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选取黄土高塬沟壑区砚瓦川流域作为研究对象,分析综合治理前后年水沙关系及次降雨水沙关系变化及其对流域治理的响应,研究结果表明:1997年为砚瓦川流域减水减沙作用明显生效的转折年。治理期(1998—2009年)与基准期(1981—1997年)相比,无论年尺度还是次降雨尺度上,径流深与输沙模数间的关系均发生显著变化,其单位径流输沙量显著降低。其中在次降雨尺度上水沙关系趋于稳定的临界径流深为3 mm;当降雨量<50 mm、雨强<4 mm/h或历时>3 h时,治理期较基准期水沙关系变化显著。水土保持综合治理是造成年尺度和次降雨尺度上水沙关系变化显著的原因,并且可以显著降低中低降雨量、中低雨强和中长历时降雨的单位径流输沙量。
The Yanwa-Chuan basin in the gully region of the Loess Plateau was selected as the research object. The relationship between the annual water-sediment and the relationship of the secondary rainfall and sediment after the comprehensive management and the response to the watershed management were analyzed. The results showed that in 1997, The role of sediment reduction noticeable turning-point years. Compared with the baseline period (1998-1999), the relationship between runoff depth and sediment transport modulus both changed significantly at the annual and sub-rainfall scales. The unit of sediment discharge Significantly lower. Among them, the critical runoff at which the relationship between water and sediment tends to be stable at sub-rainfall scales is 3 mm. When the rainfall is less than 50 mm, the rainfall intensity is less than 4 mm / h or the duration is more than 3 h, Significant. The comprehensive management of soil and water conservation is the reason of significant change in the relationship between water and sediment at the annual and sub-rainfall scales, and can significantly reduce the medium and low rainfall, moderate and low rainfall intensity and long-term rainfall of unit runoff.