东北黑土区野外模拟降雨条件下产流产沙研究

Research on Runoff and Erosion Sediment Under Simulated Rainfall Conditions of Black Soil in Northeast China

对不同坡度(3°,5°,7°,9°,12°,15°)的径流小区,采用野外人工模拟降雨试验方法,对不同降雨强度(1.24,1.87,2.17mm/min)黑土坡地产流和产沙随雨强和时间的变化特性进行模拟试验。通过对模拟降雨试验数据分析,得出结论:①同一坡度下,产流时间随雨强的变化具有明显的规律性,雨强越大,产流所需的时间越短。②累计产沙量随累计径流量的增加呈幂函数增加,满足y=AxB函数形式(定义A为产沙基数系数,B为产沙速率系数)。③侵蚀产沙量随含沙量的增加呈线性增加,其表达式满足y=ax+b形式,系数a体现了产沙能力。④随着雨强的增大坡面径流量也增大;随着坡度的增大坡面径流量呈现先减小后增加,最后减小的趋势。⑤随着雨强的增大,坡面侵蚀产沙量基本呈现增加的趋势;而随着坡度的增加,坡面侵蚀产沙量变化复杂,12°～15°之间存在试验条件下的临界坡度。

The artificial rainfall test method that about the runoff and sediment varies along with the rainfall intensity and time under different slope（3°, 5°, 7°, 9°, 12°, 15°） runoff test plots and different rainfall intensities（1.24, 1.87, 2.17 ram/rain） was used. The conclusions were as follows： （2）Runoff time had an obvious regularity with the change of rainfall intensity, and it decreased with increasing rainfall intensity under the same slope. （3）The relationship between accumulated sediment and the total runoff was y^-AxB, whose A was defined as the sediment base coefficient, and B was defined as the sediment rate coefficient. （4）The relationship between the erosion sediment increased and sediment concentration was y zax＋b, whose coefficient a reflected the sediment capacity. （~ The runoff increased with increasing rainfall intensity and decreased firstly, then increased, finally decreased with increasing slope. （5） Erosion sediment showed an increased trend with increasing rainfall intensity and changed complex with increasing slope. There was the critical slope between 12° and 15° under the experimental conditions.