Answer (i) or (ii) - Leaving Cert Geography - Question 28 - 2019

Formation of Landform 1: A Delta

Diagram: A labeled diagram showing the formation of a delta at the mouth of a river.

A delta forms when sediment carried by a river is deposited as the river meets a standing body of water, such as an ocean or lake. This process is facilitated by the slowing of the river's flow, which reduces its capacity to carry sediment. The accumulation of sediment creates land that protrudes into the body of water.

1. Named Landform: Delta
2. **Two Aspects: **
   • Aspect 1: The river's mouth showing sediment deposition.
   • Aspect 2: Aerial view of a delta formation.
3. Formation Explained:
   • Sediment Load: Rivers carry sediment which accumulates at the river's mouth.
   • Distributaries Formation: The river splits into smaller channels, forming distributaries that distribute water and sediment across the delta.
   • Vegetation Growth: As sediment builds, vegetation may take root, stabilizing the delta and encouraging further accumulation.

Formation of Landform 2: A Sand Dune

Diagram: A labeled diagram showing the formation of a sand dune in a desert.

Sand dunes form due to the accumulation of sand transported by wind in arid and coastal environments. The wind lifts and moves sand grains, which eventually settle, creating various shapes of dunes, such as crescent-shaped barchans or linear dunes.

1. Named Landform: Sand Dune
2. Two Aspects:
   • Aspect 1: Wind direction illustrating the movement of sand.
   • Aspect 2: Cross-section view showing the internal structure of the dune.
3. Formation Explained:
   • Wind Action: Consistent wind direction abrades and transports loose sand particles.
   • Obstacles: Natural barriers like vegetation cause sand to accumulate, forming hills or mounds.
   • Dune Migration: As wind continues to transport sand, the dunes can shift, resulting in changes in their shape and size.