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Gravel sediment routing from widespread, low-intensity landscape disturbance, Current River basin, Missouri

Earth Surface Processes and Landforms

By:
,
DOI: 10.1002/(SICI)1096-9837(199909)24:10<897::AID-ESP18>3.0.CO;2-6

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Abstract

During the last 160 years, land-use changes in the Ozarks have had the potential to cause widespread, low-intensity delivery of excess amounts of gravel-sized sediment to stream channels. Previous studies have indicated that this excess gravel bedload is moving in wave-like forms through Ozarks drainage basins. The longitudinal, areal distribution of gravel bars along 160 km of the Current River, Missouri, was evaluated to determine the relative effects of valley-scale controls, tributary basin characteristics, and lagged sediment transport in creating areas of gravel accumulations. The longitudinal distribution of gravel-bar area shows a broad scale wave-like form with increases in gravel-bar area weakly associated with tributary junctions. Secondary peaks of gravel area with 1.8-4.1 km spacing (disturbance reaches) are superimposed on the broad form. Variations in valley width explain some, but not all, of the short-spacing variation in gravel-bar area. Among variables describing tributary drainage basin morphometry, present-day land use and geologic characteristics, only drainage area and road density relate even weakly to gravel-bar areal inventories. A simple, channel network-based sediment routing model shows that many of the features of the observed longitudinal gravel distribution can be replicated by uniform transport of sediment from widespread disturbances through a channel network. These results indicate that lagged sediment transport may have a dominant effect on the synoptic spatial distribution of gravel in Ozarks streams; present-day land uses are only weakly associated with present-day gravel inventories; and valley-scale characteristics have secondary controls on gravel accumulations in disturbance reaches.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Gravel sediment routing from widespread, low-intensity landscape disturbance, Current River basin, Missouri
Series title:
Earth Surface Processes and Landforms
DOI:
10.1002/(SICI)1096-9837(199909)24:10<897::AID-ESP18>3.0.CO;2-6
Volume
24
Issue:
10
Year Published:
1999
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
First page:
897
Last page:
917
Number of Pages:
21