Experimental study on unsaturated soil water diffusivity in different soils in Hebei Piedmont Plain

• 作者: FENG Xin GAO Ye-xin LIU Ji-chao ZHANG Bing ZHANG Ying-ping
• 来源期刊: 地下水科学与工程:英文版
• 学科: 工学
• 关键词: Hebei PIEDMONT plain Soil WATER DIFFUSIVITY BOLTZMANN parameter VOLUMETRIC WATER content
• 年，卷（期）: dxskxygcywb,（2）
• 页码范围: 165-172
• 页数: 8页
• 分类号: TV

摘要

Horizontal soil column method was used to determine the horizontal diffusion rate of sandy loam, loam and clay loam under the same bulk density. The results showed that the migration rates of different lithological wet fronts were different. The sandy loam had the fastest migration rate, the loam followed, and the clay loam was the slowest, but the law of change is the same among the three lithologies. The volumetric water content affects the change of Boltzmann parameter λ. When the volumetric water content is between 0.35-0.45 cm^3/cm^3,λ approaches stability. When the volumetric water content is less than 0.35 cm^3/cm^3, the λ value decreases rapidly with the decrease of water content. The water diffusion rate is related to the volumetric water content and particle size. The greater the moisture content is, the greater the diffusion rate will be. The larger the particle size, the larger the diffusion rate. The diffusivity of sandy loam is 10-30 times larger than that of loam and clay loam. The relationship between water content and diffusion rate is in accordance with the exponential function .