土壤含水量对探地雷达探测植物根系构型精度的影响

Root biomass is an important part of the soil ecosystem, however, due to the limitations of measurement techniques and methods, it is impossible to rapidly assess it. The ground penetrating radar (GPR) is an efficient and nondestructive geophysical tool through which root information can be obtained without damaging the soil environment. However, accuracy during the detection and identification of underground roots by GPR is significantly affected by many factors such as soil water content, root roughness, length, and extension direction. In particular, soil water content has an obvious effect on root detection. In this study, in situ root embedding detection experiments were carried out to investigate the influence of soil water content on root detection via GPR. Combined with the changes in wave velocity, amplitude, and the root reflection coefficient of the GPR, the root point identification rate and root point distance root point root mean square error were analyzed under different average soil water content. The results showed that (1) the wave velocity and amplitude of the GPR were important parameters to determine variations in soil water conten during root detection; (2) the GPRs velocity decreased and the radar amplitude flattened with the increasing soil water content; (3) as the root diameter increased at different soil depths, the GPRs wave velocity also increased and the GPRs amplitude tended to be drastic changes; (4) the root point recognition rate and soil water content were negatively correlated (P