Abstract
The determination of quantitative relationship between soil dielectric constant and water content is an important basis for measuring soil water content based on ground penetrating radar (GPR) technology. The calculation of soil volumetric water content using GPR technology is usually based on the classic Topp formula. However, there are large errors between measured values and calculated values when using the formula, and it cannot be flexibly applied to different media. To solve these problems, first, a combination of GPR and shallow drilling is used to calibrate the wave velocity to obtain an accurate dielectric constant. Then, combined with experimental moisture content, the intelligent group algorithm is applied to accurately build mathematical models of the relative dielectric constant and volumetric water content, and the Topp formula is revised for sand and clay media. Compared with the classic Topp formula, the average error rate of sand is decreased by nearly 15.8%, the average error rate of clay is decreased by 31.75%. The calculation accuracy of the formula has been greatly improved. It proves that the revised model is accurate, and at the same time, it proves the rationality of the method of using GPR wave velocity calibration method to accurately calculate the volumetric water content.
Highlights
In the Shenmu area of northern Shaanxi, China
Based on experimental moisture content and relative dielectric constant which was calculated from accurate wave velocity
Particle swarm optimization algorithm and simulated annealing algorithm constant optimization results are shown in Figures 9 and 10
Summary
In the Shenmu area of northern Shaanxi, China. There are a wide range of sand and clay layers which contain precious water resources that play an important role in the growth of surface vegetation. As one of the largest coal reserves in China, the northern Shaanxi coalfield has been widely concerned at both domestic and abroad because of its advantages like thick coal seam, good coal quality and etc. The vigorous underground coal mining activities will inevitably affect the shallow soil and change the water resources contained in the shallow soil (Wei, 2009). The determination of the water content within a certain depth of the ground is of great significance for studying the trend of water resources in this area, and it is very important for guiding the protection of the local ecological environment
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
