Thalweg (; an English word compounded from the German elements Thal (since Duden's orthography reform of 1901 written Tal) meaning valley, and Weg, meaning way) is a term adopted into English usage for geography and geomorphology. It signifies the deepest continuous line along a valley or watercourse. In hydrology, the thalweg (sometimes called the "valley line") is a line drawn to join the lowest points along the entire length of a streambed or valley in its downward slope, defining its deepes… (More on Thalweg)