Effects of homogeneous/heterogeneous water distribution on GPR wave velocity in a soil's wetting and drying process

J. F.C. Sham, Wai Lok Lai, C. H.C. Leung

Research output: Chapter in book / Conference proceedingConference article published in proceeding or bookAcademic researchpeer-review

5 Citations (Scopus)


This paper studies the effects of relatively homogeneous (RHWD) and relatively inhomogeneous water distributions (RIWD) in soil compared by varying the water content through a wetting and drying cycle in a tank (1.85m long × 1.55m wide × 1m deep) filled with 750mm thick plant soil. During the cycle, a 900MHz antenna was regularly used to capture GPR radargrams on a buried steel pipe. Hyperbolic reflections of a buried pipe at a fixed position were extracted to measure wave velocities/dielectric constants at different RHWD and RIWD in the wetting and drying cycle. A vertical coaxial-based water content sensor was also installed in a vertical standpipe in the middle of the tank to obtain the vertical water content profile, synchronized with and correlated to the GPR wave velocity/dielectric constant of the soil. The result of cross plotting between the dielectric constant and soil water content shows that the volumetric fraction of water in a porous medium is the sole important factor affecting dielectric properties of soil.
Original languageEnglish
Title of host publicationProceedings of 2016 16th International Conference of Ground Penetrating Radar, GPR 2016
Number of pages5
ISBN (Electronic)9781509051816
Publication statusPublished - 20 Sep 2016
Event16th International Conference of Ground Penetrating Radar, GPR 2016 - Hong Kong Polytechnic University, Hong Kong, Hong Kong
Duration: 13 Jun 201616 Jun 2016


Conference16th International Conference of Ground Penetrating Radar, GPR 2016
Country/TerritoryHong Kong
CityHong Kong


  • GPR wave velocity
  • Relatively heterogeneous water distribution (RIWD)
  • Relatively homogeneous water distributions (RHWD)
  • Soil permittivity

ASJC Scopus subject areas

  • Signal Processing
  • Instrumentation

Cite this