Showing papers in "Techniques and Methods in 2005"
TL;DR: In this article, the authors propose a novel approach to solve the problem of homonymity in homophily, and propose a solution to the problem: homophysphysics.
Abstract: ............................................................................................................................................1 Chapter
1,518 citations
TL;DR: This report documents the computer codes UCODE_2005 and six post-processors, which can be used with existing process models to perform sensitivity analysis, data needs assessment, calibration, prediction, and uncertainty analysis.
Abstract: This report documents the computer codes UCODE_2005 and six post-processors. Together the codes can be used with existing process models to perform sensitivity analysis, data needs assessment, calibration, prediction, and uncertainty analysis. Any process model or set of models can be used; the only requirements are that models have numerical (ASCII or text only) input and output files, that the numbers in these files have sufficient significant digits, that all required models can be run from a single batch file or script, and that simulated values are continuous functions of the parameter values. Process models can include pre-processors and post-processors as well as one or more models related to the processes of interest (physical, chemical, and so on), making UCODE_2005 extremely powerful. An estimated parameter can be a quantity that appears in the input files of the process model(s), or a quantity used in an equation that produces a value that appears in the input files. In the latter situation, the equation is user-defined. UCODE_2005 can compare observations and simulated equivalents. The simulated equivalents can be any simulated value written in the process-model output files or can be calculated from simulated values with user-defined equations. The quantities can be model results, or dependent variables. For example, for ground-water models they can be heads, flows, concentrations, and so on. Prior, or direct, information on estimated parameters also can be considered. Statistics are calculated to quantify the comparison of observations and simulated equivalents, including a weighted least1 International Ground Water Modeling Center and the Colorado School of Mines, Golden, Colorado, USA 2 U.S. Geological Survey, Boulder, Colorado, USA 3 U.S. Geological Survey, Lakewood, Colorado, USA 4 Department of Earth Sciences, University of Aarhus, Aarhus, Denmark
271 citations
261 citations
TL;DR: A method for extending the capabilities of MODFLOW-2000 by incorporating the ability to simulate unsaturated flow beneath streams, and a third hypothetical simulation is presented that includes interaction between a stream and aquifer separated by an unsaturated zone.
Abstract: Many streams in the United States, especially those in semiarid regions, have reaches that are hydraulically disconnected from underlying aquifers Ground-water withdrawals have decreased water levels in valley aquifers beneath streams, increasing the occurrence of disconnected streams and aquifers The US Geological Survey modular ground-water model (MODFLOW-2000) can be used to model these interactions using the Streamflow-Routing (SFR1) Package However, the approach does not consider unsaturated flow between streams and aquifers and may not give realistic results in areas with significantly deep unsaturated zones This documentation describes a method for extending the capabilities of MODFLOW-2000 by incorporating the ability to simulate unsaturated flow beneath streams A kinematic-wave approximation to Richards’ equation was solved by the method of characteristics to simulate unsaturated flow beneath streams in SFR1 This new package, called SFR2, includes all the capabilities of SFR1 and is designed to be used with MODFLOW-2000 Unlike SFR1, seepage loss from the stream may be restricted by the hydraulic conductivity of the unsaturated zone Unsaturated flow is simulated independently of saturated flow within each model cell corresponding to a stream reach whenever the water table (head in MODFLOW) is below the elevation of the streambed The relation between unsaturated hydraulic conductivity and water content is defined by the BrooksCorey function Unsaturated flow variables specified in SFR2 include saturated and initial water contents; saturated vertical hydraulic conductivity; and the Brooks-Corey exponent These variables are defined independently for each stream reach Unsaturated flow in SFR2 was compared to the US Geological Survey’s Variably Saturated Two-Dimensional Flow and Transport (VS2DT) Model for two test simulations For both test simulations, results of the two models were in good agreement with respect to the magnitude and downward progression of a wetting front through an unsaturated column A third hypothetical simulation is presented that includes interaction between a stream and aquifer separated by an unsaturated zone This simulation is included to demonstrate the utility of unsaturated flow in SFR2 with MODFLOW-2000 This report includes a description of the data input requirements for simulating unsaturated flow in SFR2
183 citations
30 citations
TL;DR: In this article, the authors propose a method to solve the problem of homonymity in homonym identification, i.e., homonymization, in the context of homology.
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11 citations