Option A Freshwater: Drainage basins and flooding
15 revision questions with answers for Option A Freshwater: Drainage basins and flooding, marked SL and HL. Read them here, or play the set as a class game on the projector. Free to host, and students join with a code.
Water soaking from the ground surface into the soil?
- InfiltrationRight answer
- Percolation
- Throughflow
- Interception
What this set covers
Water moving through a drainage basin and along a river is the subject. Infiltration, percolation, throughflow, overland flow, hydrograph features, the Hjulström curve, erosion and transport processes, and levees all feature.
- Common mix-up
- Students often confuse infiltration and percolation: infiltration is water entering the soil surface, while percolation is its downward movement from the soil into rock below.
- Revision tip
- Sketch a storm hydrograph, label rising limb, peak discharge, lag time and baseflow, then redraw it for an urban catchment and explain why the lag time changes.
All 15 questions and answers
Water soaking from the ground surface into the soil?
Answer: Infiltration
Downward movement of water from the soil into the underlying rock?
Answer: Percolation
Lateral movement of water downslope within the soil?
Answer: Throughflow
Water moving across the ground when rainfall intensity exceeds infiltration capacity?
Answer: Overland flow
Precipitation caught and held by vegetation before it reaches the ground?
Answer: Interception
Volume of water passing a point per second, measured in cumecs?
Answer: Discharge
Peak rainfall at 09:00 and peak discharge at 15:00: what is the lag time?
Answer: 6 hours
Part of a storm hydrograph showing discharge increasing after rainfall?
Answer: Rising limb
Steady part of a river's discharge, fed by groundwater seeping into the channel?
Answer: Baseflow
Graph of the velocities at which particles of different sizes are eroded, transported and deposited?
Answer: Hjulström curve
Why do clay particles need a higher velocity than sand grains to be eroded?
Answer: Cohesion
Transport of sand-sized particles in a series of hops along the bed?
Answer: Saltation
Erosion by a river's load grinding against its bed and banks?
Answer: Abrasion
Raised riverbank built up by deposition of coarser sediment during repeated floods?
Answer: Levee
Impermeable surfaces and drains in urban areas usually make a hydrograph's lag time…?
Answer: Shorter
Play it as a class game
Play this set opens it in splycr, where you can host it for your class straight away. Hosting needs no account: put the room code on the projector, and students join from a phone with the code and their first name. Each question plays as multiple choice, and the three wrong options were written for that question.