Study On Fast Determination Of Water, Oil And Salt Content In Soil Using GPR

The study of the temporal and spatial distribution characteristics of soil contaminated area based on the reflected wave variation of ground-penetrating radar (GPR) detection profile has made great progress and obtained good results in practical application. However, the study of soil pollution degree evaluation based on the detection profile of ground-penetrating radar has just started and made slow progress. In this paper, the dielectric constant has been tried to get from the GPR profile and the relationship between the dielectric constant and content of pollutants in soil has been established, in this way it can realize quantitative evaluation of soil pollution levels according to the results of GPR detection profile.This paper studies mainly ground penetrating radar image feature of laboratory simulation experiments of non-contaminated soil, organic pollution soil and inorganic pollution soil; characteristics of ground-penetrating radar images of different soil moisture in situ simulation experiments; the method to get the dielectric constant from ground penetrating radar profile; establishment of quantitative relationship between the dielectric constant and different pollutants content. Some progress was obtained in the following aspects: It is simple to get the dielectric constant according to formula . Velocity acquisition in the formula may be determined in situ direct wave test or velocity analysis method, but calibration of the sampling method is more accurate;The dielectric constant based on the detection profile can reflect changes by the soil composition and content caused and it can be used to quantify pollution levels of the soil;Relationship between the pore water content and the radar dielectric constant follows the Alharathi formula; therefore soil moisture can be quantified. The dielectric property of organic compounds (oil) contaminated soil is in line with the diffused dielectric model. But experiments show that the CRIM mode can be used to quantify the oil content in the soil.Research shows that the neural network can be used for quantitative analysis of inorganic pollution soil while the dielectric constant and amplitude acts as input parameters.This paper has established the quantitative methods to use ground-penetrating radar technology for the evaluation of soil pollution levels, and established quantitative analysis formula between the soil dielectric constant and the pollutant concentration; it laid the wider application foundation in using ground-penetrating radar geophysical exploration methods to evaluate soil pollution.The extensive and in-depth study will begin in the next work on the dielectric constant impact of different soil pollutants, and this study will establish quantitative relationship between the pollution levels and the dielectric constant of soil types, physical and mechanical condition, pollutants types.