模拟降雨条件下黑麦草对土壤水分入渗的影响

利用室内模拟降雨实验的方法,设计了不同降雨强度(30 mm/h和60 mm/h)、不同坡度(10°和20°)和不同草地盖度(0、20%、40%、60%、80%和100%)研究黑麦草影响下土壤水分入渗的变化过程。试验结果表明:坡度、降雨强度和黑麦草盖度对土壤水分的入渗均有影响,土壤水分累积入渗量随黑麦草盖度的增加呈增加趋势,二者显著正相关;黑麦草覆盖下的土壤水分累积入渗量变化过程能够用考斯加科夫模型模拟,黑麦草盖度对模型参数有显著影响。各试验条件下,入渗模型参数K值随黑麦草盖度的增加而增加,α值随黑麦草盖度的增加而减小,二者的变化趋势在降雨强度30 mm/h时表现明显,但在降雨60 mm/h时不明显。

Effects of Ryegrass on Processes of Soil Infiltration Under Simulated Rainfall

Soil and water loss can cause the depletion of land resource and the degradation of eco-environment in many areas of China, which is the main reason of the reduction of local agricultural and industrial productivity. The process of soil infiltration has a major impact on the effect of soil and water conservation. To research how ryegrass influence the effect of soil and water conservation, the experiments in the conditions of different rainfall intensities, slopes and vegetation coverages (0, 20%, 40%, 60%, 80% and 100%) with the method of simulated rainfall were conducted. The results showed that: slope, rainfall intensity and vegetation coverage had a significant impact on the process of soil infiltration, the cumulative amount of water infiltration increased with the increase of vegetation cover, existing a significant positive correlation. The vegetation coverage also had an obvious influence on the model parameters of Kostiakov infiltration model, the parameter K increased but the parameter a decreased with the increase of the vegetation coverage of ryegrass. The change trend was the most notable in 30 mm/h rainfall intensity.