Abstract
In recent years, various models have been developed to describe Arctic
coastal erosion. Many models are process-based, simulating multiple
physical processes and combining them interactively to resemble Arctic
coastal erosion. One limitation of the current process-based models is
the difficulties in including the hydrodynamic forces. The morphological
changes by the hydrodynamics are either simplified or simulated by some
empirical relation. The reason for excluding detailed hydrodynamic
forcing is the absence of thermal energy conservation in the systems of
equations inside the available software. Most hydrodynamic models are
designed considering the warmer climate, where waves, tides and storm
surges cause changes in morphology. The available models cannot be
applied where permafrost is a significant environmental parameter. This
paper explains a methodology that allows us to use the models designed
for warmer climates to simulate Arctic coastal erosion. The open-source
software XBeach is used to simulate the waves, sediment transport and
morphological changes. We developed different submodules for the
processes related to permafrost thawing-freezing, slumping, wave-cut
niche, bluff failure, etc. The submodules are coupled with the XBeach
following a workflow where ice concentration, storm surge and bluff
collapse work as an on-off switch. The submodules communicate with each
other at three-hour intervals. The input parameters of the model are
calibrated with field measurements. The model is then validated by
another set of mutually exclusive field measurements under different
geological conditions. The model can simulate the short term (one year)
and long term (a few years) with the same level of fidelity.