。     

Sensitivity Analysis of the GIUH based Clark Model for a Catchment

For estimation of runoff response of an ungauged catchment resulting from a rainfall event, geomorphologicalinstantaneous unit hydrograph (GIUH) approach is getting popularbecause of its direct application to an ungauged catchment. Itavoids adoption of tedious methods of regionalization of unithydrograph; wherein, the historical rainfall-runoff data of anumber of gauged catchments are required to be analyzed. In thisstudy, the GIUH derived from geomorphological characteristics ofa catchment has been related to the parameters of Clark IUH modelfor deriving its complete shape. The DSRO hydrographs estimatedby the GIUH based Clark model have been compared with the DSROhydrographs computed by the Clark IUH model option of the HEC-1package and the Nash IUH model by employing some of the commonlyused error functions. Sensitivity analysis of the GIUH basedClark model has been conducted with the objective to identify thegeomorphological and other model parameters which are moresensitive in estimation of peak of unit hydrographs computed bythe GIUH based Clark model. So that these parameters may beevaluated with more precision for accurate estimation of floodhydrographs for the ungauged catchments.     

Single Event Watershed Model for Simulating Runoff Hydrograph in Desert Regions

This study is aimed to use the available limited meteorologicaland hydrological data for two catchments located in the westernIraqi desert, to develop and apply a simple single event watershed model to simulate and predict the surface runoff hydrograph. The single event watershed model is based on the water balance equation. The inputs to the model are rainfall,evaporation, and soil properties data. The Resonbrock optimization technique is employed to determine the optimum parameters of the model. Also a simple and a modified versionof this model is suggested and tested for the study area. Theavailable rainfall and runoff data in these catchments have beenused in calibrating and testing the model. In model testing, theoptimized parameters for a particular storm are used to test themodel performance on other available storms and so on. Sensitivity analysis has been used to determine the most sensitive parameters.     

加里宁－米留柯夫型流域地貌汇流模型

本文根据概念性流域地貌汇流模型的一般理论，建立了加里宁－米留柯夫型流域地貌汇流模型、推导了三级、四级和五级流域的瞬时单位线，并分析了模型参数对瞬时单位线的影响．用内罚函数法估计模型参数．通过实例检验，模型拟合精度较高．     

Analytical and Experimental Investigation of Flow Distribution in Manifolds for Heat Exchangers

The prediction of flow distribution in flow manifolds is important for the design of heat exchangers. The pressure drop along the flow in the header is the most influential factor in flow distribution. Various continuous models available in literature have failed to satisfactorily predict the pressure distribution in the headers of the flow manifolds. In this article, a discrete model matching the real physical phenomena has been proposed, to predict the pressure distribution in headers. An experimental evaluation of relevant flow characteristic parameters has been carried out to support the discrete model calculations. The validity of the theoretical discrete model has been performed with experimental results, under specific conditions. Refined experimental probes, for pressure heads with ultrasonic measuring devices, have been used to obtain accurate results. The experimental results fully substantiate the soundness of the theoretical prediction. In addition, the advantage of the ability to accommodate local disturbances in the discrete model has been pointed out. The effect of some local disturbances may be substantial. As a result of the analysis presented in this article, improved designs of flow manifolds in heat exchangers can be realized, to assure operation safety under severe operating conditions.     

新安江模型参数变化对流域降雨径流过程的影响分析

水文模型可以模拟自然流域的降雨径流过程,在降雨径流过程模拟中,水文模型参数的选择往往会影响模型对流域径流过程的模拟效果.针对新安江模型,以陕西黑河金盆水库流域为研究流域,分析新安江模型参数变化对模拟流域降雨径流过程的影响,以确定新安江模型参数的敏感程度,从而服务于研究流域的汛期水文预报参数修正.模拟结果表明:在研究流域新安江模型参数中KKSS、KKG、WLM、WDM、kg、k为敏感参数,对模拟流域降雨径流过程的影响较大;参数WUM、IMP、B、c、SM、EX为不敏感参数,对模拟流域降雨径流过程影响较小.     

Evolving Effective Hydraulic Model for Municipal Water Systems

Constructing a robust hydraulic network model is vitally important, but a time-consuming task. Over last two decades, several approaches using optimization techniques have been developed for identifying model parameters. Although most of the methods can make the model agree with field observations, few are able to achieve a good level of accuracy in terms of determining the correct model parameters for a water distribution system. The previously developed methods appear to be lacking versatility for users to specify calibration tasks given real data for a real system. This paper proposes a comprehensive framework for evolving a hydraulic network model. Calibration tasks can be specified according to data availability and model application requirements. It allows an engineer to (1) flexibly choose any combination of the model parameters such as pipe roughness, junction demand and link (pipes, valves and pumps) operational status; (2) easily aggregate model parameters to reduce the problem dimension for expeditious calculation and (3) consistently specify boundary conditions and junction demand loadings that are corresponding to field data collection. A model calibration is then defined as an implicit nonlinear optimization problem, which is solved by employing a competent evolutionary algorithm. With this methodology, a modeler can be fully assisted to carry out not only a single parameter optimization run, but also a variety of calibration tasks in a progressive manner according to practical system conditions, thus it is possible to achieve a good model calibration with high level of confidence. The method has been applied to the model of a municipal water system to demonstrate the efficacy and robustness of the evolutionary modeling practices.     

闽江流域洪水预报模型比较研究

应用新安江模型与垂向混合产流模型对闽江流域干流以上的15个子流域进行了模拟验证,进一步论证了这两种概念性流域水文模型结构的合理性,并得出了如下结论:大闽江流域,新安江模型与垂向混合产流模型都适用,且均能取得良好的效果。由于不同的洪水预报模型考虑产流机理的不同,采用的结构与参数不同,对不同洪水特征的计算结果也有差别,在实际使用中,设置不同结构的洪水预报模型是必要而且是有效的。同时,还对历史洪水根据其涨洪前段的实测流量过程与模型计算流量过程的确定性系数最大作为选择模型的标准,进行模型选择模拟预报。由此还得出另一个结论:在实时洪水预报中,根据不同的预知信息实时选择最佳的模型,能提高洪水预报的精度。     

抽水蓄能电站过渡过程仿真自动建模及通用程序

本文在改进文献中数学模型及有关连接方式的前提下引入结构形式参数，工况标识参数及部件动态计算模块化等，解决了按仿真对象及仿真工况的自动建模问题，编制的程序用于多个具有不同引水系统和参数的电站过渡过程仿真计算，证明有较强的通用性，灵活性和实用性。     

小流域产流产沙动力学模型

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。