Rivers and Landscapes
Ever wondered why rivers look so different from their source to the sea? Rivers are like nature's bulldozers, constantly eroding rock and soil as they flow downhill. Near the source in mountains, they're narrow and fast-moving with loads of energy to carve out steep valleys and create waterfalls.
The water cycle drives everything - precipitation falls as rain or snow, some gets caught by vegetation (interception), whilst the rest either soaks into the ground (infiltration) or flows over the surface as runoff into rivers. Plants lose water through their leaves (transpiration), sending moisture back into the atmosphere.
Rivers use four main ways to erode: hydraulic action (water force), abrasion (scraping), attrition (rocks smashing together), and solution (dissolving rock). They transport this material as bed-load (rolling boulders), saltation (bouncing rocks), suspension (floating particles), or dissolved chemicals.
Waterfalls form when hard rock sits above soft rock. The soft rock erodes faster, creating an overhang that eventually collapses. Over time, the waterfall retreats upstream, leaving behind a steep-sided gorge - like nature's own sculpture project!
Quick Tip: Remember erosion is wearing away, whilst deposition is dropping material - rivers erode in mountains but deposit near the sea.