An Experimental Study of Drainage Network Development by Surface and Subsurface Flow in Low-Gradient Landscapes Raster Datasets

Sockness, Brian; Gran, Karen B.

doi:10.13020/7a27-tg76

Cited by 1 publication

(1 citation statement)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Data availability. All data are available through the University of Minnesota Digital Conservancy (Sockness and Gran, 2021, https://doi.org/10.13020/7a27-tg76) including all raw DEM data as TIFF files and JPEG images as well as analyzed data in ArcGIS map package files. Data are also linked to the MS thesis of Brian Sockness (2020) at https://hdl.handle.net/11299/213050.…”

Section: Competing Interestsmentioning

confidence: 99%

An experimental study of drainage network development by surface and subsurface flow in low-gradient landscapes

Sockness

Gran

2022

Earth Surf. Dynam.

View full text Add to dashboard Cite

Abstract. How do channel networks develop in low-gradient, poorly drained landscapes? Rivers form elaborate drainage networks with morphologies that express the unique environments in which they developed, yet we lack an understanding of what drives channel development in low-gradient landscapes like those left behind in the wake of continental glaciation. To better understand what controls the erosional processes allowing channel growth and integration of surface water non-contributing areas (NCAs) over time, we conducted a series of experiments in a small-scale drainage basin. By varying substrate and precipitation, we could vary the partitioning of flow between the surface and subsurface, impacting erosional processes. Two different channel head morphologies developed, interpreted as channel growth via overland flow and seepage erosion. Channel growth was dominated by overland flow vs. seepage erosion depending on substrate composition, rainfall rate, and drainage basin relief. Seepage-driven erosion was favored in substrates with higher infiltration rates, whereas overland flow was more dominant in experiments with high precipitation rates, although both processes occurred in all runs. Overland flow channels formed at the onset of experiments and expanded over a majority of the basin area, forming broad dendritic networks. Large surface water contributing areas (CAs) supported numerous first-order channels, allowing for more rapid integration of NCAs than through seepage erosion. When overland flow was the dominant process, channels integrated NCAs at a similar, consistent rate under all experimental conditions. Seepage erosion began later in experiments after channels had incised enough for exfiltrating subsurface flow to initiate mass wasting of headwalls. Periodic mass wasting of channel heads caused them to assume an amphitheater-shaped morphology. Seepage allowed for channel heads to expand with smaller surface water CAs than overland flow channels, allowing for network expansion to continue even with low surface CAs. Seepage-driven channel heads integrated NCAs more slowly than channel heads dominated by overland flow, but average erosion rates in channels extending through seepage erosion were higher. The experimental results provide insight into drainage networks that formed throughout areas affected by continental glaciation, and highlight the importance of subsurface hydrologic connections in integrating and expanding drainage networks over time in these low-gradient landscapes.

show abstract

Section: Competing Interestsmentioning

confidence: 99%