Seasonal Accumulation and Depletion of Local Sediment Stores of Four Headwater Catchments

Water

Sarah E. Martin²  Martha H. Conklin¹ 

[1] Sierra Nevada Research Institute at the University of California, Merced, 5200 N Lake Rd., Merced, CA 95343, USA;

关键词: hysteresis;    sediment;    snowmelt;    storm event;    turbidity;   

DOI  :  10.3390/w6072144

来源: mdpi

【 摘 要 】

Seasonal turbidity patterns and event-level hysteresis analysis of turbidity verses discharge in four 1 km² headwater catchments in California’s Sierra Nevada indicate localized in-channel sediment sources and seasonal accumulation-depletion patterns of stream sediments. Turbidity signals were analyzed for three years in order to look at the relationships between seasonal turbidity trends, event turbidity patterns, and precipitation type to stream sediment production and transport. Seasonal patterns showed more turbidity events associated with fall and early to mid- winter events than with peak snow-melt. No significant turbidity patterns emerged for periods of snow melt vs. rain. Single event hysteresis loops showed clockwise patterns were dominant suggesting local sediment sources. In successive discharge events, the largest turbidity spike was often associated with the first but not necessarily the largest discharge event-indicating seasonal depletion of local sediment stores. In multi-peaked discharge events, hysteresis loops shifted from clockwise to linear or random patterns suggesting that localized sediment stores are being used up and sufficient flow energy must be reached to start entraining the more consolidated bank/bed sediment or that dominant sediment sources may be shifting to less localized areas such as hill slopes. A conceptual model with phases of accumulation and transport is proposed.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.