Young Blonde Girl Wet In The River

Studying the flows of rivers is one aspect of hydrology.
• Direction
A common misconception, particularly amongst schoolchildren and college students in North America, is that most, or even all, rivers flow from north to south. Rivers in fact flow downhill regardless of compass direction. Sometimes downhill is from north to south, but equally it can be from south to north, and usually is a complex meandering path involving all directions of the compass. Three of the ten longest rivers in the world - the Nile, Yenisei, and Ob - flow north, as do other major rivers such as the Rhine, Mackenzie, and Nelson.
Rivers flowing downhill, from river source to river mouth, do not necessarily take the shortest path. For alluvial streams, straight and braided rivers have very low sinuosity and flow directly down hill, while meandering rivers flow from side to side across a valley. Bedrock rivers typically flow in either a fractal pattern, or a pattern that is determined by weaknesses in the bedrock, such as faults, fractures, or more erodible layers.