Consider the following statement:
"Implementing micro-irrigation in semi-arid regions always reduces total agricultural water withdrawals, because drip systems operate at significantly higher application efficiencies than traditional surface flooding."
Which of the following arguments identify a logical flaw or valid counter-evidence (Jevons' Paradox) in the reasoning above?
Options:
(A) Higher application efficiency may induce farmers to expand irrigated crop acreage or shift to more water-intensive high-value crops, ultimately increasing total water consumption
(B) Micro-irrigation systems reduce non-beneficial soil evaporation and deep percolation losses
(C) Saved water may be captured and reallocated to other consumptive uses within the watershed rather than remaining in regional aquifers
(D) Drip irrigation emitters require pressurized water and fine filtration
Answer Key:
A, C
Step-by-Step Solution & Explanation
The claim assumes that improved field-level efficiency automatically translates to reduced basin-scale water withdrawals. Options A and C point out known rebound effects / Jevons' paradox:
- (A) Efficiency gains lower the effective cost per unit yield, motivating farmers to expand acreage or grow thirstier crops, which increases aggregate water depletion.
- (C) Water 'saved' at field scale often reduces return flows that downstream users or ecosystems rely on, causing overall basin depletion to rise when captured for new uses.
- (B) and (D) are true factual statements but do not expose a logical flaw or counter-evidence to the conclusion.