黄土区土质道路径流水动力学参数的灰色关联度分析

黄土区土质道路路面侵蚀是该地区土壤侵蚀中的重要形式之一,为了探讨其土壤剥蚀率与径流水动力学参数的相关关系,以便为该地区道路土壤侵蚀预报模型的建立提供帮助,采用室内人工降雨及放水冲刷实验、灰色关联度分析方法研究了裸露土质路和植草土质路的径流水动力学参数与土壤剥蚀率间的关系,结果表明:1)在15°坡度、不同雨强条件下,可根据径流量或水流功率计算土壤剥蚀率;2)在2mm.min-1雨强、不同坡度条件下,可根据水流功率或坡度计算土壤剥蚀率;3)在降雨加放水冲刷试验条件下,裸露土质路的土壤剥蚀率可通过径流水深或径流流速计算得出,而植草土质路的土壤剥蚀率可通过过水断面单位能量或径流量计算得出。因此,在无汇水条件时,根据径流水流功率计算土壤剥蚀率较为合理;在有汇水条件时,采用径流量计算土壤剥蚀率较为合理。

Gray correlation analysis on hydraulic parameters of runoff on earth road of Loess area

Earth road erosion is one of the most important soil erosions on Loess area.Gray correlation analysis was performed to study the relationship between runoff hydraulic parameters and soil detachment rate on uncovered earth road and grass-covered earth road.The relationship would be helpful to the soil erosion prediction model.The results were as follows: 1) Soil detachment rate can be computed by runoff or stream power under different rain intensities at 15° slope;2) Soil detachment rate can be computed by stream power or slope under different slope at rain intensity of 2mm·min-1;3) Soil detachment rate of uncovered earth road and grass-covered earth road can be computed by runoff depth or runoff velocity,unit energy of water-carry section or runoff,respectively,under artificial rainfall and simulated overland flow test.Therefore,it is reasonable to compute soil detachment rate by stream power without runoff from upslope,and be computed by runoff with runoff from upslope.