HR: 16:30h
AN: H44A-03    [Abstracts]
TI: Modeling of Potential Lahars Motivated by Landslides in Crater Lake of Baitoushan Volcano
AU: * Yu, Y
EM: yongyubj@hotmail.com
AF: Institute of Geology, China Seismological Bureau, Dewai Qijiahuozi,Beijing, Beijing, 100029 China
AU: Hong, H
AF: Institute of Geology, China Seismological Bureau, Dewai Qijiahuozi,Beijing, Beijing, 100029 China
AU: Wei, H
AF: Institute of Geology, China Seismological Bureau, Dewai Qijiahuozi,Beijing, Beijing, 100029 China
AU: Zheng, X
AF: Institute of Geology, China Seismological Bureau, Dewai Qijiahuozi,Beijing, Beijing, 100029 China
AU: Liu, P
AF: Institute of Geology, China Seismological Bureau, Dewai Qijiahuozi,Beijing, Beijing, 100029 China
AU: Tao, W
AF: Institute of Geology, China Seismological Bureau, Dewai Qijiahuozi,Beijing, Beijing, 100029 China
AB: Collapse and landslides, occurred in many volcanic craters, could result in more dangerous disasters if they encounter with lake water. Baitoushan volcano, an intraplate stratovolcano in the Changbaishan volcanic field on the border between China and North Korea, contains a crater lake approximately 4.45km in length along its long axis, about 200m in average depth. The lake is surrounded by steep rock walls that rise up to 300 $\sim$400m above its surface. Several horseshoe-shaped scars in the walls indicate that some large-scale landslides had happened since the last enormous explosive eruption one thousand years ago. At present the walls still have the possibilities of rockfalls and landslides. If they entered the lake with high speed, could produce life-threatening waves. The waves would transmit through the lake surface and release flood instantly to the downstream from the outlet in the north of the crater, which transform into lahars mixing with the loose pyroclastic deposits along the hillslope, and destroy almost everything where they passed by. Our work aims to model the potential lahars motivated by the landslides of Baitoushan volcano and to predict inundation areas and travel time of flows. For this purpose the heights of waves triggered by those historic landslides have been estimated based on declivities­_ volumes and landslide speeds. HEC-RAS, a program of surface water model developed by U.S. Army Corps of Engineers, is utilized to simulate the potential lahars using the range of wave height as the boundary condition. The research results indicate that the lahars, on the one hand, might spend about eighty minutes reaching the nearest town at the foot of the volcano along Erdaobaihe River valley, and on the other hand possibly flood into the nearby rivers if the flux is remarkably large.
DE: 3210 Modeling
DE: 1749 Volcanology, geochemistry, and petrology
DE: 1821 Floods
SC: Hydrology [H]
MN: 2004 AGU Fall Meeting