侵蚀细沟水力学特性及细沟侵蚀与形态特征的试验研究

Flume experiments for determining rill hydraulic characteristic erosion and rill patterns

本文进行了一系列水槽试验 ,研究不同长度的侵蚀细沟在坡度及入流量影响下的浅水水流水力学特性、侵蚀量及细沟的形态特征 .所采用的土壤材料为砂壤土 ,试验使用四种入流流量 ,四种坡度 ,四种细沟长度 .记录水流速度、沟宽及径流中的泥沙含量 ,并用多元回归方法分析了它们与坡度、入流量或它们的交互项之间的关系 .提出了一种数学模型来描述试验中沟宽的周期性形态变化 .提出了通过试验得出的不同细沟长度的产沙量来确定水流输沙能力的方法 ,并得出出测定输沙能力的采样长度为 2～ 4m 。

A series of flume experiments were conducted to understand shallow water hydraulics,erosion in rills as well as morphological patterns of a rill as effected by rill bed slopes and inflow rates.The soil used was Cecil soil,a sandy loamy soil.Four flow rates:3 8,7 6,11 4and 15 2 l/min and 4 slopes:1%,3%,5% and 7% were adopted in the experiments.The velocities.rill widths and sediment concentrations at the outlet were recorded and analyzed with multivariable regression method as functions of slopes,inflow rate and/or their interactive terms.Rill widths changing along the rill with certain periodical patterns were visulally observed.A mathematical model was advanced to describe these changing patterns of rill width.Sampling length for transport capacity was determined with the analysis of both sediment yields and width patterns.