Building a FEMWATER Conceptual Model

A FEMWATER model can be created in GMS using one of two methods: assigning and editing values directly to the nodes and elements of a mesh (the direct approach), or by constructing a grid-independent representation of the model using feature objects and allowing GMS to automatically assign the values to the nodes and elements (the conceptual model approach). Except for simple problems, the conceptual model approach is typically the most effective.

The conceptual model approach utilizes feature objects in the Map module. A FEMWATER conceptual model is created in the Map module and feature objects are used to create a high level representation of the site you are modeling. The figure below shows a sample conceptual model.

Sample FEMWATER Conceptual Model

Two Step Process

A FEMWATER conceptual model is used to build a numerical model using a two step process. In the first step, a 3D mesh is created. This can be done by using the feature objects in conjunction with a set of TINs to build a 3D Mesh or a solid can be converted to a layered 3D Mesh using the Solids -> Layered Mesh command. In the second step, the boundary conditions and recharge values assigned to the feature objects are automatically assigned to the appropriate nodes and element faces of the 3D mesh using the Map -> Femwater command in the Feature Objects menu.