Analytical and numerical analysis of tides and salinities in estuaries; part II: salinity distributions in prismatic and convergent tidal channels   总被引：1，自引：0，他引：1  

Kees Kuijper  Leo C. Van Rijn 《Ocean Dynamics》2011,61(11):1743-1765

Estuaries, commonly, are densely populated areas serving the needs of the inhabitants in multiple ways. Often the interests are conflicting and decisions need to be made by the local managers. Intake of fresh water for consumption, agricultural purposes or use by industries may take place within a region not far landward of the limit of salt intrusion. Human interventions (e.g. deepening of the navigation channels) or climate changes (sea level rise, reduction of the river discharge) can bring these intake locations within the reach of saline or brackish water and consequently endanger their function. To support policy and managerial decisions, a profound knowledge of processes associated with the salinity structure in estuaries is required. Although nowadays advanced numerical three-dimensional models are available that are able to cope with the complexity of the physics there is still a need for relatively simple tools for quick-scan actions in a pre-phase of a project or for instructive purposes. The analytical model described in this paper may serve these needs. It computes the maximum salinity distribution using the dispersion coefficient in the mouth as the only model parameter. The model has been calibrated using observational data in a large number of estuaries and experimental data in a tidal flume. The dispersion coefficient was successfully related to geometric and hydrodynamic parameters resulting in an expression that can be used for convergent estuaries as well as prismatic channels, see Eqs. 25a and 25b. Application of the model in a predictive mode showed its promising capabilities. Comparison with three-dimensional numerical models indicates that the channel geometry in the estuary mouth largely influences dispersive processes. The analytical model for salt intrusion may be used in combination with the analytical model for tidal propagation in convergent estuaries and tidal channels by Van Rijn (part I). In this way, input is obtained on the tidal velocity amplitude and the Chézy roughness following calibration of this model on tidal amplitudes along the estuary.  相似文献   

3D Marchenko applications: implementation and examples     

Joeri Brackenhoff  Jan Thorbecke  Giovanni Meles  Victor Koehne  Diego Barrera  Kees Wapenaar 《Geophysical Prospecting》2022,70(1):35-56

We implement the 3D Marchenko equations to retrieve responses to virtual sources inside the subsurface. For this, we require reflection data at the surface of the Earth that contain no free-surface multiples and are densely sampled in space. The required 3D reflection data volume is very large and solving the Marchenko equations requires a significant amount of computational cost. To limit the cost, we apply floating point compression to the reflection data to reduce their volume and the loading time from disk. We apply the Marchenko implementation to numerical reflection data to retrieve accurate Green's functions inside the medium and use these reflection data to apply imaging. This requires the simulation of many virtual source points, which we circumvent using virtual plane-wave sources instead of virtual point sources. Through this method, we retrieve the angle-dependent response of a source from a depth level rather than of a point. We use these responses to obtain angle-dependent structural images of the subsurface, free of contamination from wrongly imaged internal multiples. These images have less lateral resolution than those obtained using virtual point sources, but are more efficiently retrieved.  相似文献   

Multipath analysis of code measurements for BeiDou geostationary satellites   总被引：7，自引：2，他引：5  

Guangxing Wang  Kees de Jong  Qile Zhao  Zhigang Hu  Jing Guo 《GPS Solutions》2015,19(1):129-139

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Balancing exploitation and conservation of the eastern Scotian Shelf ecosystem: application of a 4D ecosystem exploitation index     

Bundy  Alida; Fanning  Paul; Zwanenburg  Kees C.T. 《ICES Journal of Marine Science》2005,62(3):503-510

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An ELLAM approximation for advective–dispersive transport with nonlinear sorption     

Matthew W. Farthing  Christopher E. Kees  Thomas F. Russell  Cass T. Miller 《Advances in water resources》2006

We consider an Eulerian–Lagrangian localized adjoint method (ELLAM) applied to nonlinear model equations governing solute transport and sorption in porous media. Solute transport in the aqueous phase is modeled by standard advection and hydrodynamic dispersion processes, while sorption is modeled with a nonlinear local-equilibrium model. We present our implementation of finite volume ELLAM (FV-ELLAM) and finite element (FE-ELLAM) discretizations to the reactive transport model and evaluate their performance for several test problems containing self-sharpening fronts.  相似文献   

Wavefield extrapolation and amplitude-variation-with-angle migration in highly discontinuous media   总被引：4，自引：0，他引：4  

Jianfeng Zhang  Kees Wapenaar 《Geophysical Journal International》2003,155(1):327-339

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Versatile Two-Level Schwarz Preconditioners for Multiphase Flow     

C.E. Kees  C.T. Miller  E.W. Jenkins  C.T. Kelley 《Computational Geosciences》2003,7(2):91-114

Numerically modeling groundwater flow on finely discretized two- and three-dimensional domains requires solution algorithms appropriate for distributed memory multiprocessor architectures. Multilevel and domain decomposition algorithms are appropriate for preconditioning or solving linear systems in parallel and have, therefore, been applied to linear models for saturated groundwater flow. These algorithms have also been incorporated into more complex nonlinear multiphase flow models in the context of a linearization procedure such as Newton's method. In this work, we study a class of parallel preconditioners based on two-level Schwarz domain decomposition applied in a nonlinear two-phase flow numerical model. The restriction and interpolation operators are based on an aggregation approach that has a straightforward implementation for a variety of applications arising in subsurface modeling: structured and unstructured discretizations, finite elements and finite differences, and multicomponent model equations. We present model formulations, results from numerical experiments, and a comparison of a standard one-level Schwarz method to three two-level aggregation-based methods.  相似文献   

Inexact Newton methods and the method of lines for solving Richards' equation in two space dimensions     

Michael D. Tocci  C.T. Kelley  Cass T. Miller  Christopher E. Kees 《Computational Geosciences》1998,2(4):291-309

Richards' equation (RE) is often used to model flow in unsaturated porous media. This model captures physical effects, such as sharp fronts in fluid pressures and saturations, which are present in more complex models of multiphase flow. The numerical solution of RE is difficult not only because of these physical effects but also because of the mathematical problems that arise in dealing with the nonlinearities. The method of lines has been shown to be very effective for solving RE in one space dimension. When solving RE in two space dimensions, direct methods for solving the linearized problem for the Newton step are impractical. In this work, we show how the method of lines and Newton-iterative methods, which solve linear equations with iterative methods, can be applied to RE in two space dimensions. We present theoretical results on convergence and use that theory to design an adaptive method for computation of the linear tolerance. Numerical results show the method to be effective and robust compared with an existing approach.  相似文献   

Progress in Geodynamics: (Proceedings of the national symposium on Geodynamics held in Amsterdam,April 3–4, 1975). G.J. Borradaile,A.R. Ritsema,H.E. Rondeel and O.J. Simon (editors). North-Holland,Amsterdam, 1975, 245 pp., US$ 24.95     

Kees A. De Jong 《Tectonophysics》1977,37(4):364-366

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Colonial auks and eiders as potential indicators of oil pollution     

Kees Vermeer 《Marine pollution bulletin》1976,7(9):165-167

Colonial auk (Alcid) populations can be used as indicators of the effects of oil pollution on the seabirds of Canada's coastal zones. Of approximately 11 million breeding colonial alcids in Canada and in adjacent West Greenland waters, 87% are murres. Common Eiders may serve as the best indicators of the effects of oil pollution in Canada's western Arctic where colonial alcids are scarce.  相似文献