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| Effect of soil and water conservation on sediment discharge in the Yellow River |
| Li Min |
| Upper and Middle Yellow River Bureau, Yellow River Conservancy Commission of the Ministry of Water Resources, 710021, Xi‘an,China |
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Abstract 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 1980s. 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.
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Received: 30 November 2013
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