Joint Estimation of Gross Recharge, Groundwater Usage, and Hydraulic Properties within HydroSight

• Published in: Ground water 2019-11, Vol.57 (6), p.860-876
• Main Authors: Peterson, Tim J., Fulton, Simon
• Format: Article
• Language: English
• Subjects: Aquifers; Australia; Biological evolution; Calibration; Drawdown; Estimates; Estimation; Evapotranspiration; Groundwater; Groundwater management; Groundwater recharge; Hydraulic properties; Hydraulics; Parameter estimation; Properties; Properties (attributes); Reproducibility of Results; Transmissivity
• ISSN: 0017-467X; 1745-6584
• DOI: 10.1111/gwat.12946

Groundwater management decisions are often founded upon estimates of aquifer hydraulic properties, recharge and the rate of groundwater usage. Too often hydraulic properties are unavailable, recharge estimates are very uncertain, and usage is unmetered or infrequently metered over only recent years or estimated using numerical groundwater models decoupled from the drivers of drawdown. This paper extends the HydroSight groundwater time‐series package ( http://peterson‐tim‐j.github.io/HydroSight/) to allow the joint estimation of gross recharge, transmissivity, storativity, and daily usage at multiple production bores. A genetic evolutionary scheme was extended from estimating time‐series model parameters to also estimating time series of usage that honor metered volumes at each production bore and produces (1) the best fit with the observed hydrograph and (2) plausible estimates of actual evapotranspiration and hence recharge. The reliability of the approach was rigorously tested. Repeated calibration of models for four bores produced estimates of transmissivity, storativity, and mean recharge that varied by a factor of 0.22‐0.32, 0.13‐0.2, and 0.03‐0.48, respectively, when recharge boundary effects were low and the error in monthly, quarterly, and biannual metered usage was generally