Geography Junior Cert Exam - Rivers Topic
Key River Terms
- River Source: The beginning of the river.
- Watershed: Area where precipitation collects and drains into the river.
- Tributary: A smaller river that flows into the main river.
- Confluence: Point where a tributary meets the river.
- Estuary: Tidal part of the river.
- River Mouth: Part of the river that meets the sea.
Stages of a River
-
Youthful Stage
- Steep slope.
- Fast-moving water.
- Forms a V-shaped valley.
-
Mature Stage
- Gentle slope.
- Wide floor valley with gentle sides.
-
Old Age Stage
- Almost flat slope.
- Slow-moving, flat lowland.
Processes of Erosion
- Hydraulic Action: Moving water erodes riverbed and banks.
- Abrasion: Load (rocks and stones) scrapes the floor, deepening the river.
- Attrition: Load collides, breaking into smaller pieces.
- Solution: Chemicals dissolve rocks on the riverbed.
River Transport
- Rolling and Dragging: Moves heavy stones and rocks.
- Bouncing: Moves smaller stones and rocks.
- Suspension: Small stones and pebbles float in water.
- Solution: Tiny stones dissolve in water.
- Flotation: Leaves and sticks float on water surface.
Features of Rivers
Youthful River Features
- Interlocking Spurs: River flows around hills due to insufficient strength to erode them.
- V-shaped Valley: Formed by vertical erosion, weathering, and material falling into the river.
- Waterfall: Formed over hard rock next to soft rock, creating plunge pools.
- Examples: Niagara Falls, Victoria Falls, Angel Falls.
Mature River Features
- Meanders: Bends in a river where erosion occurs on the outer bend and deposition on the inner bend.
Old Age River Features
- Oxbow Lakes: Horseshoe-shaped lakes formed by river breaking through a meander.
- Levees: Ridges of alluvium along river banks formed by repeated flooding.
Human Interaction with Rivers
- Example: Dam Building in Ireland (e.g., Ardnacrusha on River Shannon)
- Benefits: Generates electricity.
- Disadvantages: Can flood fertile farmland.
This summary covers the essential information needed for the Junior Cert Geography exam on rivers. Be sure to review terms, stages, processes, and features thoroughly.