Mapping the spatial variation of soil moisture at the large scale using GPR for pavement applications

Abstract

The characterization of shallow soil moisture spatial variability at the large scale is a crucial issue in many research studies and fields of application ranging from agriculture and geology to civil and environmental engineering. In this framework, this work contributes to the research in the area of pavement engineering for preventing damages and planning effective management. High spatial variations of subsurface water content can lead to unexpected damage of the load-bearing layers; accordingly, both safety and operability of roads become lower, thereby affecting an increase in expected accidents. A pulsed ground-penetrating radar system with ground-coupled antennas, i.e., 600-MHz and 1600-MHz center frequencies of investigation, was used to collect data in a 16 m × 16 m study site in the Po Valley area in northern Italy. Two ground-penetrating radar techniques were employed to nondestructively retrieve the subsurface moisture spatial profile. The first technique is based on the evaluation of the dielectric permittivity from the attenuation of signal amplitudes. Therefore, dielectrics were converted into moisture values using soil-specific coefficients from Topp's relationship. Ground-penetrating-radar-derived values of soil moisture were then compared with measurements from eight capacitance probes. The second technique is based on the Rayleigh scattering of the signal from the Fresnel theory, wherein the shifts of the peaks of frequency spectra are assumed comprehensive indicators for characterizing the spatial variability of moisture. Both ground-penetrating radar methods have shown great promise for mapping the spatial variability of soil moisture at the large scale

Quantification of Soil Organic Carbon in Biochar-Amended Soil Using Ground Penetrating Radar (GPR)

“…The significant correlations between moisture level and attributes would be important for other research aiming to characterize soil conditions using GPR. Previous researches have already begun to develop tools towards achieving this goal [39,40]. This indicated that if we are to further study soil moisture, multidimensional attribute analysis might be more suitable to display spatial distribution than attribute analysis.…”

Prediction of rutting evolution in flexible pavement life cycle at the road network scale using an air-launched ground-penetrating radar system

“…Amongst the main applications, it is worth citing the evaluation of layer thicknesses [17], the assessment of the damage conditions in Hot-Mix Asphalt (HMA) [18] and load-bearing layers [19], the monitoring of concrete structures [20], and the location of utilities [21]. Important efforts have been also devoted to the evaluation of the volumetric water content within the whole pavement structure [22], [23] and, more recently, to the assessment of clay content in load-bearing layers [24]- [26]. In addition, more recent efforts have been addressed to evaluate the strength and deformation properties of road pavements and materials [27], [28], and towards the GPR-based simulation of pavement faults [29].…”

Soil Water Content Estimation Using High-Frequency Ground Penetrating Radar

“…With too little water, crops can be irreversibly damaged due to drought stress [4]. Consequently, agronomists and farmers need information about shallow SWC variability at both spatial and temporal scales in cultivated regions to manage irrigation practices effectively [5,6]. However, variations in soil texture, topography, geology, tillage, vegetation cover, and irrigation practices result in large spatial and temporal variabilities in shallow SWC [2].…”