Collaborative Research: Drainage network evolution following continental glaciation

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When the Pleistocene ice sheets retreated from low-elevation continental interiors (for example, the upper Midwest), they left behind vast low-relief plains dotted with wetland basins and few well-established streams. It is evident from looking at landscapes formed on glaciated plains of different ages that elaborate stream networks become established over time, reducing the abundance and extent of wetlands and increasing the extent of streams. However, the rate and mechanism of this "drainage integration" is unknown. The consequences of drainage integration are significant not only because erosional reshaping modifies the physical landscape, but also because it forges faster and more direct hydrological connections between uplands and streams. These hydrological connections have important implications for water resource management throughout these landscapes.This collaborative project will combine laboratory simulations, computer modeling of landscape evolution, and field and geospatial analysis of stream network evolution in real Midwestern landscapes uncovered by Pleistocene ice sheets at different times in the last ice age. Each effort will be aimed at understanding the processes and rates of channel extension and wetland basin breaching in real and simulated landscapes. The key objectives are to identify how natural processes of water flow and sediment transport in these settings govern the spatial patterns of evolving stream networks and their rate of development through time.