Comparison of numerical methods for simulating strongly nonlinear and heterogeneous reactive transport problems—the MoMaS benchmark case     

Jérôme Carrayrou  Joachim Hoffmann  Peter Knabner  Serge Kräutle  Caroline de Dieuleveult  Jocelyne Erhel  Jan Van der Lee  V. Lagneau  K. Ulrich Mayer  Kerry T. B. MacQuarrie 《Computational Geosciences》2010,14(3):483-502

Although multicomponent reactive transport modeling is gaining wider application in various geoscience fields, it continues to present significant mathematical and computational challenges. There is a need to solve and compare the solutions to complex benchmark problems, using a variety of codes, because such intercomparisons can reveal promising numerical solution approaches and increase confidence in the application of reactive transport codes. In this contribution, the results and performance of five current reactive transport codes are compared for the 1D and 2D subproblems of the so-called easy test case of the MoMaS benchmark (Carrayrou et al., Comput Geosci, 2009, this issue). This benchmark presents a simple fictitious reactive transport problem that highlights the main numerical difficulties encountered in real reactive transport problems. As a group, the codes include iterative and noniterative operator splitting and global implicit solution approaches. The 1D easy advective and 1D easy diffusive scenarios were solved using all codes, and, in general, there was a good agreement, with solution discrepancies limited to regions with rapid concentration changes. Computational demands were typically consistent with what was expected for the various solution approaches. The differences between solutions given by the three codes solving the 2D problem are more important. The very high computing effort required by the 2D problem illustrates the importance of parallel computations. The most important outcome of the benchmark exercise is that all codes are able to generate comparable results for problems of significant complexity and computational difficulty.  相似文献   

PROCESSES OF HEADCUT GROWTH AND MIGRATION IN RILLS AND GULLIES   总被引：1，自引：0，他引：1  

Kerry M. Robinson 《国际泥沙研究》2000,(1)

lINTRoDUCTIONHeadcuterosionwithinrills,ephemeralguIlies,classicgullies,andstreamscausesseriousenvironmentalproblems.Headcuterosionacceleratesthelossoftopsoilanddecreasestheproductivityofagriculturallands.Erodedsedimentsoftenendupinreceivingstreams,causingwaterqualityproblemsandnegativelyimpactingbioIogicalprocesses.Inadditiontolandscapedegradation,gulliesarethedominantformofdamagetoearthspillways.lfagullycanmovethroughanearthspillwayandbreachthecrestofadam,thentheimpoundedfloodwaterswiI1…  相似文献   

Quaternary palaeohydrological evolution of a playa lake: Salada Mediana, central Ebro Basin, Spain   总被引：3，自引：0，他引：3  

Blas L. Valero-GarcÉs  Antonio Delgado-Huertas  Ana Navas  Javier MachÍn  PenÉlope GonzÁlez-SampÉriz  & Kerry Kelts 《Sedimentology》2000,47(6):1135-1156

Sedimentary features, mineralogy, bulk geochemical composition, stable isotope analyses and pollen data from sediment cores were used to reconstruct the Late Quaternary depositional evolution of the Salada Mediana playa lake (central Ebro Basin, northeastern Spain). The 150-cm-long sediment core sequence is composed of gypsum- and dolomite-rich muds (Lower and Middle sections) and black, laminated, calcite-bearing sediments (Upper section). The Salada Mediana formed as a karstic depression in the Miocene gypsum substratum during the Late Pleistocene. The Lower section was deposited in a sulphate–carbonate saline lake that ended with a period of desiccation and basin floor deflation. Subsequent deposition (Middle section) took place in a playa-lake system. Two cycles of lower water table and expanded saline mud flats occurred. The Holocene sequence is missing, probably as a result of aeolian erosion. Sedimentation resumed only a few centuries ago, and saline pan environments dominated until modern times. The Salada Mediana facies succession was mainly governed by fluctuations in the hydrological balance, brine composition, and salinity; however, aeolian processes (detrital input and deflation) and recycling of previously precipitated salts also played a significant role.  相似文献