geography - rivers

• in the middle course there are meanders, oxbow lakes and flood plains. these are processes of erosion and deposition
• in the upper course there are vshaped valleys, interlocking spurs and waterfalls. these are all forms of erosion
• there are 3 stages of a river - the middle stage, the upper stage and the lower stage
• the river nile is the longest river in the world
• a watershed is an area of high ground which seperates two river drainage basins
• a drainage basin is an area of land drained by a river and its tributaries
• an estuary is the part of a river mouth that is tidal
• LEVEES - A structure built along the edge of a river to prevent flooding
• natural levees are made from alluvium
• levees are deposited on a floodplain as a result of flooding. During a flood, a river spreads out over the floodplain and loses speed. This causes the river to deposit its load. Larger, heavier sediment is deposited close to the riverbanks. Finer alluvium is deposited further out. After repeated flooding, the sediments build up to form levees along the riverbanks.
• an example of a levee is Along the river Barrow at Graiguenamanagh on the Kilkenny/Carlow border
• drumlin - an oval shaped hill made of boulder clay - feature of deposition