Learning Terrain

Hmm. trying to find a easy n quick way to do some erosions where they should occur. This area is one of my favorites to go hike.
Im also having some trouble lining up the overlay 100%
I think its because UE4 starts disgarding information after a while considering i need to set my UV tiling value to 0.00046125461 and it doesnt appear to be very happy with that.

As a workaround im now painting out all rivers and obvious darker areas where transitions are prominent