Sediment transport refers to the displacement of granular materials, such as sand and gravel, under the combined action of gravity and fluid flow. This study presents an open-source numerical model developed to investigate this process, with particular emphasis on the migration of an isolated dune. Beyond this specific application, the model has broad potential, including the analysis of erosion around engineered structures, ripple formation, and the morphological evolution of river systems.

Groundwater plays a key role in land–atmosphere water and energy exchange, yet it is often simplified in large-scale Earth system models. We review 20 years of efforts to couple the groundwater model ParFlow with land surface and atmospheric models, showing how groundwater dynamics shape terrestrial fluxes. We also present an updated coupling framework that enhances model performance and flexibility, and outline a modular strategy to guide future development.