[zerohm]

I remember a demonstration from my childhood where water is released into 2 similar models. One model is dry, one model is wet. The water quickly overtakes the dry model and splashes on the other side (as in a flash flood). On the wet model, water takes longer to make it to the other side. Sort of how a wet sponge is far more absorbent than a dry sponge.

I know I didn't really answer your question, but these models were made to represent fields and swamps. So yes, I believe there are lots of studies on large scale effects.