SRT Hydrology and River Hazards 1 — Questions and Answers
Question 1: What is a strainer in a river environment?
- A submerged boulder
- A floating log
- An obstruction that lets water through but traps solids (Correct answer)
- A man-made water gate
Correct answer: An obstruction that lets water through but traps solids
A strainer is an obstruction, such as a fallen tree, that allows water to pass through but traps solid objects, posing a serious risk to rescuers and victims.
Question 2: Which river feature can recirculate objects or people indefinitely?
- Eddy
- Strainer
- Hydraulic (Correct answer)
- Undercut
Correct answer: Hydraulic
A hydraulic, or 'hole,' can trap and recirculate swimmers or objects due to the circulating water behind an obstacle.
Question 3: What is the term for water moving faster around a bend?
- Laminar flow
- Centrifugal flow (Correct answer)
- Counter flow
- Backflow
Correct answer: Centrifugal flow
Water on the outside of a bend moves faster due to centrifugal force, which increases erosion and hazard risk.
Question 4: Which hazard involves water flowing under a rock ledge or embankment?
- Hydraulic
- Eddy
- Undercut (Correct answer)
- Wave
Correct answer: Undercut
An undercut is where water flows beneath an overhanging rock or bank, posing a serious entrapment risk to swimmers.
Question 5: What is the safest position for swimming in moving water?
- Head down, feet behind
- Vertical floating
- Feet first on back (Correct answer)
- Face down freestyle
Correct answer: Feet first on back
Defensive swimming position, with feet first and on the surface, allows rescuers to see hazards and steer clear of obstacles.
Question 6: Why are eddies important in swiftwater environments?
- They pull swimmers underwater
- They speed up water flow
- They provide calm areas for rescue and rest (Correct answer)
- They form large waves downstream
Correct answer: They provide calm areas for rescue and rest
Eddies are calm areas behind obstructions where rescuers can rest, regroup, or stage a rescue plan.
SRT Hydrology and River Hazards 1
What is a strainer in a river environment?