GMD perspective: The quest to improve the evaluation of groundwater representation in continental- to global-scale models

Continental- to global-scale hydrologic and land surface models increasingly include representations of the groundwater system. Such large-scale models are essential for examining, communicating, and understanding the dynamic interactions between the Earth system above and below the land surface as...

Full description

Saved in:
Bibliographic Details
Published in:Geoscientific Model Development 2021-12, Vol.14 (12), p.7545-7571
Main Authors: Gleeson, Tom, Wagener, Thorsten, Döll, Petra, Zipper, Samuel C, West, Charles, Wada, Yoshihide, Taylor, Richard, Scanlon, Bridget, Rosolem, Rafael, Rahman, Shams, Oshinlaja, Nurudeen, Maxwell, Reed, Lo, Min-Hui, Kim, Hyungjun, Hill, Mary, Hartmann, Andreas, Fogg, Graham, Famiglietti, James S, Ducharne, Agnès, de Graaf, Inge, Cuthbert, Mark, Condon, Laura, Bresciani, Etienne, Bierkens, Marc F. P
Format: Article
Language:English
Subjects:
Aquifers
Atmosphere
Atmospheric boundary layer
Communication
Earth Sciences
Evaluation
Groundwater
Groundwater availability
Groundwater levels
Groundwater models
Groundwater recharge
Groundwater resources
Hydrogeology
Hydrologic cycle
Hydrologic models
Hydrologists
Hydrology
Land surface models
Large-scale models
Learning algorithms
Learning behaviour
Machine learning
Modelling
Observational learning
Regional development
Regional-scale models
Regions
Representations
Scale models
Sciences of the Universe
Sea level
Stream flow
Sustainability
Water resources
Water, Underground
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Continental- to global-scale hydrologic and land surface models increasingly include representations of the groundwater system. Such large-scale models are essential for examining, communicating, and understanding the dynamic interactions between the Earth system above and below the land surface as well as the opportunities and limits of groundwater resources. We argue that both large-scale and regional-scale groundwater models have utility, strengths, and limitations, so continued modeling at both scales is essential and mutually beneficial. A crucial quest is how to evaluate the realism, capabilities, and performance of large-scale groundwater models given their modeling purpose of addressing large-scale science or sustainability questions as well as limitations in data availability and commensurability. Evaluation should identify if, when, or where large-scale models achieve their purpose or where opportunities for improvements exist so that such models better achieve their purpose. We suggest that reproducing the spatiotemporal details of regional-scale models and matching local data are not relevant goals. Instead, it is important to decide on reasonable model expectations regarding when a large-scale model is performing “well enough” in the context of its specific purpose. The decision of reasonable expectations is necessarily subjective even if the evaluation criteria are quantitative. Our objective is to provide recommendations for improving the evaluation of groundwater representation in continental- to global-scale models. We describe current modeling strategies and evaluation practices, and we subsequently discuss the value of three evaluation strategies: (1) comparing model outputs with available observations of groundwater levels or other state or flux variables (observation-based evaluation), (2) comparing several models with each other with or without reference to actual observations (model-based evaluation), and (3) comparing model behavior with expert expectations of hydrologic behaviors in particular regions or at particular times (expert-based evaluation). Based on evolving practices in model evaluation as well as innovations in observations, machine learning, and expert elicitation, we argue that combining observation-, model-, and expert-based model evaluation approaches, while accounting for commensurability issues, may significantly improve the realism of groundwater representation in large-scale models, thus advancing our ability fo
ISSN:1991-9603
1991-959X
1991-962X
1991-9603
1991-962X
1991-959X
DOI:10.5194/gmd-14-7545-2021