Soil water content detection based on acoustic method and improved Brutsaert’s model
2020
Xu, Yan | Li, Jun | Duan, Jieli | Song, Shuaishuai | Jiang, Rui | Yang, Zhou
The traditional Brutsaert’s model does not consider the influence of fixed Poisson’s ratio on the accuracy of the model. Therefore, we extend Brutsaert’s model by introducing Poisson’s ratio dynamic solution model, and obtain the improved Brutsaert’s model which considers the change of soil Poisson’s ratio. The primary objective of this work was to explore whether improved Brutsaert’s model (Poisson’s ratio dynamic solution model is introduced) can more accurately predict soil volumetric water content (SVWC) than traditional Brutsaert’s model. Acoustic velocities (the first compressional wave and shear wave) of natural silica sand (sand) and three different textures of farming soils (loam, sandy loam and clay loam) were measured using pulsed acoustic waves with frequencies less than 900 Hz under the conditions of wet swelling and drying shrinkage, respectively. The traditional Brutsaert’s model and improved Brutsaert’s model are validated by the measured acoustic velocities. We compare the result calculated by improved Brustsaert’s model with that calculcated by traditional Brustsaert’s model. The compared results show that the improved Brustsaert’s model is more suitable for measuring the relationship between the velocity and the soil water content (SWC) than traditional Brustsaert’s model in four different textures of soil samples. In order to verify the feasibility of the improved Brustsaert’s model for predicting soil water content (SWC), field experiments were carried out on three kinds farming soil (loam, sandy loam and clay loam) sampling sites. The results show that the detected precision measured by improved Brustsaert’s model was around 5%.
显示更多 [+] 显示较少 [-]