lhalloran / Gravi4GW

A tool for conversion between Δg and groundwater storage changes. https://doi.org/10.1016/j.envsoft.2022.105340

Gravi4GW

Landon Halloran (www.ljsh.ca) 2021

What it is and what it does.

Gravi4GW (pronounced Gra-vee-for-ground-wa-ter) is a python tool that enables the calculation of the conversion factor between changes in gravity (Δg) as measured using time-lapse gravimetry and changes in groundwater storage (GWSC). The tool calculates β (or rather, β_z), the rate of change in gravity as groundwater storage changes (dg/dh) in units of μGal/m_H2O (=1 x 10^-8 s^-2). A very similar quantity, wherein the effective depth to the groundwater table is set to 0, is also known as "topographical admittance.".

Basic intended uses are:

• Conversion of measured Δg data to GWSC in terms of equivalent free water column height in meters.
• Creation of maps of β to target gravimetric field work.
• Uncertainty analysis in hydrogeological time-lapse gravimetry studies.

How to cite.

Halloran, L.J.S. (2022). "Improving groundwater storage change estimates using time-lapse gravimetry with Gravi4GW", Environmental Modelling and Software 150, 105340. https://doi.org/10.1016/j.envsoft.2022.105340

Please contact me for more info.

How to use.

For a simple demonstration of usage, see demo.py.

Basic usage:

import Gravi4GW
# ...
# User defines GEOTIFF_path, stn_x, stn_y, h_eff ...
# ...
output = Gravi4GW.Gravi4GW(GEOTIFF_path, stn_x, stn_y, h_eff)

More information on the inputs and outputs of the functions contained in Gravi4GW.py can be obtained by typing, for example, help(Gravi4GW.Gravi4GW).