黄河上游宁蒙河段河道横断面形态对水沙变化的响应  

Responses of cross-section shapes to the variations of income water and sediment in Ningxia-Inner Mongolia Reach of the Yellow River

作　　者：董占地[1] 胡海华[1] 吉祖稳[1] 王党伟[1] 

机构地区：[1]中国水利水电科学研究院流域水循环模拟与调控国家重点实验室,北京100048

出　　处：《泥沙研究》2015年第4期20-25,共6页Journal of Sediment Research

基　　金：水利部黄河泥沙重点实验室开放课题基金资助项目(泥0135022013);水利部公益性行业科研专项经费项目(201401002);中国水利水电科学研究院科研专项项目(泥基本科研1540)

摘　　要：采用黄河上游宁蒙河段各水文站1965-2004年实测资料,分析了宁蒙河段河道横断面形态变化过程及其与来水来沙的响应关系。结果表明,宁蒙河段各典型断面具有平滩面积逐年减小和平滩宽深比逐年增加的趋势,且平滩面积均随年水量的增加呈增加趋势,但各断面各时段增加的程度不同,1986年以前增加的幅度较小,1986年以后,宁夏河段增加幅度较小,而内蒙河段增加幅度较大;宁蒙河段断面宽深比随年均来沙系数的增加呈增大趋势,其中宁夏河段增大的趋势不明显,而内蒙河段1986年以前随年来沙系数的增加而增大较小,1986年以后随年来沙系数增加而增大的趋势较为明显。由此说明,宁夏河段断面形态变化相对较小,趋于稳定,而内蒙河段断面形态随年来沙系数的增加而变得越来越宽浅,断面有向宽浅发展的趋势。通过宁蒙河段排沙比与来水来沙的响应关系分析,得出了宁蒙河段河道断面形态趋于稳定即河槽不冲不淤时临界水沙边界条件。Responses of cross-section shapes to the variations of income water and sediment in Ningxia-Inner Mongolia Reach of the Yellow River were studied by observed data at hydrological stations from 1965 to 2004. The results show that the typical cross-sections have a decrease trend of the bank-full area, and an increase trend of the width-depth ratio year by year. Bank-full areas increased with the water of the year;but each sec- tion of each period increased in different degree. Before 1986 ,each section increased significantly. The Ningx- ia Reach increased less,but the Inner Mongolia Reach increased greatly after 1986. The width-depth ratio en- larged with the increase of income sediment coefficient,and the increasing trend in the Ningxia Reach was not obvious,but the increasing trend in the Inner Mongolia Reach before 1986 was no more obvious than after 1986. Therefore,the cross-section shape variations of Ningxia Reach were relatively small and tended to be stable, but the cross-section shapes of Inner Mongolia Reach become more and more wide and shallow with the increase of income sediment coefficient. The critical water sediment boundary conditions of the cross-section shapes in Ningxia-Inner Mongolia Reach tending to be stable were obtained by analysis of the response rela- tionship between the sediment delivery ratio and the conditions of income water and sediment.

关 键 词：黄河 宁蒙河段 平滩面积 宽深比 排沙比 

分 类 号：TV147.2[水利工程—水力学及河流动力学]