Authors: Chameera Illawathure, Lakshman Galagedara, Mumtaz Cheema, Adrian Unc, Vanessa Kavanagh
Published in: CSBE-SCGAB Technical Conferences » 5th CIGR and AGM Quebec City 2021 » Regular Sessions
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Description: Due to the high correlation between dielectric permittivity and soil water content, ground penetrating radar (GPR) gives strong reflections from the top of the saturated soil boundary. The prominent and early reflection could come from the capillary fringe, followed by the reflection from the actual water table. The objectives of this study were to calibrate and validate a site-specific relationship between GPR-estimated depth to the capillary fringe (DCF) and measured-WTD data, and to estimate the average capillary height. GPR surveys were carried out along 30-42 m long transect using 100 and 250 MHz center frequency antennas of PulseEKKO Pro GPR system. Water table depth and soil moisture at 10, 20 and 30 cm were recorded next to the GPR transect. The average radar velocity from the surface down to the top of the capillary fringe was calculated based on GPR wave propagation geometry using GPR groundwave analysis, soil moisture measurement and published data. A strong linear relationship (R2 = 0.9778) between DCF and WTDm was developed (WTDm = 0.6956 DCF + 1.3884) for the experimental site in 2017. The regression model was validated in the same location in 2018. Similarly, another regression model was developed using all GPR data collected for two growing seasons and an average capillary height of 0.741 m (R2 =0.911, n=16) was suggested throughout the growing season. The developed model is recommended to modify using multiple data collected representing different growing seasons covering a wider variability of the water table and soil moisture.
Conference name: 5th CIGR International Conference and CSBE-SCGAB AGM 2021, Quebec City,QC, 11-14 May 2021.
Session name: Soil and Water 2 - Soils Topics
Publication type: Presentation
Language 1: en
Rights: Canadian Society for Bioengineering