Cylindrical Grid Object Oriented Model for Pumping Test (COOMPuTe)

Conceptual model of radial flow converging to a pumped borehole

The Cylindrical grid Object Oriented Model for Pumping Test analysis COOMPuTe is a finite difference model designed to simulate groundwater flows converging to pumped boreholes. The model features simulating groundwater flows in confined and unconfined aquifers including a moving water table, a seepage face, well storage, and well losses. The model also has particle tracking capabilities enabling the delineation of the pathway of a contaminant under complex hydrogeological settings.

COOMPuTe is a layered cylindrical grid model prepared at the University of Birmingham with the support of the British Geological Survey.

Multiple layers and non-symmetry in the axial direction

Layered radial numerical grid

COOMPuTe can incorporate multiple layers of finite difference nodes in addition to discretisation in the radial direction. This allows the inclusion of aquifer heterogeneity, borehole seepage face and borehole partial penetration.

Confined or unconfined conditions with moving water table

The model simulates groundwater flows under either confined or unconfined conditions. A moving water table object is introduced under unconfined conditions. The moving water table reduces instabilities caused by the dewatering nodes.

Seepage face, well losses, borehole storage and partial penetration

Partially penetrating well can be included when multi-layer model is constructed. Under unconfined conditions, the model can represent the formation of seepage face when the water level inside the pumped borehole drops below the water table elevation at the borehole side. Under confined and unconfined conditions, the model can represent the borehole storage and well losses.

Recharge and additional abstraction

The model allows the inclusion of recharge or additional pumping from the aquifer. Recharge is added uniformly over the whole of the model area as mm/day and pumping can be specified at selected nodes as m3/day.

Rivers

River aquifer interaction can be included in the model through the representation of river as a set of leakage nodes. It is well acceptable that this type of models is not the best to deal with linear features as rivers, but this option is included in case the investigation of river aquifer interaction is necessary.

Particle tracking

Particle tracking is added to COOMPuTe to allow the simulation of the movement of an immiscible contaminant towards or away from a pumped well within complex hydrogeological settings.

Contact

Contact Dr Majdi Mansour for more information