不同坡度对大别山区产流产沙的影响研究

Research on Impacts of Different Slope Gradients on Runoff and Sediment Yield in Dabie Mountains

大别山区是国家级水土流失重点预防保护区,针对大别山区水土流失问题,在霍山县水土保持试验站野外径流小区对2017年不同坡度的径流和泥沙监测数据资料进行分析,通过线性回归方程和典型降水事件分析大别山区产流产沙在不同坡度下产生的变化规律以及不同坡度对大别山区产流产沙的影响,为大别山区水土流失的预防与治理提供依据。研究发现:①在降雨量、雨强、降水历时条件相同的情况下,坡度对试验径流小区的产流产沙量影响较大,而降雨量对于不同坡度坡面产流产沙的影响具有延续特征;②在降雨量相同的情况下,坡度越大,坡面径流量越大,同时,坡面径流量与暴雨、大暴雨2种降雨强度相关性强,相关性系数均为0.52(>0.50);③坡面产沙量与降水强度相关性强,相关性系数为0.56(>0.50),其中大暴雨降雨强度对坡面产沙量影响最大,坡面产沙量来自这种降雨的比重大,占总沙量的92%。

Dabie Mountains is a national key prevention and protection area for water and soil loss.Aiming at the problem of soil and water loss in Dabie Mountains,and taking the field flow plot of the soil and water conservation test station in Huoshan County as an example,this paper analyzes the runoff and sediment data of different slopes in 2017,and discusses the variation rules of the runoff and sediment yield under different slopes in the Dabie Mountains,and the impacts of different slopes on runoff and sediment yield in the Dabie Mountains by the linear regression equation and typical precipitation events to provide basis for prevention and control of soil and water loss in Dabie Mountains.The results indicate that:①Under the same conditions of rainfall,rain intensity and precipitation duration,the slope gradient has a greater impact on the runoff and sediment yield of the test runoff plot.The effect of rainfall on the runoff and sediment yield on different slopes is continuous.②In the case of the same rainfall,the greater the slope is,the more slope runoff becomes.At the same time,the slope runoff has significantly correlation with the rainstorm and large rainstorm.Moreover,the correlation coefficient is 0.52,which is greater than 0.50 always.③The correlation between sediment yield and precipitation intensity is high,and the correlation coefficient is 0.56,which is greater than 0.50 always In addition,the precipitation intensity of large rainstorm has the greatest impact on the sediment yield on the slope,and the sediment produced under this condition accounts for 92% of total sediment.