Evaluating Water Supply Risk in the Middle and Lower Reaches of Hanjiang River Basin Based on an Integrated Optimal Water Resources Allocation Model

Abstract

The rapid socio-economic development and expanding human-induced hydrological alteration have strengthened the interactions between the social and hydrologic systems. To assess regional water supply security under changing water supply and demand condition in strongly human-impacted area, an integrated water resources management model that fully incorporates water demand prediction, optimal water resources allocation and water supply risk analysis is proposed and applied in the mid-lower reach of Hanjiang River basin. The model is run under three scenarios considering increasing water demand and expanding water diversion projects, and then spatial and temporal distributions of water supply reliability and vulnerability are evaluated. Results show that water supply risk in the mid-lower reach of Hanjiang River basin, especially units that take water directly from the mainstream, will be gradually enlarged in the future due to the expansions of both water demand and inter-basin water diversion capacity. The proposed method provides a practical approach towards more robust decision-making of long-term water resources planning and management under changing environment.