Study On Water Quantity And Water Quality United-operation System Based On Ecosystem In The Lower Yellow River

Along with the fast development of economy in our country, the contradiction of water supply and demand and the problem of water pollution become more and more serious. It is now the most important thing of economic and social sustainable development's stratagem in our country that how to solve the problems of aquatic ecosystem and water environment, corresponding with economy-society-ecology-environment relationship.In this paper we studied ecological and environmental water demand in the lower Yellow River, and then ordered its definition and meaning. We divided ecological and environmental water demand into four parts: ecological water demand, water demand for sediment transport, water demand for pollution prevention, water demand for estuarine ecosystem protection, and calculated ecological and environmental water demand of every reach in the lower Yellow River. Based on the research of ecological and environmental water demand, a multi-reservoir optimal operation model considering ecological and environmental influences in the lower Yellow River was founded, then we compared and analyzed the results between the models that considering ecological and environmental influences and not; Aiming at the characteristic of heavy sediment load in Yellow River, we adopted a method that coupling Saint-venant equations with water quality transmitting empirical formula considering sediment factor in the lower Yellow River to research elementarily on water quantity and water quality model that can be applied to the lower Yellow River.Meanwhile, on the basis of before researches, the paper developed a water quantity and water quality united-operation system based on ecosystem in the lower Yellow River. The system is divided into three parts: database system, modelbase system and Human-machine intercommunication system. There are four main function:; in the system: (1) general water volume optimal operation in the lower Yellow River, (2) water volume optimal operation based on ecology and environment in ths lower Yellow River, (3) water quantity and water quality unite simulation in the lower Yellow River reaches. (4) GIS information searching in water system map of the lower Yellow River. The system can provide operation schemes of water quantity and water quality in the lower Yellow River, as well as other ralated information for decision-making persons. Then a case was given to validate the practicability of the system.