BETCO: Barometric and Earth Tide COrrection

BETCO is a Windows-executable program that removes fluctuations due to barometric pressure and Earth tides in aquifer water-level measurements. BETCO adjusts water-level measurements using barometric and Earth-tide measurements collected at equal intervals by applying a multiple regression (deconvolution) technique.

A Computer Note that describes the regression deconvolution procedure is available at:

  • Toll NJ, Rasmussen TC, 2007, "Removal of barometric pressure effects and Earth tides from observed water levels", Ground Water 45(1):101-105. (download)

Additional articles using this method can be found at:

  • Rasmussen TC, TL Mote, 2007, "Monitoring surface and subsurface water storage using confined aquifer water levels at the Savannah River Site, USA", Vadose Zone Journal 6:327-335. (download)
  • Herkelrath WN, YK Kharaka, JJ Thordsen, MM Abbottt, 2007, "Hydrology and subsurface transport of oil-field brine at the US Geological Survey OSPER site A, Osage County, Oklahoma", Applied Geochemistry 22(10):2155-2163.
  • Stejskal V, L Skalsky, L Kasparek, 2007, "Results of two-years' seismo-hydrological monitoring in the area of the Hronov-Porici Fault Zone, Western Sudetes", ACTA Geodynamica et Geomateriala 4(4):59-76.
  • Halford KJ, 2006, "Documentation of a spreadsheet for time-series analysis and drawdown estimation", USGS Scientific Investigations Report 2006-5024. (download)
  • Spane FA, 2002, "Considering barometric pressure in groundwater flow investigations", Water Resources Research 38(6):1078
  • Desbarats AJ, DR Boyle, M Stapinsky, MJL Robin, 1999, "A dual-porosity model for water level response to atmospheric loading in wells tapping fractured rock aquifers", Water Resources Research 35(5):1495-1505.
  • Rasmussen TC, LA Crawford, 1997, "Identifying and removing barometric pressure effects in confined and unconfined aquifers", Ground Water, 35(3):502-511. (download)

BETCO 1.0 (download), along with the User's Manual (download), are available as free downloads. BETCO was developed by Nathaniel Toll ( and Professor Todd Rasmussen ( at the University of Georgia. Nate developed and currently maintains the program.

Input for the utility is either an ASCII comma-separated-value (CSV) table or Excel spreadsheet of observed water levels, barometric pressures, and synthetic Earth tides in consistent units (either head or pressure) and the measurement time. The output is a matrix of adjusted water-level measurements versus time in either Excel or CSV format.

Synthetic Earth tide gravity can be generated using a variety of free codes available on the internet. We have found TSOFT, developed at the Royal Observatory of Belgium, to be the easiest to use.


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