Predicting the Water Rebound Effect in China under the Shared Socioeconomic Pathways

Area of Science:

• Environmental Science
• Resource Economics
• Hydrology

Background:

• The rebound effect is observed in energy and irrigation, but its impact on total water use remains unclear.
• Previous studies predicted resource use under Shared Socioeconomic Pathways (SSPs), lacking specific analysis on China's water use rebound.

Purpose of the Study:

• To investigate the existence and extent of the rebound effect in China's total water use.
• To evaluate water resource and economic status across Chinese provinces under different SSPs.
• To simulate future water use efficiency changes and their impact on total water consumption.

Main Methods:

• Utilized hydro-economic (HE) classification for provincial water resource and economic assessment.
• Employed conditional convergence models and FAO-recommended methods to simulate water use efficiency changes under SSPs.
• Integrated SSPs, Cobb-Douglas production function for GDP forecasting, and water use efficiency forecasts to calculate total water use changes from 2016-2030 for 31 provinces.

Main Results:

• Water use efficiency in China's provinces is projected to increase continuously.
• Despite efficiency improvements, total water use exhibited a
• U
• -shaped trend across different SSPs.
• The study confirms a rebound effect in China's total water use under various socioeconomic scenarios.

Conclusions:

• The rebound effect is evident in China's total water use, challenging assumptions of linear water savings from efficiency gains.
• Findings highlight the need for integrated policies addressing both water use efficiency and total consumption.
• Recommendations are provided for advancing irrigation water-saving technologies and policies to mitigate the rebound effect.