Study Of The Ecological And Environmental Water Demand In Main Reach Of Yellow River

For nearly 20 years, along with instant development of economy and society in Yellow River Basin, overexploitation of water resources, increasing discharged pollutants, supply and require conflict of water resources and water pollution standing out day by day led to a series of problems such as frequently water interception, river channel shrinked, water quality deteriorated, spawning sites of fish degenerated, wetlands area in estuary shrinked etc.. This paper was grounded on identifying the basis characteristics of Yellow River ecosystem, emphasized the harmony of water resources, ecosystem and development of economy and society. With a view to the responding relation between Yellow River water resources and ecosystem, this study not only took nature attribute of water resources into account, but also emphasized on the important function water resources has to development of economy and society, defined conception and content of ecological and environmental water demand in the Yellow River, brought forward the essence water quantity to satisfy or maintain the function of Yellow River ecosystem. This paper give technique support to water resources management and unified attempered in the whole river and ecological and environmental water demand in riverway which is a urgent problem to be solved in water resources optimizing configure and water attempered of the Yellow River.Based on discussing present status of Yellow River water environment and ecology, using historical flow method, combined with ecological protection goals to deduce ecological and environmental water demand of the Yellow Rive, this paper put emphases on environmental water demand. According as water pollution characteristics of the Yellow River, choosing CODcr and ammonia nitrogen as main pollution control factors, this paper studied environmental water demand under three mode such as current pollution loading amount, controllable level of pollution and objective control. The coupling of ecological and environmental water demand is nodus in the study. This paper gave priority to ecological water demand of estuary inshore fishes and wetland in estuary delta, considered to satisfy water ecology and water environment function in each reach at the same time, and brought forward appropriate ecological water demand and minimum environmental water demand in 10 important hydrological sections of main reach on principles such as whole reach comprehensive consideration, water quality prior assurance and adjustable characteristic of water resources. This paper tentatively studied function, characteristic and ecological water demand of wetlands in downstream riverway too.