HR: 0800h
AN: H31A-1264    [Abstracts]
TI: Investigation of the Transient Response of Gower Gulch to Forced Diversion, Death Valley, California
AU: * Schultz, L L
EM: schultli@gmail.com
AF: Dept. of Geology and Geophysics, Boston College, 140 Commonwealth Ave., Chestnut Hill, MA 02467 United States
AU: Snyder, N P
EM: noah.snyder@bc.edu
AF: Dept. of Geology and Geophysics, Boston College, 140 Commonwealth Ave., Chestnut Hill, MA 02467 United States
AB: We document sequential stages of the evolution of Gower Gulch in response to a forced diversion in 1941, using aerial photographs and field surveys. This artificial stream capture provides a rare opportunity to evaluate initial channel conditions and the ongoing response of the system. Five sets of aerial photographs (flight dates 1948, 1960, 1971, 1982, and 1995) have been orthorectified or registered for thorough geomorphic analysis. The response differs throughout the channel, depending on pre-diversion conditions and lithology. At the diversion point and the mouth, bedrock-floored knickzones have formed. Channel narrowing and incision characterize these steep reaches, with upstream knickpoint migration by pothole abrasion. In the central part of the channel, underlain by soft, fine-grained sedimentary rocks, the channel is covered in alluvium and has widened from an average of 14.8 m in 1948 to 24.6 m in 2005. Incision in this area is approximately 1-3 m, as indicated by tributary terraces. In the alluvial fan, the channel has incised up to 6.9 m, and widened from 10.9 m to 45.6 m. Above the diversion, Furnace Creek Wash has narrowed by approximately 12 meters since 1948.
DE: 1815 Erosion
DE: 1825 Geomorphology: fluvial (1625)
DE: 1834 Human impacts
SC: Hydrology [H]
MN: Fall Meeting 2005