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地下水数值模拟常受到模型不确定性、观测资料不确定性等多种不确定性因素的影响,对这些影响因素进行定量分析十分必要。将差分进化自适应梅特罗波利斯(Differential Evolution Adaptive Metropolis,DREAM)算法与MODFLOW模型结合应用于地下水数值模拟不确定性的定量分析。以模型结构概化、水位观测资料误差这两种重要不确定性来源为例,通过一个理想地下水流模型,系统分析两者对模型参数及模型输出结果不确定性的影响。研究结果表明:模型结构概化及水位观测资料误差共同引起了地下水数值模拟的不确定性,但模型结构概化起到了主控作用。模型结构概化合理时,模型参数及模型输出结果的不确定性较小,并随观测资料误差不确定性的增大而增大;模型结构概化不合理时,模型参数及模型输出结果主要受控于模型结构概化带来的影响,且不确定性显著增大;观测资料误差相同情况下,模型结构概化越接近于真实的水文地质条件,模型参数及模型输出结果的不确定性越小。 相似文献
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以长江中下游防洪系统为对象,将面向长江中下游防洪规划论证需求的水沙数学模型转化为面向长江防洪系统防汛方案评估需求的长江中下游蓄泄关系实时评估数学模型.为适应实时蓄泄评估快速、准确的要求,提出了基于水动力学的循环滚动计算模式、实时校正模式和实时防洪调度的试验机制.实现了水文学实时校正方法与水动力学数学模型的耦合,建立了基于水动力学的实时校正模式.为了满足长江中下游江湖蓄泄关系实时评价的需求,探讨了洪水模拟与分蓄洪调度模式的耦合.通过长江中下游防汛期间的试运行,较好地解决了防洪措施蓄泄关系评估和工程优化调控模式等关键难题,为防洪规划方案的制定和实时洪水调度方案优化提供了定量的依据,主要成果已应用于长江中下游防洪规划和防汛调度方案中. 相似文献
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塔里木河干流河道水均衡模型研究 总被引:3,自引:0,他引:3
通过对河道水面蒸发量、渗漏量、漫溢量的分析,建立了以月为单位的塔里木河干流河道水均衡模型.该模型以阿拉尔来水量为输入,输出包括干流主要水文站点的水量、各河段的蒸发量、渗漏量、漫溢量等.利用1981—1995年逐月的水文资料进行了模型参数率定,以1996—2000年的水文资料进行了模型验证,结果表明模型具有较好的适应性.利用该模型分析塔里木河干流水资源转化消耗的规律,得出河道漫溢尤其是中游的漫溢是塔里木河干流主要的水量消耗.考虑堤防建设对模型进行了修正,并利用修正后的水均衡模型分析了堤防建设的影响. 相似文献
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雨量站网布设会影响径流模拟精度,研究不同雨量站密度和空间分布的径流响应规律对提高径流模拟精度和减小不确定性具有重要意义。应用新安江模型和HBV(Hydrologiska Fyrans Vattenbalans)模型,以湘江流域为研究对象,采用贝叶斯方法比较分析在不同雨量站密度及空间分布下径流模拟的不确定性。结果表明:增加雨量站密度可以降低面雨量的估计误差,使模型在不同的雨量站空间分布下具有较高的模拟精度;通过优化雨量站空间分布,可以减小雨量站网布设导致的模型不确定性,从而提高径流模拟精度;在相同的降雨输入和参数采样方法下,新安江模型和HBV模型对降雨输入导致的不确定性响应规律具有相似性,但是本研究结果显示在湘江流域新安江模型的模拟精度更高,而HBV模型的不确定性更大。 相似文献
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以长江中下游防洪系统为对象,概述了在大型复杂防洪系统洪水行为数值模拟基础上,成功地将长江中下游洪水演进数学模型转化为面向长江防洪系统防洪规划方案评估需求的长江中下游江湖水沙演变的数学模型.为适应防洪规划方案论证涉及江湖水沙相互制衡相互关联客观情况,建立了面向江湖水沙关系及其演变的数学模型.针对长江中下游江湖水沙运动特点,在水沙数值模拟的范围内侧重对下荆江河道冲刷、荆江三口分流分沙模式、洞庭湖泥沙淤积、江湖耦合等环节进行了讨论,提出了合理可行的数值处理方法.模拟结果较好反映了江湖水沙演变规律,主要成果已应用于长江中下游防洪规划和防汛调度方案中. 相似文献
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On the development of a model of the thermo-mechanical-hydraulic behaviour of unsaturated soils 总被引:3,自引:0,他引:3
The development of a model of the thermo-mechanical-hydraulic behaviour of unsaturated soil is described. A step by step approach is adopted, taking as a starting point a potential-based model of coupled heat and moisture transfer. Extensions of this work to include the effect of air transfer and the deformation characteristics of the soil are presented. Constitutive relationships which accommodate non-linear elasticity, thermoelasticity and elasto-plasticity are considered. Numerical solutions of the various versions of the model are presented. Validation of the versions of the model, at their differing stages of development, is considered in turn and results presented in support of each case. The need for further, on-going research is also suggested, with a view towards resolving remaining problems of concern in safety assessment. 相似文献
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近年来,概念性水文模型在水文预报中得到了广泛应用,为探讨SIMHYD模型在松花江流域应用的适应性,为其汛期的防洪控制、水库调度提供依据,本文选择嫩江流域上游石灰窑断面和第二松花江流域白山断面汛期(6—9月)的日径流过程进行模拟。计算结果表明,SIMHYD模型在松花江流域的应用中存在区域性差异:在嫩江流域上游石灰窑汇水区,率定期的纳什系数为0.501,验证期的纳什系数为0.158,模型应用的适应性较差;在第二松花江流域白山汇水区,率定期的纳什系数为0.777,验证期的纳什系数为0.729,模型应用的适应性优良。模型对于洪峰处的模拟存在较大误差,主要原因在于该模型没有考虑到产流时空分布不均及河道汇流计算过程。 相似文献
