HR: 1340h
AN: PP23A-1083    [Abstracts]
TI: Satellite-based Paleo and Recent Lake Changes across the Tibetan Plateau
AU: * Sheng, Y
EM: ysheng@geog.ucla.edu
AF: Department of Geography, 1255 Bunche Hall University of California, Los Angeles (UCLA), Los Angeles, CA 90095,
AU: Luo, J
EM: yyljc@ucla.edu
AF: Department of Geography, 1255 Bunche Hall University of California, Los Angeles (UCLA), Los Angeles, CA 90095,
AU: Shah, C A
EM: cashah@ucla.edu
AF: Department of Geography, 1255 Bunche Hall University of California, Los Angeles (UCLA), Los Angeles, CA 90095,
AU: Kroll, C N
EM: cnkroll@esf.edu
AF: SUNY-ESF, 1 Forestry Dr., Syracuse, NY 13210,
AU: Li, X
EM: lixin@lzb.ac.cn
AF: Laboratory of Cryosphere and Environment, 260 West Donggang Road CAREERI, CAS, Lanzhou, 730000, China
AU: Yao, T
EM: tdyao@itpcas.ac.cn
AF: Institute of Tibetan Plateau Research, 18 Shuangqing Road, Beijing, 100085, China
AU: Wu, Y
EM: yxwu@nhri.cn
AF: Nanjing Hydraulic Research Institute, 223 Guangzhou Road, Nanjing, 210029, China
AB: The Tibetan Plateau, home to the world's largest high-altitude lake group, is experiencing significant climate change with a pronounced temperature rise of 0.16^oC per decade. Tibetan lakes have been impacted greatly, and in return they serve as a sensitive indicator of regional and global climate and water cycle variability. Past lake dynamics is essential for us to better understand the current and inferred future lake changes. Owing to fact that paleo lake shores have been extensively preserved on this remote plateau, paleo lake change since the late Pleistocene (about 25 ka BP) can be inferred with the assistance of digital elevation models from paleo shorelines visible on high-resolution imagery. We have recovered the lake extent more than 650 major contemporary lakes occupying a total area of 21,613 km², and it turns out that these lakes were broken from original 173 late Pleistocene mega lakes. The total lake area shrinkage and water loss are conservatively estimated at 42,109 km² and 2,936 km³ respectively. Nearly two-thirds of late Pleistocene lake area has disappeared. More recent lake dynamics over the past 30 years is monitored using archived satellite data, and only minor changes are found in most areas. The detected paleo and recent lake changes exhibit strong spatial patterns. Three distinct zones of paleo changes can be identified trending in the northeast to the southwest direction. Lakes in the first zone have only minor water-level drops (less than 20 meters). The second zone is the moderate zone, with 20-60 meter water level drops. Lakes in the third zone have the greatest water-level drop, up to 285 meters. Paleo shorelines are found extensively in this zone. The spatial distribution of the zones is found highly related to the Quaternary glaciation patterns. Glacial dynamics and stream network changes and other factors may explain the detected recent lake changes. It is found that glacial dynamics has the greatest impact on the detected paleo and recent lake changes, and will continue to play a critical role on Tibetan lake dynamics in the near future.
DE: 0746 Lakes (9345)
DE: 1630 Impacts of global change (1225)
DE: 1845 Limnology (0458, 4239, 4942)
DE: 1855 Remote sensing (1640)
DE: 9320 Asia
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2007 Fall Meeting