College of LAS Events

View Full Calendar

If you will need disability-related accommodations in order to participate, please email the contact person for the event.
Early requests are strongly encouraged to allow sufficient time to meet your access needs.

Suspended Sediment Dynamics in an Intensively Managed Agricultural Landscape: Floodplain-Channel Connectivity, Seasonality, and Event-Based Variability

Event Type
Department of Geography & GIS
2049 Natural History Building
Mar 3, 2023   3:00 pm  
Chelsy Salas, GGIS PhD Student
This event is free and open to GGIS students
Originating Calendar
Geography and Geographic Information Science

Suspended sediment dynamics describe the production, delivery, and transport of sediment to rivers and reflect complex interactions among watershed-scale hydrology and geomorphology. Changes in flow or upstream supply of sediment, such as the quantity or grain size, can cause geomorphic changes to the river-channel form as well as the floodplain environment. Land use dominated by agricultural practices and longitudinal variations in bank elevations complicate known processes of suspended sediment dynamics by altering the way in which water and sediment move throughout a watershed over time and space. Additional complications arise when biases related to fine sediment are introduced through different methods of sediment sampling, thereby affecting suspended sediment concentration analyses used to evaluate relationships between sediment load and discharge. This study examines sediment dynamics in the Upper Sangamon River Basin (USRB) of Illinois, an intensively managed watershed dominated by row-crow agriculture and on the agriculturally undisturbed Allerton Park floodplain, located within the USRB. The objectives involve (1) understanding the relationships among suspended sediment dynamics and intensively managed watersheds using sediment rating curve analysis over event and seasonal timescales (2) examining spatial and temporal variations in floodplain deposition and suspended-sediment concentrations during flood events of different magnitudes (3) and assessing fine sediment biases of suspended sediment concentration analysis performed on sediment samples obtained by automatic samplers with different sampling capacities. Preliminary findings show that delivery of sediment to floodplains by floodwater is complex and varies both spatially and temporally among and within different floodplain geomorphic environments. At the watershed scale, sediment concentrations and loads vary substantially over seasonal and event timescales. Results of this research will advance understanding of sediment dynamics in river systems of intensively managed landscapes by quantifying spatial and temporal variability in these dynamics at the catchment-scale and by providing insight into hydrogeomorphological conditions controlling channel-floodplain connectivity. It will also help to determine the representativeness of different suspended sediment sampling methods for accurately characterizing suspended sediment concentrations and loads.

link for robots only