摘要
首先分析了水流塑造横剖面的机理。指出冲积河道洪水期间的冲刷是塑造横剖面的关键因素，并用长江荆江段观音寺水文站与监利水文站洪水期横断面变化资料予以说明，进而提出了第二造床流量的概念，即塑造河道横剖面的代表流量。利用两种挟沙能力公式，分剐计算了黄河下游4个水文站历年的第二造床流量，两者结果差别很小。平滩流量是第二造床流量的滞后表现，在径流量处于减少的趋势下，平滩流量滞后于第二造床流量，故后者要小于前者。资料分析表明：最大5d平均流量与第二造床流量关系密切，后者主要取决于洪峰，5～10d调水调沙期间的平均流量就是第二造床流量。平滩流量与第二造床流量的差剐，往往通过冲淤来表现；由第二造床流量和冲淤量推算的平滩流量与实际平滩流量也很相近。
It firstly analyzes the mechanism of flow-formed cross profile,points out that scour is the key factor for forming a cross profile of alluvial channel during flood season,explains it by using the data of cross section variation of Guanyinsi and Jianli hydrometric stations at Jinjiang section of the Changjiang River in flood season and then puts forward the concept of second bed-forming discharge,i.e.representative discharge for forming a cross profile.It calculates the second bed-forming discharge of 4 hydrometric stations over the years on the lower Yellow River respectively by using two formulas of sediment carrying capacity and the difference of the two results is very small.Bankfull discharge is the hysteresis of second bed-forming discharge and bankfull discharge delays second bed-forming discharge under the reduction tendency of runoff,thus the latter is smaller than the former.It shows through data analysis that maximum 5-day mean discharge is closely related with second bed-forming discharge,the latter mainly depends on flood peak and the mean discharge of 5-10 days during a regulated discharge regime of the river is second bed-forming discharge.The difference of bankfull discharge and second bed-forming discharge usually is shown by scour and fill and;the bankfull discharge calculated by second bed-forming discharge and scour and fill is very close to the actual bankfull discharge.
出处
《人民黄河》
CAS
北大核心
2009年第2期1-4,共4页
Yellow River
基金
水利部公益性行业科研专项(200801006)
关键词
第一造床流量
第二造床流量
平滩流量
黄河下游
first bed-forming discharge
second bed-forming discharge
bankfull discharge
the lower Yellow River
