Soil profile stratigraphy detected by ground penetrating radar in the
modern Yellow River Delta
Abstract
Soil profile stratigraphy plays a fundamental role in the vertical
movement of soil water and salt, land cover and land use pattern change
in the modern Yellow River Delta. We investigated 22 typical soil
profiles with ground penetrating radar (GPR) of 250 MHz antenna
according to the tail wing changes over the past 130 years, calculated
soil dielectric permittivity and electromagnetic wave propagation
velocity with measured soil water content, acquired the electromagnetic
wave propagation time from the amplitude-time matrix and finally
calculated the thickness of different soil layers. The results showed
that GPR can identify the 0-1m soil profile stratigraphy, and soil
cultivation layer under different land use patterns is clearly
discernible. The comparison of GPR spectrum image and amplitude-time
plot is helpful to reduce the estimation error of soil layer thickness.
The average error of the estimated soil layer thickness is 0.040m and
the error of 54 soil layers in total 58 soil layers is less than 0.100m.
The comprehensive effect of soil physical and chemical characteristics
affects the electromagnetic wave signals and the profile stratigraphy
identification. The more similar the morphological characteristics of
spectral images are, the closer the soil properties are. The compound
effect of soil water and salt is strong, and the second derivative
values of envelop amplitude energy have negative logarithmic function
and power function with soil water content and electrical conductivity
values, respectively. This study indicated the feasibility of using GPR
to investigate coastal saline soil stratigraphy in the modern Yellow
River Delta.