不同粒径黄绵土的溅蚀规律及表土结皮发育研究

RAIN SPLASH EROSION AND SOIL CRUST DEVELOPMENT OF LOESS SOILS DIFFERENT IN PARTICLE-SIZE

溅蚀是土壤侵蚀过程的开始,为侵蚀发展提供了物质来源。因此,对其进行研究有助于对侵蚀过程的深入了解。本文选择了广泛分布于黄土高原地区的黄绵土,通过对不同粒径的土样进行模拟降雨试验,分析了土壤颗粒的溅蚀规律和表土结皮的形成过程,以及溅蚀率变化趋势。结果表明,不同粒径土样的溅蚀量差异明显,粒径在0.15mm附近的土壤颗粒最易被溅蚀;在一定的降雨历时内不同粒径土样的表土结皮发育完善程度不同,据此可以很好地解释溅蚀率的变化。

When raindrops hit the soil, they trigger rain splash and formation of soll crust. Researchers used to pay attention to interactions of them. However, the relationships between the two varying with particle-size of the soil have seldom been reported. Under simulated rainfalls in laboratory, splash erosion and soil crust development of Loess soils different in particle-size are observed and analyzed. Results show that distinct differences exist in amount of rain splash between soil samples. Soil samples about 0.15 mm in particle-size are the most susceptible to rain splash. Within a given duration of rainfall, the development of soil crust also varies with particle-size of the soil, which explains variation of splash rate.