干支流水沙对黄河内蒙古河道冲淤量的贡献率

Study on erosion and deposition in Inner Mongolia reach caused by runoff and sediment load from the Yellow River and its tributaries

根据大量实测资料,采用多元回归和偏相关分析等方法,分析了不同时期干支流水沙对黄河内蒙古三湖河口至头道拐河段冲淤量的贡献率。结果表明:1952-2012年长系列黄河干流径流量、输沙量和支流十大孔兑输沙量等3个影响变量对干流河道冲淤量的贡献率在汛期分别为20.6%、23.1%和56.3%;年内分别为24.8%、24.7%和50.5%。由此可以看出,十大孔兑来沙对该河段冲淤量影响最大,而干流水沙对该河段冲淤量影响程度相当。1960-1986年时段3个影响变量对冲淤量的贡献率分别为17.6%、17.4%和65.0%;而1987-2012年时段3个影响变量对冲淤量的贡献率分别为8.8%、14.7%和76.5%。由于1987-2012年时段干流来水量大幅度减少,从而导致十大孔兑来沙对该河段冲淤量影响程度进一步提高,贡献率达到76.5%。因此,要想减少该河段的淤积,首先要减少十大孔兑入黄沙量,其次要减少干流来沙和增加干流来水量。

Based on observation data,using multiple regression analysis and partial correlation analysis,A study is conducted on different contribution rates of erosion and deposition in the reach from Sanhuhekou to Toudaoguai in Inner Mongolia through runoff and sediment load in the Yellow River and its tributaries in different periods. Results indicate that contribution percentages of erosion and deposition through runoff and sediment load from the Yellow River and sediment load from ten tributaries,are 20. 6%,23. 1% and 56. 3% in flood season as well as 24. 8%,24. 7% and 50. 5% in annuals,respectively,in long series from 1952 to2012. The sediment load from ten tributaries affects the most significantly on erosion and deposition in this reach,but runoff and sediment load from the Yellow River have similar effect on contribution rate,less than that through tributary. Contribution rates of erosion and deposition through three affected variables are17. 6%,17. 4% and 65. 0%,respectively from 1960 to 1986 while the data are 8. 8%,14. 7% and 76. 5%from 1987 to 2012. It is further indicated that significant runoff reduce in the Yellow River contributes to the increase effect on erosion and deposition by sediment load from ten tributaries reach,which contribution rate is76. 5%. To decrease deposition in this reach,therefore,it is important to decrease sediment load from ten tributaries firstly and then to decrease sediment load and to increase the runoff from the Yellow River.