鄂东南花岗岩红壤不同土层侵蚀过程

为了探讨不同降雨动能条件下花岗岩红壤各层次(淋溶层、淀积层、母质层)在坡面侵蚀过程中的产流产沙特征,研究采用室内人工模拟降雨试验方法,对其水动力学参数变化特征及其与土壤侵蚀速率之间的定量关系进行了研究。结果表明:(1)降雨动能对各层次土壤坡面的产沙产流特征影响显著。随着降雨动能增加,各层次土壤初始产流时间不断递减,且径流含沙量和总产沙量均不断增大;(2)各层次土壤之间的侵蚀规律差异显著。初始产流时间、径流含沙量及总产沙量均表现出显著差异; 通过回归分析,发现土壤侵蚀速率与降雨动能之间有良好的线性关系;(3)水流功率和单位水流功率与土壤侵蚀速率均呈显著的相关性,且能够用幂函数准确地描述它们之间的关系,引入土壤黏粒含量可使得模型更加可靠,在实际应用中有更广的应用范围和现实价值。综上,降雨动能和土壤质地对花岗岩红壤坡面侵蚀的形成和发展过程具有显著影响。

Experimental Study on Erosion Process Among Different Soil Layers of Granite Red Soil in Southeast Hubei Province

Through indoor artificial rainfall simulated experiments, we preliminarily explored the characteristics of runoff and sediment yield, the changes in hydrodynamic parameters and their quantitative relationships with soil erosion rate during the slope erosion process of the various layers of the granite red soil(eluvial layer, sediment layer, parent layer)under different rainfall kinetic energy conditions. The results show that:(1)rainfall kinetic energy had a significant impact on the sediment and runoff characteristics of different soil layers; with the increase of rainfall kinetic energy, the initial runoff time of each layer of soil continued to decrease, and the runoff sediment content and total sediment yield continued to increase;(2)there were significant differences in the erosion processes between the soil layers; the initial runoff time, runoff sediment content and total sediment yield all showed significant differences; Iit was found that there was a good linear relationship between soil erosion rate and rainfall kinetic energy through regression analysis;(3)stream power and unit stream power had a significant correlation with soil erosion rates, and the relationship between them could be accurately described by a power function; the introduction of soil clay content could make the model more reliable and have a wider range of applications and higher practical value in practical applications. In conclusion, rainfall kinetic energy and soil texture had significant effects on the formation and development of granite red soil slope erosion.