Multistage integrated water security assessment in a typical region of Northwestern China

Abstract

Gansu Province in Northwest China faces serious water shortage, water pollution and fragile ecological environment, which have posed great threats to regional water security (WS). The WS assessment (WSA) is of great significance for regional sustainable development. In this study, WSA for 17 basins in the three regions (Yangtze River, Yellow River, and inland rivers) of Gansu Province in 2015, 2020, and 2030 was performed. Combined with relative carrying capacity (RCC) and integrated vulnerability (IV), a multistage integrated water security assessment (MIWSA) was proposed. The MIWSA controls the RCC and vulnerability in the water quantity and quality subsystems to achieve WSA of water resources system. Results show that the WS shifts from the security grade of the Yangtze River region in Southeast Gansu to the insecure grade of the inland river region in Northwest Gansu. Close internal relationship between WS, RCC, and IV makes a basin with high RCC grade and low IV grade have high WS grade. Measures and suggestions of water resource planning and management were proposed to improve regional WS grade. The MIWSA has good applicability and the ability to conveniently evaluate regional WS in the water resources system. Risk-based WSA in Gansu Province should be a potential research direction worth considering in future.