Numerical modelling of groundwater seepage and landscape evolution along the Canterbury Coast, South Island, New Zealand

Abstract

Groundwater has been implicated as an important geomorphic agent in landscape evolution. The link between groundwater seepage and landscape evolution remains controversial and poorly quantified, however. Groundwater weathering and erosion processes have not been quantified in terms of mechanisms, rates or resulting morphologies. Experimental and numerical analyses of these processes have been based on simplistic assumptions about flow processes and hydraulic characteristics. There is also a paucity of process-based observations and detailed instrumental studies of seepage erosion and weathering due to the long timescales involved and the complexity of the process. Numerical modelling, in particular Landscape Evolution Modelling (LEM), is a valuable tool that can allow us to better understand the spatial and temporal evolution of landscapes by groundwater seepage, particularly when integrated with field data.