From ice to water using landscape evolution models
Modelling the effects of mountain deglaciation on proglacial runoff and channel patterns
T. de Kok (TU Delft - Civil Engineering & Geosciences)
Remi Charton – Mentor (TU Delft - Applied Geology)
Kieran Dunne – Mentor (TU Delft - Rivers, Ports, Waterways and Dredging Engineering)
M. Rebolledo Gaínza – Mentor (TU Delft - Applied Geology)
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Abstract
This research examined the influence of low- to mid-latitude mountain deglaciation on the channel pattern of proglacial rivers and evaluated the suitability of the Badlands Landscape Evolution Model to simulate glacial thinning, retreat, and runoff. Glacier types and scenarios were constructed based on size, mass turnover, and climate projections. Seasonal precipitation maps were derived from runoff projections to represent meltwater production and rainfall and inputted into Badlands. Glacier thinning was modelled using a modified stream power law, enforcing a linear dependence of erosion on precipitation. Modelled proglacial discharge was used to determine the dominant channel pattern. The results show that annual glacial runoff will slightly increase in the short term, leading to a minor and largely insignificant increase in river braiding. Over time, runoff will decline to slightly below initial levels, resulting in a similarly insignificant reduction in braiding. Seasonal patterns will shift, with runoff decreasing in summer and autumn and increasing in winter and spring due to rainfall replacing snowfall. Runoff was found to be strongly dependent on glacier size, moderately dependent on mass
turnover, and only marginally affected by climate scenario. The fluvial pattern was found to be braided in almost all cases. Only low mass turnover glaciers in arid climates may experience minor downstream changes in channel pattern, depending on the extent of current glaciation. At present, Badlands is unable to model glacier dynamics efficiently due to computational limitations and the lack of mass balance, glacial erosion, and sliding laws. Furthermore, it only models glacial thinning and does not directly convert ice mass loss into runoff. Nevertheless, the model provides a strong foundation for implementing glacial features such as elevation-dependent melting and ice-to-runoff conversion.