The 18 May 1980 eruption of Mount St. Helens, emplaced between 3-3.5 billion cubic yards (bcy) of poorly sorted material ranging from silt to boulders, extending from river mile (RM) 25 to RM 38 in the upper North Fork Toutle River drainage. Sediment yields from the debris avalanche were calculated...
Chameleon is a physics-based landscape modeling software system designed for modeling and simulations applications. Hyperspectral laboratory, field, and imaging spectrometer measurements are collected as empirical foundation data. Linear spectral unmixing is performed to decompose each image pixel into spectral endmembers. Mathematical manipulation of these fractional abundances and introduction of new...
Map delineations of soil and vegetation for a 14,000
acre (5,800 hectare) site in the Oregon Coast Range were
compared. Research objectives were to ascertain the
types of information that could be extracted from delineation
comparisons and to develop a methodology suited
to this purpose. The latter objective was achieved...
Geographical geomorphology is a young science with a long,
complex history closely paralleling the growth and development of
geology. From an enthusiastic beginning under the tutelage of
William Morris Davis, geographical geomorphology rapidly lost its
influence and stature in geography. Today there is a sense of
purpose and direction that...
The ocean wave conditions at the mouth of the Columbia River have
long proven a hazard to ship navigation. Over 62 major shipwrecks
have occurred at, or in the vicinity of the river entrance. The wave
pattern is extremely complex, varying seasonally with prevailing winds
and river discharge, as well...
The John Day Reservoir, a large reservoir between the John Day and the McNary Dams on the Columbia River, must be lowered several feet below design level during salmon migration season in order to preserve anadromous fish habitat. This research assessed the north shore of the John Day Reservoir for...
Hart Mountain is a basaltic fault block mountain
in the semi-desert region of the northern Basin and Range
province in south-central Oregon. Geomorphic processes
associated with lingering snowpatches have formed nivation
hollows, which are small scale depressions in the hillsides.
The lingering snow in the hollows prohibits shrub
growth. Bedrock...
A log step develops when large woody debris extends across the active
channel, creating a change in the water surface elevation as the stream
spills over the log step. By forming a series of vertical falls, log
steps reduce the amount of potential energy available for conversion to
kinetic energy...