Study On Environmental Flow In The Lower Yellow River

Water environment of human life has provided more and more restrainingconditions to the production, and living. With the improvement of environmentalprotection consciousness,"Environment Flows" has been introduced to the relatedresearch on river basins as the research hotspots. As the mother river of China, theYellow River, has a direct impact on about30%of the Chinese population, andmoreover, the management of the Yellow River comes along with all the economicdevelopment of the city. Scientific and reasonable study on the environment flow ofYellow River is conducive to the sustainable and healthy development of theeconomy.At present, the environmental flow studies have been developed from the globallarge-scale and macroscopic angle to microscopic angle, and realized the transitionfrom perspective focusing on the water the size to the water quality, and ecologicalenvironmental protection. Related scholars in China has conducted numerous studieson this, but because of language differences and the biased professional studies, in theprocess of environmental flow in a river basin, a recognized systemic concept of theenvironmental flow has not been formed, with each related subject always sided onthe research part. There are more related studies on the environment of the YellowRiver basin scale as a whole and aggregate flow problem, but the local small scaleresearch in detail on the lower reaches of the Yellow River is less. As to this situation,based on the lower reaches of the Aishan~Lijin as the main research, through theanalysis of basic hydrological data, discussion has been conducted from two aspectsof river, river water quality, water quantity, and the ecological environment indifferent time scales. On the basis of the in-depth study of related theories andliterature, the author has boldly divided the river environmental flow into the floodseason flow and the non-flood ecological flow as the water research focus; besides,the author has conducted controlling variable research studies about the river’sself-purification requiring; the author study the instream biological water quality requirements, from the typical fishes’ living environment. At the same time, localparameter adjustments have been made on the existing calculation method andformula for river environmental flow, which has made the formula more suitable forthe actual situation in the study area. Based on the System Dynamics Model, researchthe water for domestic, irrigation, million industrial value-added requirements andurban greening as the river outside flow. Comprehensively given the basin riversection in river flow requirement, different periods of environmental flowrequirements both inside and outside environment of Aishan, Luokou&Lijin havebeen put forward.It is shown that the more frequent study of the human activity along the river hascaused the fact that the years of runoff in hydrology can no longer use the relevantdata and time of the1950s far away from now. The average value of theenvironmental flow in the channel selection in recent30years is more in line with thecurrent research status.Comprehensively connecting with the conditions of the ecological base flow, theflood sediment, the river self-purification, the Coilia ectenes’s migration, and etc., themost appropriate annual environmental flow is24.917billion m3~27.655billion m3for Aishan~Lijin; the annual90%reliability of the runoff is10.418~16.047billionm3; the average annual evaporation water demand is of about1.880million cubicmeters; the most suitable sediment environmental flow in flood season is16.535billion m3~19.273billion m3; monthly average of the self-purification water demandin Aishan and Lijin are79.83m3/s,41.50m3/s respectively. The river water qualitystatus in2004~2014is good that we don’t need to computation dissolved oxygen inbiological water requirements of River. Comprehensive the outside environmentalflow’s demand, the study area’s flow in the most suitable range of26.633billionm3~31.171billion m3.