aggradation and sediment in the nisqually river
DESCRIPTION
Presentation given by Chris Magirl, USGSTRANSCRIPT
Preliminary results subject to change
Preliminary results subject to change
Preliminary results subject to change * Assumes 1.65 tonnes/m3 bulk density
Total load = 1,200,000 ± 130,000 t/yr
(Assumes reservoir trap efficiency of 90%)
Total load = 7,800 ± 2,600 t/yr
Total load ~ 120,000 t/yr
USGS Provisional data; subject to change
USGS Provisional data; subject to change
From Czuba et al. (2011)
From Czuba et al. (2011)
Carbon River (July 2011)
White River (June 2009)
Nisqually River (November 2010)
Tahoma Creek (November 2010) Photo courtesy Dean Koepfler, staff photographer © The Tacoma News Tribune
Topography
Preliminary results subject to change
1994 2009
Aerial imagery analysis (Carbon River)
Preliminary results subject to change
Active-channel width in 2009
USGS Provisional data; subject to change
Active-channel width change, 1965-1994
USGS Provisional data; subject to change
Active-channel width change, 1994-2009
USGS Provisional data; subject to change
Lahar
Crandle (1971, p. 3):"The term 'lahar' is an Indonesian word that is used...as a general designation for deposits that have resulted from rapid mass flowage of rock debris mobilized by water and that have originated on the slopes of a volcano."
Pierson and Scott (1985, p. 1512): "The Indonesian word 'lahar' denotes a debris flow or a mudflow that originates from a volcano, whether triggered by an eruption or not."
Movie available on YouTube: search “Mount Rainier debris flow”
• Movie by Paul Kennard of the National Park Service • Debris flows ~80% sediment by weight; consistency of cement; float boulders like fishing bobbers • Dominant downstream sediment-transport mechanism
USGS Provisional data; subject to change
Increasing floods peaks??
Mastin et al. (2009)
Snoqualmie River near Carnation, Washington
From long-term gages, no regional trend in the Pacific Northwest
Hirsch and Ryberg (2011)
Mass et al. (2011)
Increase in floods peaks a predicted response to climate change
USGS Provisional data; subject to change
Mount Rainier rivers:
Carbon Glacier (July 2011)
USGS Provisional data; subject to change
Based on Cui’s TUGS model -- Wilcock & Crowe, 2003 -- particle attrition
USGS Provisional data; subject to change
USGS Provisional data; subject to change
USGS Provisional data; subject to change