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Suksun Horpibulsuk Martin D. Liu Deepa S. Liyanapathirana Jirayut Suebsuk 《Computers and Geotechnics》2010,37(1-2):1-9
In this paper, the mechanical properties of cemented clay are studied. The theoretical framework of the Structured Cam Clay (SCC) model is extended to describe the behaviour of cemented clay. The SCC model is modified to take into account special features of the behaviour of cemented clay. The widely used mean effective stress parameter is modified to include the influence of cementation on the strength and the plastic deformation of cemented clay. A new destructuring function is also suggested to represent the removal of the cementation structure, especially in the formation of the final failure state for artificially strongly cemented clay. The revised model is then employed to simulate and predict the behaviour of cemented clay with various degrees of cementation and confining stresses. The main features of the complicated behaviour of cemented clay can be reasonably represented well by the theoretical framework of the SCC model. Finally, the influence of cementation on the model parameters is discussed, and empirical equations are proposed to determine some of the key model parameters for engineering practice. 相似文献
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对新安江模型蒸散发计算的改进 总被引:4,自引:1,他引:4
基于DEM构建数字流域水文模型,在此基础上,利用新安江模型作径流计算。利用陆面模式SSIB中大气动力阻抗法计算蒸散发的方法改进新安江模型的蒸散发计算,从而改进新安江模型对流域出流量的模拟,得到更为合理的陆面水文模型。以安徽水阳江流域为研究区域,利用改进前后的新安江模型进行径流模拟。结果表明,对新安江模型蒸散发计算的改进提高了模型对径流量的模拟效果。 相似文献
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Mahnoosh Biglari Claudio Mancuso Anna d’Onofrio Mohammad Kazem Jafari Ali Shafiee 《Computers and Geotechnics》2011
Existing models for predicting the small strain behaviour of unsaturated soil are not capable of predicting the initial shear stiffness during suction reduction under normally consolidated conditions. This problem has been addressed in the present study by combining an existing elastoplastic model and recent experimental data to provide a new model for the initial shear stiffness. The model, which is similar to that typically adopted for saturated soils, uses the average skeleton stress and an additional function of the degree of saturation. This new model not only captures the behaviour of the new experimental results, but it also describes a unique relationship between saturated and unsaturated soils. 相似文献
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Klaus G. Nickel 《International Journal of Earth Sciences》1981,70(3):1164-1176
Some Permian calc-alkaline rocks of the Saar-Nahe-Basin are briefly described and their origin is discussed in the light of a magma-mixing model for the intermediate members. The model is based on high trace element concentrations of Ni, Cr, Rb, Sr, Zr and Nb, straight-line chemical variations, mineralogical features and stratigraphie sequence of the volcanic rocks. The model is in accord with a geodynamic model for the Hercynian belt as suggested by Lorenz & Nicholls (in prep.). 相似文献