Emergy quantification of economic-social-ecological losses under water supply-demand dual regulation during mega-droughts

Scientifically quantifying the losses caused by supply-demand dual regulation measures under extreme drought conditions constitutes the fundamental basis for effectively addressing urban mega-droughts and mitigating their disaster impacts. To address the quantification of the comprehensive losses in regional ecological-economic systems resulting from bidirectional water supply-demand regulation under extreme drought conditions, this study introduces emergy theory to construct a loss quantification framework based on this approach. Specifically, on the supply side, it primarily considers the costs of tapping potential water sources and the resulting ecological and environmental damage, while on the demand side, it focuses mainly on the socio-economic losses due to water shortages and the negative ecological and environmental impacts caused by water use reduction. The framework is applied and validated using the case of the 2011 extreme drought in Chuxiong Prefecture, Yunnan Province. The results indicate that in Chuxiong Prefecture, the supply-side regulation cost was 4.76 × 1020sej, equivalent to 1.356 billion EmCNY based on the emergy/money ratio, while the demand-side water restriction loss was 3.58 × 1020 sej, equivalent to 1.019 billion EmCNY. The total economic-social-ecological loss from dual supply-demand regulation reached 2.375 billion EmCNY. In conclusion, the quantitative assessment of economic-social-ecological losses under dual-directional supply-demand regulation provides scientific support for extreme drought risk evaluation, government emergency response planning, and post-disaster recovery/reconstruction decision-making, thereby enhancing disaster prevention and mitigation capabilities.