Ground Penetrating Radar (GPR) Analysis of Soil Moisture Within Different Landuses in an Agriculture Landscape, in Georgia, US

Abstract

Soil moisture is a critical process in the water cycle and its assessment is of paramount importance to forecast changes in the water balance of a region. Ground Penetrating Radar (GPR) technology overcomes the limitations of point data by producing a tri-dimensional view of subsurface characteristics with a large economy of time, logistic, data processing and analysis. The purpose of this research is to study soil moisture under different land use/land covers (LULC) at the Little river watershed, near Tifton, Georgia collecting point data using a hand carried Theta probe (TP), and tri-dimensional data using a GPR equipment. Two sampling sites and six different land uses were analyzed in this project taking simultaneous samples with both instruments. Sub-surface tri-dimensional maps of 30x30m fields 1m depth were collected in three fields under different land use and vegetation cover. Transects of 30m and 1m depth were collected, one per field, for three additional fields under different land use and vegetation cover. Visualization tools and statistical analysis are used to compare subsurface profiles and soil moisture within and among land uses. Preliminary results showed that sub-surface soil in agriculture fields is highly stratified in patterns that can be the result of disturbance caused by agriculture equipment and practices and that affect the homogeneous distribution of soil moisture. These results are important to show a predominant role of ground disturbance in the soil moisture behavior.