An analysis of an arctic channel network using a digital elevation model

Abstract

Drainage basins possess spatial patterns of similarity that can be characterized by universal qualities in the fractal dimension and the cumulative area distribution. Features called water tracks often drain hillslopes in basins with permafrost and impose significant control on the hydrologic response of watersheds. We analyzed the arrangement of channel networks and water tracks in Imnavait Creek in Northern Alaska to determine if basins with permafrost possess the same universal characteristics as basins without permafrost. Using digital elevation models (DEMs), we explored the hillslope/channel scaling regimes, the spatial distribution of mass through the cumulative area distribution, and the fractal characteristics of channel networks in the Kuparuk River basin in Northern Alaska. Fractal analysis, slope–area analysis, and field mapping suggest that water tracks are positioned on the hillslopes where channels should occur. Fully-developed channel networks, however, possess certain universal characteristics in aggregation patterns that are manifested in a common cumulative area distribution. Imnavait Creek possesses those universal characteristics only above the scale of the hillslope water track, or when the drainage areas reach the main channels in the valley bottom. Our interpretation is that a rudimentary channel network formed on the hillslopes, but never developed into a mature channel network because permafrost is limiting erosion. Consequently, the undissected hillslopes are extensive. Given the dependence of permafrost on a cold climate, a warming climate and subsequent degradation of permafrost may have significant impacts on the erosional development of channel networks in the Arctic.