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| Mechanism and effect of different contour hedgerow types on runoff and sediment erosion in Three Gorges Reservoir Area |
| Bu Chongfeng, Cai Qiangguo, Yuan Zaijian |
| Institute of Geographic Sciences and Natural Resources Research, CAS, 100101, Beijing,China |
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Abstract Five hedgerow-experimental-plots was established in 1993, data of runoff and soil loss under simulation rainfall and natural rainfall in each plot from 1994—1997 was collected to understand the benefits and mechanism of hedgerow to conserve water and soil. The results indicated that: Every plant hedgerow chosen has a big effect of conserving runoff and soil from 1994 to 1997. Soil loss reduction was 18.4%-70.0% (the average reduction was 29.7% in 1994 and 60.8% in 1997)and runoff reduction range from 17.2% to 70.8% (the average reduction was 33.7% in 1994 and 44.7% in 1997). And also Loriaria sinica and Vitex negundo played a more significant role in reducing runoff and soil erosion than Vetiveria zizanioides did, but the difference didn't reach to the statistical significant level different. The variations of runoff velocity in the hedgerow plot led essentially to the difference of soil losses. The runoff velocity in the upper slope of hedgerow strip decreased as the result of its obstruction and increased in the lower slope of hedgerow strip. Therefore, soil losses decreased greatly because of reduction runoff velocity and runoff amount between hedgerow's.
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Received: 18 December 2005
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