CUERE Seminar: John T. Kemper, UMBC
Location
Technology Research Center (TRC) : 206
Date & Time
February 9, 2018, 2:00 pm – 3:00 pm
Description
Center for Urban Environmental Research and Education
Spring 2018 Seminar Series
presents
"Spatial and temporal patterns of suspended sediment transport in nested urban watersheds"
2:00 PM
TRC 206, UMBC
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Parking policy
Parking passes for off-campus guests in the TRC lot are required at the cost of $4.00 per car. Parking passes may be picked up and paid for (cash only) before seminar by stopping by the CUERE office in TRC 102 /105 and seeing a staff member. Please contact us at 410-455-1763 with any questions regarding logistics.
View our web site at http://cuere.umbc.edu
Abstract
Near real-time turbidity and discharge data have been collected continuously for more than four years at five stream gages representing three nested watershed scales (1-2 sq km, 5-6 sq km, 14 sq km) in the highly impervious Dead Run watershed. In-stream turbidity sensors were used in conjunction with field samples of suspended sediment to create turbidity-concentration relationships, by which turbidity time series were transformed into suspended sediment concentration time series. Patterns of sediment concentration and yield were examined to investigate questions concerning sediment exhaustion, transport- or supply-limited regime, and the role of sediment storage.
Evidence of potential sediment exhaustion was found at the intra-storm time scale, in the form of reduced concentration peaks during the latter streamflow pulse of a multi-peak event, and at the seasonal scale, with the occurrence of lower yields for equivalent discharges in the fall compared to the spring and summer. Little evidence was found for sediment exhaustion across storms, with equivalent sediment concentration peaks for seperate storm events within a short time scale.
Sediment yields have been calculated for 100+ different storms across four years. Clear positive correlations between suspended sediment yield and discharge at each watershed scale suggest that the watershed operates under a transport-limited regime. Similar relationships in the downstream direction suggest that entire watershed operates under this same regime.Storm yields show significant spatial variation, both at equivalent sub-watershed scales and from headwaters to mouth. Greater yields with increasing watershed size for three of the four nested watershed pairs suggest that storage plays a somewhat minimal role in catchment sediment dynamics. The fine-scale design of this study represents a unique opportunity to compare and contrast sediment yields across a variety of spatial and temporal scales, and provide insight into sediment transport dynamics within an urbanized watershed.
