冻融作用下高寒土细沟侵蚀过程与输沙能力经验模型OA

[Objective]This study aims to investigate the mechanisms by which freeze-thaw action affects rill erosion.[Methods]Laboratory flume scouring experiments were conducted to analyze rill sediment transport characteristics under different combinations of flow rate(q)and slope gradient(S),and sediment transport capacity factor models were constructed.[Results]1)Freeze-thaw action increased the sediment transport capacity of rills by up to 34.34%,with a pronounced dependence on slope gradient and flow rate.Additionally,it shortened the critical slope length from 6.8～8.1 m to 5.3～6.4 m.2)The sediment transport capacity maintained a linear relationship with flow rate(Tc=Aq)both before and after freeze-thaw processes,while its relationship with slope changed.Before freeze-thaw,it increased exponentially with slope(Tc=-ae(-S/b)+c),while after freeze-thaw,it followed a power-law growth(Tc=d Sf).The established models,Tc=-0.041 4+0.110 1S+192.5q before freeze-thaw and Tc=-0.039 8+0.107 7S+213.2q after freeze-thaw,exhibited high accuracy(R²=0.96).The changes in these coefficients indicated that the influence of flow rate on sediment transport capacity increased while that of slope decreased after freeze-thaw.[Conclusions]Overall,freeze-thaw action alters soil structure,enhances the sediment transport capacity of rills,and modifies the slope response relationship.Model comparisons indicate that freeze-thaw action,soil bulk density,soil type,and experimental settings all affect the prediction performance of the models.These findings provide important theoretical support for soil erosion prediction and control in alpine regions.