Select any one of the following surface processes: - Sea/marine action - River action - Glacial action - Mass movement Explain the formation of any two Irish landforms caused by your selected process with the aid of diagrams. - Leaving Cert Geography - Question Question 1 - 2007

River action refers to the processes of erosion, transportation, and deposition caused by the flow of water in rivers and streams. The energy of flowing water shapes the landscape, creating various landforms over time. Two notable Irish landforms resulting from river action are the River Valley and the Oxbow Lake.

1. Formation of the River Valley:

   • Erosion: As a river flows, it erodes the land through hydraulic action, abrasion, and corrosion. This leads to the widening and deepening of the river channel, forming a V-shaped valley.
   • Transport and Deposition: Sediments transported by the river are deposited during periods of low flow, leading to the formation of riverbanks and floodplains.

   

2. Formation of the Oxbow Lake:

   • Meandering: As a river meanders, lateral erosion occurs on the outside bends, while deposition takes place on the inside bends, leading to the growth of meanders.
   • Separation from the Main Channel: Over time, the meander neck narrows, and during a flood event, the river may cut through the neck, creating an Oxbow Lake, which is a crescent-shaped lake isolated from the main river channel.