水土保持对黄河输沙量的影响

采用回归分析方法,研究水土保持对1954—2005年黄河年输沙量的影响。结果表明：1）从24个备选自变量因子中筛选出的由＂河口镇到吴堡区间7—8月降雨量＂＂水土流失治理度＂和＂ln‘河口镇到龙门区间年降雨量’＂3个自变量组成的多元非线性回归方程,相关系数达到0.883,在α=0.001的水平上高度显著,该回归方程＂解释＂了1954—2005年黄河年输沙量76.5%的变化;2）水土流失治理度能够很好地＂解释＂20世纪80年代以来黄河年输沙量减少的趋势;3）当河口镇到吴堡区间7—8月降雨量处于最大观测值时,水土流失治理度由0增加到50%,计算年输沙量减少幅度超过20亿t/a;4）治理程度相同时,水土保持对黄河年输沙量的影响是降雨量大的大于降雨量较小的。

Effect of soil and water conservation on sediment discharge in the Yellow River

This study was targeted to explore the effect of soil and water conservation on the annual sediment discharge in the Yellow River during the period of 1954 to 2005 using the regression analysis method. Results indicated that： 1） Three out of 24 optional independent variables,i. e.,＂rainfall from July to August in the section of Hekouzhen to Wubao＂,＂controlled percentage of soil erosion＂and ＂ln‘annual rainfall in the section of Hekouzhen to Longmen＇＂were screened out to form a multivariate nonlinear regression equation. The correlation coefficient（ R） reached 0. 883,highly significant at α =0. 001 level. The regression equation ＂explains＂76. 5% of the change of annual sediment discharge during the 1954—2005 period in the Yellow River. 2） Controlled percentage of soil erosion can be a good ＂explanation＂of the decline in annual sediment discharge in the Yellow River since the 1980 s. 3）When the July-August rainfall in the section of Hekouzhen to Wubao was at the maximum observed value,controlled percentage of soil erosion increased from 0 to 50%,and reduction rate of calculated annual sediment yield was over 2 billion tons. 4） At the same level of the soil and water conservation,the impact of soil and water conservation on the sediment load in the Yellow River in larger rainfalls is greater than that in smaller rainfalls.