Analysis of Dynamic Risk Transmission in Cascade Reservoirs Driven by Multi-Objective Optimal Operation

The numerous uncertainties in the process of water resource development and utilization bring multiple risks to water resource management. To enhance socio-economic benefits while considering ecological benefits, it is urgent to deeply explore risks. In this paper, Nuozhadu, Jinghong, and Ganlanba hydropower stations on the lower reaches of the Lancang River are taken as the objects. To balance the socio-economic and ecological benefits, a multi-objective optimization operation model was constructed. To describe the risk transmission, a VAR model was constructed, and the dynamic transmission among risks was explored. The results show that the ratio of ecological change is 10.38%, and the cascade power generation is 33,243 GWh (2% higher than the designed). The impacts of the perturbation for each risk on itself and others are quantitatively analyzed by the impulse response function. It is concluded that the transmission direction is generally positive, but the increase in ecological risk has negative impacts on risks of output and abandoned water, and risks of power generation and output also negatively affect abandoned water risk. Finally, the risk transmission is quantitatively estimated by the variance decomposition method. It is concluded that the power generation risk contributes most to the output and ecology risks, the ecological risk only contributes significantly to the abandoned water risk (the contribution rate is 6.30%), and the abandoned water risk contributes a lot to the others.