The 3D Geological Modeling of the Milk River Transboundary Aquifer: Challenges and Solutions
In this context, the Geological Survey of Canada has launched MiRTAP (Milk River Transboundary Aquifer Project) in order to produce a unified hydrogeological model of the aquifer and make recommendations for the sustainable management of this shared resource. The Milk River Aquifer had already been studied during the 20th century; however, most of the previous studies were limited by the international border, preventing a sound and complete understanding of the aquifer dynamics.
A prerequisite for the hydrogeological model is the three-dimensional geological model of the aquifer. The building of the transboundary 3D geological model implies dealing with many diverse geological data, which do not have the same units or spatial reference. On a regional scale, many stratigraphies coexist; the geological formations are neither named nor recognized in the same way and may not include the same geological members on both sides of the border. Therefore, finding the equivalent geological and hydrogeological strata in the two countries could be challenging.
In the case of the Milk River Aquifer, a unified 3D geological model has been developed. It covers 50,000 km2. The harmonization and unification of various sources of geological data was needed to build this uninterrupted 3D model, including the testing of a few new hypothesis not studied before. This model forms the basis of the future numerical hydrogeological model of the transboundary aquifer.