Thalweg

The thalweg is the line connecting the lowest points of all cross sections in the longitudinal direction of a river, stream, channel or valley. In the aquatic free valleys he is with the " water collection line " identical; there often follow paths of his line.

The position of this line is not fixed in the aquatic environment, because fluctuating water levels, flow rates and sediment displacement fluctuations and displacements of the river bed and the position of the Talweges effect (see also: meander ). The thalweg shuttles between the shore lines of the water, so that its position usually does not coincide with the center line of the watercourse and usually not with the current line, the line connecting the points with the largest flow velocity at the surface (or little less). Depending on flow patterns and the seabed at the thalweg has branched waters do not run ( with river islands ) in the broadest branch of the river, but he runs there, where the flow has eroded the river bed at the lowest.

The location of the valley road is determined by soundings (bearing ) and shown in survey protocols and large-scale maps.