How to predict how rains falls on a mountain and where and when that water will flow? That question is answered by hydrologists in models. This is one of those models, used by Powel ASA. I created this animation for them to help them explain the model they use. It's created entirely in Blender, using (among other) Particle Emitors (for the rain and snow), Fluid Simulator and the Cloud Generator (by Alan Dennis, RipSting)