Ice-Wedge Polygon Type Controls Low-Gradient Watershed-Scale Hydrology

Ice-wedge polygons and related microtopographic variations are ubiquitous to landscapes underlain by permafrost. Highand low-centered polygons are typical but surprisingly, their role on hydrologic fluxes and stocks is not well quantified. We performed hydrologic modeling analyses using the physically-based model WaSiM-ETH that was forced by data from the Biocomplexity Experiment, Barrow, Alaska, (1999 to 2009) to assess the effect of ice-wedge polygon type on watershed-scale hydrology. Low-centered polygons, through elevated rims, reduced runoff while increasing evapotranspiration and surface water storage. The high-centered polygon landscape produced more than twice the runoff than the low-centered polygons, while storage and runoff drastically decreased. It is evident that microtopography plays an important role on the watershedscale hydrologic fluxes and stocks of low-gradient arctic wetlands. Permafrost degradation could transform lowinto highcentered polygons, which could potentially dominate the direct effects of climate change on arctic wetland hydrology.