An Examination of Soil Moisture Estimation Using Ground Penetrating Radar in Desert Steppe

Abstract

Ground penetrating radar (GPR) is a new technique of rapid soil moisture measurement, which is an important approach to measure soil moisture at the intermediate scale. To test the applicability of GPR method for soil moisture in desert steppe, we used the common-mid point (CMP) method and fixed offset (FO) method to evaluate the influence factors and the accuracy of GPR measurement with gravimetric soil moisture measurements. The experiments showed that Topp's equation is more suitable than Roth's equation for processing the GPR data in desert steppe and the soil moisture measurements by GPR had high accuracy by either CMP method or FO method. To a certain extent, the vegetation coverage affects the measurement precision and the soil moisture profile. The precipitation can reduce the effective sampling depth of the ground wave from 0.1 m to 0.05 m. The results revealed that GPR has the advantages of high measurement accuracy, easy movement, simple operation, and no damage to the soil layer structure.

A Review on Applications of Remote Sensing and Geographic Information Systems (GIS) in Water Resources and Flood Risk Management

“…Water resources mapping and management Glaciers mapping Landsat, ASTER GDEM, GIS, TIN 3D model. [36] Soil moisture detection GPR, CMP, FO, GIS spatial analysis [16] Groundwater and subsidence analysis GIS spatial analysis, GPS [37] Irrigation planning UAV, HTM for video image classification, GIS visualization [32] Rainfall measurements and design storm…”

“…The common soil moisture measurement technologies, such as the gravimetric method, neutron method, Time Domain Reflector (TDR), Frequency Domain Reflectometry (FDR), and so on, provide point measurements with high accuracy, while being labor and time-consuming and may destroy the soil structures. Lu et al [16] in this special issue present their study to measure the steppe soil moisture using Ground Penetrating Radar (GPR). The common-mid point (CMP) method and fixed offset (FO) method are used for sensitivity analysis, while the gravimetric soil moisture measurements are used to validate the accuracy of the GPR measurements.…”

“…Groundwater is the most difficult to detect by satellite sensors, while the Gravity Recovery and Climate Experiment (GRACE) has been successfully used to measure groundwater depletion and the filling of the Three Gorges Reservoir [14,15]. Ground penetration radar can even obtain accurate estimations of glacier thickness, soil moisture, and groundwater [16,17].…”

Soil Water Content Estimation Using High-Frequency Ground Penetrating Radar

“…The content of clay also has a large influence on the soil dielectric permittivity, which increases with the soil clay content. As the clay content increased, both the real and imaginary parts of the relative soil permittivity increased [23,26]. The reasons for the low soil dielectric permittivity at high soil clay contents are the high volume expansion, high moisture absorption capacity, and high electrical conductivity, which result in high dielectric losses.…”

“…Recently, ground penetrating radar (GPR) has been widely used to determine SWC at the field scale because it does not directly measure SWC; rather, it is a common practice to use fitted curves that describe the relationship between SWC and the soil dielectric permittivity [4,12]. The GPR method is rapid and continuous and provides in situ measurements of underground media; consequently, it has been applied in a variety of disciplines, such as hydrology, hydrogeology, archaeology, glacier and frozen soil research, soil science, and environmental science [5,18,[23][24][25][26]. For example, according to [4] and [27], authors reviewed four methods to measure SWC with GPR and suggested that high-frequency electromagnetic techniques are the most promising methods for measuring SWC.…”