APPENDIX G: QUALITY ASSURANCE FOR GROUNDWATER MODELS THROUGH DOCUMENTATION 

 Cape Cod Aquifer Management Project Final Report Page G-2 



Explain why the model being utilized was chosen. All simplifying 

 asumptions inherent to the application of the model should be stated 

 and justified, as well as the impact these assumptions may have on 

 model results. A comparison between these assumptions and actual 

 conditions should be made. Describe where model assumptions and actu- 

 al field conditions do not coincide and how this may affect model 

 results . 



5. Assignment of Model Parameters 



All initial conditions, boundary conditions, hydraulic and transport 

 parameter values should be defined and the reasons for selecting these 

 conditions justified. The values assigned throughout the modeled area 

 should be presented. The area covered by the model should be present- 

 ed as an overlay on a topographic base map of appropriate scale, high- 

 lighting boundary conditions and hydraulic parameter values. 



6 . Model Calibration 



Model calibration goals and procedures should be presented and dis- 

 cussed. The results of the final calibration run should be presented 

 and analyzed and departure from the calibration targets analyzed. The 

 effects of these departures on the model results should also be dis- 

 cussed. In addition, the overall model water and chemical balance 

 should be evaluated and the salient features of the model scenario 

 (pumpage, recharge, leakage, boundary conditions, etc.) highlighted in 

 this evaluation. 



7 . Sensitivity Analysis 



Model sensitivity analysis should be presented and interpreted. Dis- 

 cuss how well the model meets the purposes, goals and objectives stat- 

 ed in (1) above. Determine what parameters of the model have the 

 greatest influence on the model results. The analysis should focus on 

 those parameters based on the least certain assumptions. 



8. Model Validation 



Model validation goals and procedures should be presented and dis- 

 cussed. Model validation, or field validation, is defined as the 

 comparison of model results with numerical results, independently 

 derived from laboratory experiments or observations of the environment 

 (Reference No. 1). See Reference No. 1 for a more detailed descrip- 

 tion of validation procedures. 



The results of the final validation run should be presented and ana- 

 lyzed. Important points include departure from the validation targets 

 and the significance of these departures. Present and discuss the 

 overall model water and chemical balance, highlighting salient fea- 

 tures of the model scenario (pumpage, recharge, leakage, boundary 

 conditions, etc.). 



