Title: Sediment Production in Mountain River Systems

Speaker: John Pitlick, Geography Department, CU-Boulder

Abstract: In this talk I will present findings from recent research to quantify rates of sediment 
production in rivers draining the French Alps.  After a brief overview of the processes governing 
sediment production, I will present results from a year-long study focusing on rivers draining 
the Ecrins Massif in southeastern France.  This is an area of very high relief and contrasting 
rock types where sediment production appears to be high.  Annual bed load sediment yields are 
modeled for 15 separate locations by coupling relations for sediment transport with relations for 
flow frequency.  Results indicate that annual sediment yields of rivers draining the Ecrins 
Massif are much higher than areas of comparable relief and climate in the Rocky Mountains, 
suggesting that differences in sediment production largely reflect differences in underlying rock 
type.  In addition, I will suggest that contemporary rates of sediment production are comparable 
to long-term rates determined from studies of the geologic history of the area.