Worksheets › Class 11 › Landforms and their Evolution › Cheat sheet
Class 11 Landforms and their Evolution: cheat sheet
CBSE Social Science. The landforms carved and built by running water, groundwater, glaciers, waves and wind, and the stages of a river landscape.
Key ideas
- Youth: few streams, shallow V-shaped valleys, waterfalls and rapids; maturity: deep V-valleys and wider floodplains; old age: meanders, levees and ox-bow lakes near sea level.
- Running water carves gorges, canyons, potholes and plunge pools, and builds alluvial fans, deltas, floodplains, natural levees and point bars.
- Groundwater in limestone makes karst: sinkholes, uvalas, lapies and caves with stalactites and stalagmites.
- Glaciers carve cirques, horns and U-shaped valleys, and leave moraines, eskers, drumlins and outwash plains.
- High rocky coasts have cliffs, wave-cut platforms and stacks; low sedimentary coasts have beaches, bars, spits and lagoons.
- Wind in deserts makes pediments, pediplains, playas, mushroom rocks and dunes such as barchans and seifs.
Remember
| River gradient | fall in metres ÷ length in km = m per km (steeper suggests youth) |
| Glacier or cliff movement | metres = cm per day (or year) × days (or years) ÷ 100 |
| Gorge or canyon? | gorge: near-vertical sides, same width top and bottom; canyon: step-like sides, wider at the top |
| Stalactite or stalagmite? | stalactites hang from the roof; stalagmites rise from the floor |
| Moraines | terminal at the toe, lateral along the sides, medial in the centre, ground as a sheet of till |
| Barchan | crescent dune with wings pointing downwind |
Watch out
- Mixing up stalactites and stalagmites.
- Calling a spit, delta or moraine erosional: they are deposits.
- Forgetting to divide by 100 when turning cm into metres.
Worked example
Suppose a valley glacier moves 50 cm a day. (a) How many metres does it move in 260 days? (b) How many cm in a week? (c) Name two depositional landforms the glacier leaves when it melts.
Working: 50 × 260 ÷ 100; 50 × 7
Answer: (a) 130 m (b) 350 cm (c) moraines and eskers (also drumlins and outwash plains)
Practise Landforms and their Evolution
Revise with this page, then practise: every Landforms and their Evolution sheet in the app is new, with an answer key and working.
Coming soon for Android and iPhone.