Comparative study between numerical and analytical groundwater modelling

Sammanfattning

This study compares analytical and numerical models for groundwater modelling. The focus of comparison is to investigate the change of the analytical results when there is only a partial penetration of the aquifer. Two methods of comparison are used, the first one consisting of calculating a radial distance from a shaft to the point where the drawdown is 0.3 meters with both models. The second method used was by comparing the radius of influence, which was determined through the numerical model as the radius inside which all groundwater recharge was transported to the shaft. The second method gave the best results as the models become more similar when examining the radius of influence through the groundwater recharge flow direction. There was only a slight difference in result, between the numerical and analytical method when there was a partial penetration with this method. The difference was deemed to be inside the margin of insecurity. However, this study has not verified that the analytical model can be used in all cases of partial penetration. It does however give an indication that it might be possible to use it for soils with high hydraulic conductivity, such as sand.