How Rivers Shape the Land
Rivers are nature's bulldozers, constantly wearing away and moving material through four main erosion processes. Hydraulic action forces water into cracks like a powerful wedge, whilst abrasion works like sandpaper as rocks scrape against riverbanks. Attrition smashes rocks together until they become smooth pebbles, and solution slowly dissolves certain rock types.
Transportation moves this material in different ways depending on size. Heavy boulders roll along the riverbed through traction, medium stones bounce along via saltation, and fine particles float in suspension. The finest material dissolves completely in solution.
Rivers create dramatic landforms through erosion. V-shaped valleys form where rivers cut straight down, creating steep sides with interlocking spurs that force the river to wind around them. Waterfalls develop when rivers flow over hard rock onto softer rock below, creating spectacular plunge pools.
๐ก Remember: Upper course = vertical erosion (cutting down), lower course = lateral erosion (cutting sideways).