Lumped geohydrological modelling for long-term predictions of groundwater storage and depletion

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

Abstract

Excessive groundwater pumping exacerbates aquifer depletion and poses a major threat in regions all around the world that already suffer from overuse or climate change. In this situation, accurate and reliable predictions of long-term aquifer water balances are key prerequisites to manage groundwater sustainably. Compared to spatially explicit numerical models, lumped hydrological models are computationally fast, lean on data requirement and more accessable for quantifying uncertainty. However, lumped hydrological models are mainly designed to simulate river discharge only, not aquifer storage. Consequently, calibration only includes stream flow data. In this study, we hypothesize that we can extend a lumped hydrological models (here HBV) towards a lumped geohydrological model (LGhM) by additional, designated terms for water budget and groundwater storage. The model building is inspired by the geometry and hydrogeological large-scale properties of the catchment's aquifers. Underground flow routing resembles major groundwater flow paths. The model is calibrated and evaluated on both groundwater storage data and surface discharge data. We apply our LGhM to a MODFLOW-based virtual reality describing the unconfined Wairau Plain Aquifer, New Zealand. We consider and discuss specifically river-groundwater exchange processes, long-term forecast of aquifer storage dynamics, and groundwater depletion in a hypothetical, persistent drought. Our model evaluation shows very plausible predictive capabilities in 40-year forecasts with synthetic weather time series and several years of groundwater depletion in the extreme drought case.

Details

Original languageEnglish
Article number127347
JournalJournal of hydrology
Volume606
Early online date31 Dec 2021
Publication statusPublished - Mar 2022
Peer-reviewedYes

External IDs

Scopus 85123050495
Mendeley d04958e1-bc36-39c9-be4d-879cb48c2e74
unpaywall 10.1016/j.jhydrol.2021.127347
ORCID /0000-0003-2963-0965/work/155291958

Keywords

Sustainable Development Goals

ASJC Scopus subject areas

Keywords

  • Water management, long-term water balance, conceptual groundwater model, Long-term water balance, Conceptual groundwater model