Palaeochannels as hidden pathways of water flow in agricultural alluvial landscapes: a review of concepts and suggested future directions for modelling

Sustaining agricultural productivity while reducing off-site impacts on water quality requires a detailed understanding of water and nutrient movement through alluvial landscapes. Within these settings, palaeochannels − old river courses infilled with coarse sediments − represent major but poorly quantified subsurface flow pathways. Their influence on water and solute transport is rarely incorporated into hydrological assessments or models, despite their widespread occurrence and hydraulic connectivity with surface drains, aquifers and streams. This paper reviews current knowledge of palaeochannel structure, distribution and hydrologic function within agricultural alluvial systems, and evaluates approaches for their identification, characterisation and representation in hydrologic models. We examine the suitability of existing coupled modelling frameworks − such as HYDRUS-MODFLOW, SWAT-MODFLOW, MIKE-SHE and HydroGeoSphere − for simulating palaeochannel-mediated flow and material transport. Conceptual similarities between palaeochannels and engineered tile-drain networks are used to illustrate how established drainage formulations can inform future model development.

Journal of Hydrology

Journal of Hydrology

674

0022-1694

N/A

N/A

14