淮北平原黄潮土多雨强变坡度产流产沙规律试验模拟

Simulation of Runoff and Sediment Production Regularity of Different Rainfall Intensity and Changeable Slope Gradients in the Yellow Fluvo-aquic Soil of the Huaibei Plain

针对淮北平原黄潮土水土流失严重的问题,为揭示其产流产沙规律,利用五道沟水文实验站大型人工模拟降雨径流试验场,开展了40,60,80mm/h 3个雨强及5°,10°,15°3个坡度产流产沙规律试验模拟。结果表明:坡面初始产流时间随坡度、雨强的增大而缩短,雨强、坡度越大缩短越不明显;单位时间产流、产沙量随降雨时间变化的转折点在产流后6～15min,单位时间产流量随降雨时间变化表现为前期快速增加,中期缓慢增加,后期平稳,其中40,60mm/h雨强单位时间产流量随坡度增加而减小,80mm/h雨强随坡度的增加而增加;单位时间产沙量随雨强、坡度的增大而增大;不同坡度累计产沙量及产流量随降雨时间变化呈幂函数或线性函数关系(R2>0.99);坡度及雨强与坡面产流、产沙总量分别呈多元线性和多元幂函数关系。

Aiming at the serious problem of water and soil loss of the yellow fluvo-aquic soil in the Huaibei Plain,in order to reveal the law of runoff and sediment yield,the large artificial simulated rainfall runoff test field of Wudaogou Hydrological Experimental Station was used to carry out three rain intensity of40,60,80mm/h and threeslope gradients of5°,10°,15°runoff and sediment production simulation.The results showed that the initial runoff time of the slope is shortened with the increase of slope and rain intensity.It is less obvious with the increase of rain intensity and slope.The turning point of the runoff and sediment yield per unit time with the change of rainfall time is6~15min after the runoff.The change of production flow per unit time with the change of rainfall time showed a rapid increase in the early stage,a slow increase in the medium term,and a stable period in the later period.The40,60mm/h rain intensity per unit time flow rate decreased with the increase of the slope,however,the rain intensity increased with the increase of slope with80mm/h.The sediment yield per unit time increased with the increase of rain intensity and slope.The cumulative sediment yield and yield of different slopes showed a power or linear function with the change of rainfall time(R2>0.99).The effects of slope and rainfall intensity on runoff and total sediment yield were multivariate linear and multivariate power functionsrelationship.