Landforms in the tropics

H2 Geography - syllabus 9173, 2027

Explain how rocks, slopes and rivers change, then connect those processes to tropical karst, meanders, braided channels and deltas.

• Chemical weathering processes

  Chemical weathering changes or dissolves minerals where the rock sits, and the reaction depends on the water and the minerals.

• Physical weathering processes

  Physical weathering breaks rock into pieces without changing its minerals, and each process needs particular conditions.

• Controls on tropical weathering

  Climate sets the conditions for weathering, but rock type, water, living things, time and people decide how fast it works.

• Falls, flows, creep and slides

  Mass movement happens when gravity's downslope pull is greater than the strength holding the slope together, and rain can do both.

• Splash erosion, rainwash and rillwash

  Raindrops knock soil loose, water flowing over the surface carries it away, and concentrated flow cuts small channels called rills.

• River erosion and sediment transport

  Rivers erode and carry material in several ways, and dissolved minerals travel in the water even when it looks clear.

• River energy and deposition

  A river deposits material when it can no longer carry part of its load, but different particles drop out at different times.

• Cockpit karst and tower karst

  Karst forms where water dissolves limestone, and rock structure, drainage and time decide whether cones, hollows or towers remain.

• Caves and speleothems

  Water dissolves limestone to form caves, and changes in the water's chemistry then deposit calcite as speleothems inside.

• Karst ecosystem services and human pressures

  Karst provides water, habitats and cultural value, but its underground drainage lets damage spread far beyond where it starts.

• Meanders, river cliffs and point bars

  A meander moves sideways as its outer bank erodes and its inner bank builds up, driven by how water swirls around the bend.

• Braided channels and mid-channel bars

  Rivers become braided when they carry lots of sediment, have changing flows and easily eroded banks, creating shifting bars.

• Delta formation and coastal processes

  A delta grows where a river deposits sediment at its mouth faster than waves, tides and currents remove it.

• Delta services and human pressures

  Deltas support millions of livelihoods through sediment, fresh water and wetlands, but activities upstream and on the delta can weaken these services.

• Named examples: Landforms in the tropics

  A named place with a date or figure, linked to your point, turns a general answer into a developed one.