A Modular Three-dimensional Finite-difference Ground-water Flow ModelScientific Publications Company, 1984 - 528 من الصفحات |
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عبارات ومصطلحات مألوفة
accumulator allocates space ANAME aquifer array values BUFF BUFFER calculated cell i,j,k cell-by-cell flow terms Chart for Module CNSTNT conductance between nodes constant-head cell containing CONTROL RECORD current stress period current time step DELC DIMENSION NCOL DIMENSION NCOL,NROW DOUBLE PRECISION equal to zero EVAPOTRANSPIRATION finite-difference equation flag Flow Chart flow field FORTRAN 66 FORTRAN 77 general-head boundaries Global Number grid HCOF head change HNEW hydraulic conductivity IBOUND ICBCFL is set Input IOFLG IPRN ISUM iteration parameters ITMP KSTP last stress period LAYCON List of Variables maximum number Module Index Narrative for Module NCOL,NROW,NLAY NROW Global Number of columns Number of layers Number of rows Output Control PRIMARY STORAGE Primary unit number printed or recorded printed output RATOUT recharge rate row direction secondary storage simulation specified starting heads submodule SUBROUTINE transmissivity U2DREL Variable Range variable-head cell Variables for Module VBNM VBVL volumetric budget X array
مقاطع مشهورة
الصفحة 3 - The use of firm, trade, and brand names in this report is for identification purposes only and does not constitute endorsement by the US Geological Survey For additional information write to: District Chief US Geological Survey 333 W.
الصفحة 7 - Kzz = the hydraulic conductivity along x, y and z coordinates which are assumed to be parallel to the major axes of hydraulic conductivity (LT~1); h = potentiometric head (L); W = volumetric flux per unit volume and represents sources and/or sinks of water (T~1); Ss = the specific storage of the porous material (L~1); and t = time (T).
الصفحة 8 - One such approach is finite-difference method, wherein the continuous system described by equation (1) is replaced by a finite set of discrete points in space and time and the partial derivatives are replaced by terms calculated from the differences in head values at these points. The process leads to systems of simultaneous linear algebraic difference equations; their solution yields values of head at specific points and times.
الصفحة 1 - ... incorporated in the modular structure of the computer program. The modular structure consists of a main program and a series of highly independent subroutines called modules. The modules are grouped into packages. Each package deals with a specific feature of the hydrologic system which is to be simulated, such as flow from rivers or flow into drains, or with a specific method of solving linear equations that describe the flow system, such as the strongly implicit procedure or slice-successive...
الصفحة 23 - Equation 7.6 cannot be solved independently, since it represents a single equation in seven unknowns. However, an equation of this type can be written for each active cell in the mesh; and, since there is only one unknown head for each cell, we are left within a system of n equations in n unknowns.
الصفحة 1 - ... describe the flow system, such as the Strongly Implicit Procedure or Slice-Successive Overrelaxation. The division of the program into modules permits the user to examine specific hydrologic features of the model independently. This also facilitates development of additional capabilities because new modules or packages can be added to the program without modifying the existing modules or packages. The input and output systems of the computer program are also designed to permit maximum flexibility....
الصفحة 1 - Ground-water flow within the aquifer is simulated using a block -centered finite-difference approach. Layers can be simulated as confined, unconfined, or a combination of confined and unconfined. Flow from external stresses, such as flow to wells, areal recharge, evapotranspi ration, flow to drains, and flow through riverbeds, can also be simulated.
الصفحة 2 - ... been released recently by the US Geological Survey, with McDonald and Harbaugh ( 1 984) as the major authors. The new code is a modular, three-dimensional finite-difference ground water flow model. The model was designed so that it could be readily modified, can be executed on a variety of computers, and is relatively efficient with respect to computer memory and execution time. The model's structure consists of a main program and a series of highly independent subroutines called modules. Each...
الصفحة 12 - Development of the ground-water flow equation in finite-difference form follows from the application of the continuity equation: the sum of all flows into and out of the cell must be equal to the rate of change in storage within the cell. Under the assumption that...
الصفحة 7 - Equation (1) describes groundwater flow under non-equilibrium conditions in a heterogeneous and anisotropy medium, provided the principal axes of hydraulic conductivity are aligned with the xy Cartesian co-ordinate axes. The groundwater flow equation together with specification of flow and/or initial head conditions at the boundaries constitute a mathematical representation of the aquifer system.