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| Effects of precipitation and erosion control practices on the rainfall-runoff-sediment delivery relationships of typical
watersheds in the hilly-gully region on the Loess Plateau |
(1.College of Water Resources and Civil Engineering, China Agricultural University, 100083, Beijing, China;
2.Beijing Grandtopeak Tianpinghang Land Plan and Design Co., Ltd., 100873, Beijing, China; 3.State Key Laboratory of Soil Erosion
and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, CAS and MWR, 712100, Yangling, Shaanxi, China;
4.Tianshui Soil and Water Conservation Station, Yellow River Conservation Commission, 741000, Tianshui, Gansu, China) |
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Abstract Rainfall-runoff-sediment delivery relationship is of great importance for evaluating the benefits of erosion control practices in the hilly-gully regions on the Loess Plateau. The hydrologic data (1987—2010) of Qiaozi East Watershed (QE) with erosion control practices and Qiaozi West Watershed (QW) without erosion control practices were collected. We analyzed the annual variations of precipitation, runoff, sediment delivery and the annual sediment delivery per unit runoff of the watersheds using the Mann-Kendall test method. The double mass curve was used to analyze the runoff-sediment delivery relationship of QE and QW. The results indicated that the variation trends of runoff and sediment delivery of the watersheds were consistent with the precipitation, which was the main factor to influence the runoff and sediment delivery. No significant change was observed in the annual sediment delivery per unit runoff of QE during 1987—2006 and that of QW during 1987—2010, indicating that the variation in precipitation, slope erosion control practices and vegetation did not alter the runoff-sediment delivery relationship of the watersheds. However, a significant change occurred in QE during 2007—2010, after 19 check dams were built, resulting in reduction of gully erosion and alternation of the runoff-sediment delivery relationship.
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Received: 11 December 2012
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