Evolution mechanisms and fundamental equations of social water cycle fluxes

Abstract

Abstract The rise of socio-hydrology, addressing the interactions between human and water systems, is regarded as an innovative perspective to researches achieving the sustainable use of water resources. Revealing the social water fluxes, in terms of magnitude, structure, and variations under changing environment, could advance the understanding of water cycling under the dual driving forces: natural and anthropogenic. This study attempts to formulate the fundamental equations of the social water cycle by focusing on the evolution mechanisms of social water cycle fluxes. The endogenously dynamic characteristics of social water cycling are portrayed, i.e., the gradual change mechanism and the catastrophe mechanism, therefore dividing the evolution processes into four stages. Then, social water cycle flux reaches its peak and completes the first stage of evolution. The evolution process is an S-shaped curve process. After the peak, it enters the next evolutionary stage, where the pattern varies with the intensities of the gradual change mechanism and the catastrophe mechanism. The coordination relationships of these two mechanisms and the fluctuating characteristics in each stage are studied as well. Case studies are investigated in 39 countries globally to verify the fitting of the fundamental equations and evolution mechanisms.