IGCSE Geography Agricultural Systems Practice Test 2026 – All-in-One Guide to Mastering Your Exam!

Heavy rainfall is the main trigger of soil erosion because the energy from moving water detaches soil particles and carries them away. When rain is torrential, the impact of raindrops breaks apart soil aggregates and quickly saturates the surface, creating strong surface runoff. That runoff flows downhill, picking up and transporting topsoil especially where vegetation cover is sparse, on bare fields, or along slopes. So the soil loss comes directly from the intense water movement caused by heavy rain.

Pasture burning can increase erosion risk by removing protective vegetation and litter, but it’s a management action rather than the primary cause. Steep slopes make erosion more likely by speeding up water flow and increasing runoff, but without the triggering rainfall, erosion wouldn’t move soil. Loose sandy soils are more susceptible because soil particles are less cohesive, so erosion is easier under rainfall, yet again the initiating factor is the rainfall delivering the energy to detach and transport soil.