黄土高原典型淤地坝淤积机理研究

Study on Depositing Process of Check Dam on the Loess Plateau

在调查典型淤地坝挖取剖面采集土样的基础上,利用库容曲线和实测淤积厚度求得每层淤积泥沙量。根据大水对大沙的原则,反演淤积层所对应的次侵蚀性降雨。通过层淤积量与其相应次侵蚀性降雨的最大30 min降雨强度I30,降雨量P,降雨侵蚀力R,平均降雨强度I等4个指标的相关分析,结果表明,对于无泄洪设施的淤地坝坝地每层淤积量与次侵蚀性降雨的I30,P,R关系密切,并建立了淤积量与I30,P,R的三元回归方程,计算值与实测值拟合较好,从而为淤地坝水毁问题的研究提供了理论基础。

The deposited volume of each check dam layer was determined by investigating the status of check dams on the loess plateau, digging typical check dams, carrying out the sectional analysis, utilizing reservoir storage and measuring deposited thickness of a layer. Single erosive rainfall was ascertained according to the principle of ＂more rain, more sediment yield＂. Correlation analyses of deposited volume with the maximum rainfall intensity in＇thirty minutes （I30）, rainfall amount （P）, rainfall erosivity （R） and average rainfall intensity （I） were made, the result of which indicated close relationships among them. Relationships between deposited volume and the three indexes were then established. A good fitting plot between calculated result and observed data was found. The research offers a theory basis for the study of water-induced damage.