HR: 14:10h
AN: H53I-02 INVITED     [Abstracts]
TI: New Sediment Flux Models Provides key to Understanding the Response of High-latitude Landscapes to Climate Forcing
AU: * Syvitski, J P
EM: syvitski@colorado.edu
AF: INSTAAR, Univ Colorado, Boulder, CO 80309-0450 United States
AU: * Syvitski, J P
EM: syvitski@colorado.edu
AF: VIMS, College of William & Mary, Gloucester Point, VA 23062 United States
AB: New global models (BART, QBRT) for the estimation of the long-term flux of sediment delivered by rivers to the coastal zone can account for 96 percent of the data variance in observations. The models capture: 1) tectonics through basin area and relief, 2) lithology, 3) glacier coverage, 4) human activities (soil erosion, reservoir trapping), and 5) climate through runoff and temperature. The climate factors reflect precipitation dynamics, weathering intensity, and the natural state of landscape vegetation. With warming in the arctic, runoff will increase. As the landscape warms, precipitation will regionally increase both in magnitude and intensity, plant activity and soil development will increase, permafrost will melt, and the runoff season will lengthen --- all of which contribute to increased sediment production and transport. The BART/QBRT model provides a framework to understand how arctic landscapes are likely to change through a period of protracted warming. Another model, HydroTrend, is more able to track sediment dynamics between steady-state conditions. When applied to warming landscapes with glaciers, HydroTrend simulates an increase in meltwater production (release of stored water), and an increase in sediment discharge. However as glaciers reach new higher-elevation equilibrium altitudes, all models show that sediment flux will decrease.
DE: 1620 Climate dynamics (0429, 3309)
DE: 1622 Earth system modeling (1225)
DE: 1815 Erosion
DE: 1825 Geomorphology: fluvial (1625)
DE: 1862 Sediment transport (4558)
SC: Hydrology [H]
MN: Fall Meeting 2005