Irrigation — Science definition
Supplying water to crops artificially through channels, sprinklers, or drip systems; it is the single largest human use of freshwater.
Where it is taught
- Water & Land Resources — Energy, Water & Material Resources, Physics & Environmental Science, Grade 12
In use
Irrigation can support crops but can deplete storage when withdrawals exceed recharge.
Water & Land Resources
Questions using irrigation
Problem 1
A river supplies 8 billion cubic meters of water per year, and agriculture takes 75% of it. A new efficient-irrigation program cuts agriculture's use by 20%. How many billion cubic meters does the program save per year?
Answer and explanation
1.2 billion m 3
Agriculture uses 0.75 x 8 = 6 billion m 3. A 20% cut saves 0.20 x 6 = 1.2 billion m 3 per year.