Physical geography is marked on mechanism. Not that deforestation increases flood risk, but why: less canopy means less interception, compacted soil means less infiltration, and water that used to be held reaches the channel faster, so the hydrograph peaks higher and sooner. Every question here asks for that chain rather than for the conclusion.
The feedback question is built to defeat the usual shortcut. Two of its four options carry the right label with the wrong mechanism — "positive feedback, as the system restores the original equilibrium" is a contradiction, and a student who has learnt only that melting permafrost is a positive feedback will still get it wrong. Knowing that positive means amplifying rather than beneficial is the whole point.
Elsewhere: which parts of the carbon cycle are stores and which are flows, and why calcium carbonate on the ocean floor is one and diffusion across the sea surface is the other. What a groyne does to the coast downdrift of it, which is where coastal management usually moves a problem rather than removing it. What forms a corrie. Why two magnitude-seven earthquakes kill fifty people and five thousand. Two data questions — a lag time and a percentage change taken against the right base — and one on what the Bradshaw model cannot tell you, where all three wrong options are things the model does in fact predict.
Catchments, bays and villages here are invented and the questions say so, so nothing rests on a place-specific fact that may have changed.
Nothing is taken from any exam board specification, past paper, mark scheme or textbook.
Zestly is an independent study tool. It is not affiliated with any exam board and it is not an exam centre.
Consider a feedback mechanism where rising global temperatures cause permafrost to melt, releasing methane into the atmosphere, which further increases temperatures. How should this be classified? — one of ten questions written for this set, alongside deforestation and discharge, carbon stores and flows, groynes, corries, hazard impact, hydrograph lag time and the limits of the Bradshaw model.
In the fictional catchment of River A, deforestation has removed 40 percent of the forest canopy. Which of the following best describes the immediate downstream impact on the water cycle within this catchment?
Increased peak discharge as water reaches the channel more rapidly
Deforestation reduces interception and evapotranspiration, meaning more water reaches the ground surface. Since the soil is less protected and infiltration is often reduced by compaction, surface runoff increases, leading to higher peak discharge. The error in the first option is confusing the loss of canopy with increased interception.