分散性土体坡面冲刷侵蚀机理试验研究OA

Dispersive soil is highly sensitive to water and is prone to soil erosion,which seriously re-stricts the development of regional economies and the stability of ecosystems.Laboratory scouring ero-sion model tests were conducted to investigate the evolution characteristics of slope scouring erosion forms,runoff,and sediment yield under different slope gradients and flow rates,as well as their ef-fects on soil detachment rate,revealing the scouring erosion mechanism of dispersive soil slopes.The results showed that:(1)under the combined influence of slope gradient and flow rate,the evolution patterns of slope erosion and failure could be roughly classified into four modes:full-process sheet ero-sion mode on extremely gentle slopes under small to moderate flow,sheet erosion → rill erosion →shallow gully erosion mode on gentle or steep slopes under small flow,sheet erosion → rill erosion →shallow gully erosion-collapse mode on steep slopes under moderate flow,and rill erosion → shallow gully erosion-collapse mode on extremely steep slopes under moderate to large flow.(2)At the same slope gradient,runoff rate,sediment yield rate,and total sediment yield increased continuously with increasing flow rate.At the same flow rate,runoff rate showed no obvious change with increasing slope gradient,whereas sediment yield rate and the total sediment yield increased with increasing slope gradient.(3)During slope scouring erosion,soil detachment rate exhibited a linear relationship with flow rate and slope gradient(significant positive correlation),and the sensitivity of soil detach-ment rate to slope gradient was greater than that to flow rate.