Dietary transitions for urban water sustainability in arid regions: A planetary health case study from Ürümqi, China

We develop an integrated domestic water-conservation framework combining dynamic water pricing with healthy-diet interventions to jointly manage physical and virtual water use. (Virtual water refers to the total interregional flow, through trade, of water consumed in the production of traded products.) Relative to the baseline diet, healthy, vegetarian and meat-based diets reduced annual per-capita food water footprints (The water footprint quantifies the total water use associated with consumption by an individual, region or country.) by 166.11, 208.42 and 167.97 m 3 , respectively, and industrial water footprints by 14.95, 22.05 and 15.17 m 3 through supply-chain linkages, while direct domestic water use remained largely unchanged. Dynamic water pricing reduced annual per-capita shower water use by 10.58–15.88 m 3 and total domestic water use by 42.32–83.58 m 3 . Acceptance differed between interventions: 41.67% supported water-price regulation, mainly influenced by consumption habits, whereas 53.57% accepted dietary adjustment, with willingness more strongly associated with ethnicity and income. After accounting for acceptance rates, the three dietary scenarios reduced city-wide annual food water footprints by 370, 464 and 374 million m 3 and industrial water footprints by 33, 49 and 34 million m 3 , respectively. Dynamic water pricing reduced annual urban water use by 73–145 million m 3 , including 18–27 million m 3 of shower water. Water pricing therefore primarily affects direct domestic use, whereas dietary adjustment propagates upstream through supply chains, generating broader water-footprint effects. This framework advances domestic water conservation towards coordinated social–ecological governance of physical and virtual water, offering a transferable pathway for water-scarce cities.