what is the definition of thalweg
In geography and fluvial geomorphology, a thalweg or talweg (/ËtÉËlvÉÉ¡/) is the line of lowest elevation within a valley or watercourse.he thalweg thus marks the natural direction (the profile) of a watercourse. The term is also sometimes used to refer to a subterranean stream that percolates under the surface and in the same general direction as the surface stream.