植被恢复对黄土丘陵沟壑区产流模式的影响研究

Study on the Effect of Vegetation Restoration on Runoff Pattern in Gullied Rolling Area

探究植被恢复对产流模式的影响是认识变化环境下流域水文及水土流失过程的基础。通过分层原位双环土壤入渗试验和植被恢复前后流域实测场次洪水过程解析,研究植被恢复对黄土丘陵沟壑区典型小流域产流模式的影响。研究结果表明:植被恢复显著增强了土壤入渗性能,0~60 cm不同深度土层的入渗速率均有不同程度的增大。植被恢复增大了表层土和10 cm土层入渗性能的差异。土壤入渗性能随土壤密度减小和孔隙度增大而显著增强,植被恢复通过降低土壤密度和增大孔隙度影响土壤入渗和产流过程。植被恢复后小流域场次洪水的洪峰流量、径流深、径流系数以及地表径流占比均减小,壤中流增加,产流模式从超渗产流向蓄满产流转变,形成黄土高原特有的浅层蓄满产流模式。植被恢复影响了流域的产流模式,为深入研究黄土高原土壤水文过程提供了科学依据。

Investigating the impact of vegetation restoration on changes in runoff generation patterns is essential for understanding watershed hydrology and soil erosion processes in a changing environment.This study examined the influence of vegetation restoration to the runoff gen⁃eration patterns in a typical small watershed in the gullied rolling loess area through stratified in⁃situ doublering infiltration tests and the analysis of the measured flood process before and after vegetation restoration.The results show that (a)vegetation restoration has significantly en⁃hanced soil infiltration capacity,resulting in varying degrees of increase in the infiltration rate at different depths(0-60 cm).Vegetation restoration has increased the difference in infiltration capacity between the surface soil and the 10 cm layer.(b)Soil infiltration capacity increases significantly with a decrease in soil bulk density and an increase in porosity.Vegetation restoration can affect soil infiltration and runoff generation processes by reducing soil bulk density and increasing porosity.(c)After vegetation restoration,the peak flow,runoff depth,runoff coefficient and surface runoff ratio of storm events in the small watershed are decreased,while subsurface runoff is increased.The runoff generation pattern is shifted from excessive infiltration to saturated runoff.These findings indicate that vegetation restoration has an impact on the runoff generation patterns and provide a scientific basis for further studying soil hydrological processes in the Loess Plateau.