Is there a preferred method, or perhaps some trick to quickly develop 2d meshes with different "zones" of cell sizes? For example when modeling a reservoir and dam system, it can be desirable to dynamically model flow through the reservoir to capture the effects of attenuation. Typically I use a cell size on the order of 2-5 feet on and downstream of dams, but this is excessively fine for modeling a reservoir.
In some cases it would be easy to simply link a storage area, or a 2D area to a hydraulic structure on the dam, but in a particular model I'm working on, there are three open channel spillways which activate at different stages, and the entrance draw-down effects likely influence each other- so I'd like to model the dam and reservoir together. Ideally I'd like to have one big mesh with 2 foot cells around the dam and 50 foot cells out in the reservoir, but hand editing the mesh with the tools I'm aware of to accomplish this is not feasible. Any tricks out there folks have had success with?
I did try and make 2 separate meshes and link them together with a SA connection, which worked, but there is some anomalous stuff going on around the boundary conditions, and just doesn't seem as clean as using one big mesh.
Wow- this works wonders. Somehow I missed that you could change the cell size along breaklines. I will also try out the RiverGIS model in QGIS as I'd like to have a little more "control". For right now the breakline trick fits the bill. Thanks!