Project background: Liaohe River Basin is short of water resources and has a high degree of exploitation and utilization and insufficient environmental flow guarantee; rapid economic and social development, high pollution load and heavy load control and management tasks; Liaohe River mainstream has serious water ecological degradation, with a wide gap with the restoration goal of Liaohe River Reserve and large difficulty in the restoration of water ecology. Liaohe River Basin is facing the scientific and technological demands of enhancement of water environmental quality up-to-standard control and environmental flow guarantee.

Main content: The studies on key technologies for environmental flow in Liaohe River Basin and application demonstration, key technologies for total capacity of Liaohe River Basin and application demonstration, key technologies for joint dispatching of water quality and quantity in Liaohe River Basin and application demonstration and key technologies for optimization and adjustment of water engineering layout for restoration of river natural ecosystem in Liaohe River Basin and application demonstration provide support for environmental quality up-to-standard and environmental flow management in Liaohe River Basin and provide common key technical support in the aspects of environmental flow and total capacity control for the water special landmark achievement of “basin water quality target management and monitoring and early warning technologies”.

Scale and Distribution of demonstration and popularization: A scientific and applicable monthly Environmental Flow Management Scheme for Liaohe River Basin has been proposed, which meets the water environmental protection needs and actual water use in Liaohe River Basin and is adopted for the management of water resources in the basin; the proposed Joint Regulation in Water Quality and Quantity’s Plan of Liaohe River Basin has been adopted by Liaoning Department of Water Resources Management for the regulation and practice of reservoir projects; Technical Guidelines for Ecological Regulation of Water Projects of Liaohe River Basin was established in Liaoning Bureau of Quality and Technical Supervision in 2017 and now has entered the Liaoning local standard solicitation procedure; Liaoning Province Water Resources Management Group adopted the project Joint Regulation in Water Quality and Quantity’s Plan of Liaohe River Basin to implement reservoir group ecological regulation in Taizi River Basin. The guaranteed rate of river environmental flow increased by 15-30% and the up-to-standard situation of environmental flow of control sections has been greatly improved than that before application demonstration. The control sections achieved the basic requirements of monthly up-to-standard during the demonstration period.

Main scientific and technological innovations and contributions: The platform, scheme and instruction manual have been adopted by the relevant department in Liaoning Province and the remarkable results have been achieved in the aspects of control section environmental flow and environmental quality of Liaohe River Basin reaching the standards.

Achievement and scientific and technological output: Four scientific and applicable schemes for environmental flow management, total capacity control, joint water quality and quantity regulation and optimization and adjustment of water project layout in Liaohe River Basin have been formulated. Five handbooks or guidelines have been compiled, including Guidebook on Environmental Flow Management, Guidebook on Ecological Regulation of Reservoirs and Gate Dams in Liaohe River Basin and Technical Guidelines for Ecological Regulation of Water Projects of Liaohe River Basin, and environmental flow guarantee management system of Taizi River Basin and total capacity management system of Liaohe River Reserve in Liaohe River Basin have been established, realizing the vocational operation. The demonstration of joint regulation in water quality and quantity of Huntai River Basin and decommissioning demonstration of water projects in Liaohe River Basin have been carried out.

Economic benefits: The environmental flow guarantee scheme of river basins and vocational operation of demonstration areas are of great supportive significance to the prevention and control of water pollution and water resources protection in the representative basin economic society.

Environmental benefits: The formation of the situation that the water environment in Liaohe River Basin is gradually improved has been accelerated and the increase in the quantity of water resources reaching the standard has increased the quantity of water resources that can be exploited and utilized locally and improved the guaranteed rate of water use for life, production and ecology in Liaohe River Basin of Liaoning Province.

Ecological benefits: The dam removal test was carried out. The reservoir dam was removed and the natural form of the river was restored. After restoration, the ecology in the river channel and riparian zone is gradually restored and the biodiversity has been improved.