A river is a natural Flowing water channel Source to Mouth it goes Me-anders down and grows With main stages three Upper, Middle, Lower. Sea? [Break] Upper stage from Source Is where it all begins From rain, melting snow Or sub-surface springs [Break] Downward rock erosion rules From high water energy Waterfalls and rapids Valleys shaped like a ‘V’ [Break] Now, there’s four erosion Processes to mention: [Break] Rocks scraping the riverbed? Corrasion or Abrasion Just worn down by water force? That’s Hydraulic Action [Break] When rivers are acidic? Rocks see Dissolution Colliding smaller, rounder? That we call Attrition [Break] A river is a natural Flowing water channel Source to Mouth it goes Me-anders down and grows With main stages three Upper, Middle, Lower. Sea? [Break] Middle stage slopes les Its channel gets more wide Water volume rises as Tributaries join beside [Break] Sideways bank erosion rules Of soil, silt, sand, and clay Floodplains start to form, as Depposition joins the fray [Break] Me-anders are the curves In channel of river Outer side eroded Seddi-munt dropped inner [Break] In time, their necks grow thin Which a flood will break Silt isolates the curve; Now an oxbow-lake [Break] A river is a natural Flowing water channel Source to Mouth it goes Me-anders down and grows With main stages three Upper, Middle, Lower. Sea? [Break] Lower stage near Mouth is Almost flat, wider still Water volume peaking To lake and ocean fill [Break] Depposition dominates Landforms you might see Are delta, estuary Oxbow lake, and levee [Break] A Delta is where river Mouth Meets slow-moving sea Landform oft triangular From seddi-munt silty [Break] But an estuary Connects to stronger sea; Is water body salty Enclosed by land partly [Break] And as for a levee, that’s To river parallel It’s a wall, silty Built by floods, slowly [Break] A river is a natural Flowing water channel Source to Mouth it goes Me-anders down and grows With main stages three Upper, Middle, Lower. Sea? [Break] When water enters rivers Faster than can flow downstream Channel banks are broken With floods at the extreme [Break] If river slopes are steep And ground beneath is hard When come heavy rains, for floods We should be on guard [Break] Hard engineering helps But soft ways are the best: Forests slow the water And absorb excess
