Retningslinier for opstilling af grundvandsmodeller

Summary and conclusions

Guidelines for groundwater flow modeling are proposed based upon modeling protocol that is widely accepted by the international hydrological community. The guidelines provide a framework within which issues relevant to model development, calibration, testing and predictive simulations should be conducted and reported. The guidelines can also be used to promote constructive dialog between the client and the consultant by clearly identifying up-front the issues most important to the modeling process. It is recommended that a series of meetings take place during the modeling study to review progress and milestones in the following areas:
Conceptual model development
Model setup and determination of calibration criteria
Calibration and validation
Simulations and uncertainty analysis

It is difficult to establish guidelines for all aspects of modeling due to lack of consensus or standard best practices. Further development of the modeling guidelines is dependent upon the need for better theoretical understanding and practical experience in the following areas:
Determination of performance criteria (required accuracy for calibration and validation)
Uncertainty analysis (data needs, methods for the quantification of uncertainty)
Application of solute transport models
Risk and cost-benefit analysis

It is recommended that the proposed guidelines be reviewed and updated within the next couple of years in anticipation of development in these areas.

These guidelines can to a large extent be applied to solute transport modeling in relatively simple, advective-dominated systems. However, the guidelines are not applicable to systems where solute transport is governed by complex chemical and biological processes. For example, the processes governing the transport of reactive solutes are not well understood. Therefore it is difficult to establish modeling guidelines for reactive transport when the fundamental conceptual and mathematical models describing relevant processes need further development.