Disentangling coastal groundwater level dynamics in a global dataset
Journal article, 2024

Groundwater level (GWL) dynamics result from a complex interplay between groundwater systems and the Earth system. This study aims to identify common hydrogeological patterns and to gain a deeper understanding of the underlying similarities and their link to physiographic, climatic, and anthropogenic controls of groundwater in coastal regions. The most striking aspects of GWL dynamics and their controls were identified through a combination of statistical metrics, calculated from about 8000 groundwater hydrographs, pattern recognition using clustering algorithms, classification using random forest, and SHapley Additive exPlanations (SHAPs). Hydrogeological similarity was defined by four clusters representing distinct patterns of GWL dynamics. These clusters can be observed globally across different continents and climate zones but simultaneously vary regionally and locally, suggesting a complicated interplay of controlling factors. The main controls differentiating GWL dynamics were identified, but we also provide evidence for the currently limited ability to explain GWL dynamics on large spatial scales, which we attribute mainly to uncertainties in the explanatory data. Finally, this study provides guidance for systematic and holistic groundwater monitoring and modeling and motivates a consideration of the different aspects of GWL dynamics, for example, when predicting climate-induced GWL changes, and the use of explainable machine learning techniques to deal with GWL complexity – especially when information on potential controls is limited or needs to be verified.

Author

Annika Nolte

Climate Service Center Germany (GERICS), Helmholtz-Zentrum Hereon

Ezra Haaf

Chalmers, Architecture and Civil Engineering, Geology and Geotechnics

Benedikt Heudorfer

Karlsruhe Institute of Technology (KIT)

S. Bender

Climate Service Center Germany (GERICS), Helmholtz-Zentrum Hereon

Jens Hartmann

University of Hamburg

Hydrology and Earth System Sciences

1027-5606 (ISSN) 16077938 (eISSN)

Vol. 28 1215-1249 28-1215-2024

Driving Forces

Sustainable development

Subject Categories

Geotechnical Engineering

Oceanography, Hydrology, Water Resources

Computer Science

DOI

10.5194/hess-28-1215-2024

More information

Latest update

4/16/2024