Fig. 3: Comparison of water footprint (WF) impact of quasi-decentralized system and totally centralized system.

a Diagram of the average WF of rice production in the whole of China for the two systems, b WF impact of the two systems in different rice-growing provinces. WF values in panel a are mean values with 90% probability ranges in brackets of the 9000 simulation results representing the variability of climate conditions and the uncertainty of nutrient retention parameters. Solid green, blue, and gray arrows are green, blue, and gray WF out of the system, in m3/ton; the dashed gray arrows indicate within system WF: * denotes WF for evapotranspiration from recycling usage of gray water, ** denotes gray WF from paddy fields to ditches and ponds. Note, the number of plants in the graph does not represent rice yield. Source data are provided as a Source Data file.