Значение и использование
According to the National Research Council (1), model applications are useful tools to:
Assist in problem evaluation,
Design remedial measures,
Conceptualize and study groundwater flow processes,
Provide additional information for decision making, and
Recognize limitations in data and guide collection of new data.
Groundwater models are routinely employed in making environmental resource management decisions. The model supporting these decisions must be scientifically defensible and decision-makers must be informed of the degree of uncertainty in the model predictions. This has prompted some state agencies to develop standards for groundwater modeling (2). This guide provides a consistent framework within which to develop, apply, and document a groundwater flow model.
This guide presents steps ideally followed whenever a groundwater flow model is applied. The groundwater flow model will be based upon a mathematical model that may use numerical, analytical, or any other appropriate technique.
This guide should be used by practicing groundwater modelers and by those wishing to provide consistency in modeling efforts performed under their direction.
Use of this guide to develop and document a groundwater flow model does not guarantee that the model is valid. This guide simply outlines the necessary steps to follow in the modeling process. For example, development of an equivalent porous media model in karst terrain may not be valid if significant groundwater flow takes place in fractures and solution channels. In this case, the modeler could follow all steps in this guide and not end up with a defensible model.
1.1 This guide covers the application and subsequentdocumentation of a groundwater flow model to a particular site orproblem. In this context, “groundwaterflow model” refers to the applicationof a mathematical model to the solution of a site-specificgroundwater flow problem.
1.2 This guide illustrates the major steps to takein developing a groundwater flow model that reproduces or simulatesan aquifer system that has been studied in the field. This guidedoes not identify particular computer codes, software, oralgorithms used in the modeling investigation.
1.3 This guide is specifically written forsaturated, isothermal, groundwater flow models. The concepts areapplicable to a wide range of models designed to simulatesubsurface processes, such as variably saturated flow, flow infractured media, density-dependent flow, solute transport, andmultiphase transport phenomena; however, the details of these otherprocesses are not described in this guide.
1.4 This guide is not intended to be all inclusive.Each groundwater model is unique and may require additionalprocedures in its development and application. All such additionalanalyses should be documented, however, in the model report.
1.5 This guide is one of a series of standards ongroundwater model applications. Other standards have been preparedon environmental modeling, such as Practice E978.
1.6 This standard does notpurport to address all of the safety problems, if any, associatedwith its use. It is the responsibility of the user of this standardto establish appropriate safety and health practices and determinethe applicability of regulatory limitations prior to us
1.7 This guide offers anorganized collection of information or a series of options and doesnot recommend a specific course of action. This document cannotreplace education or experience and should be used in conjunctionwith professional judgment. Not all aspects of this guide may beapplicable in all circumstances. This ASTM standard is not intendedto represent or replace the standard of care by which the adequacyof a given professional service must be judged, nor should thisdocument be applied without consideration of a project's manyunique aspects. The word “Standard” in thetitle of this document means only that the document has beenapproved through the ASTM consensus process.