HR: 0800h
AN: C21B-0476    [Abstracts]
TI: MODIS-based Snow Cover Variability of the Upper River Grande Basin
AU: * yu, b
EM: beibeiyu1677@yahoo.com
AF: Laboratory of Remote Sensing and Geoinformatics, UTSA, one UTSA circle, san antonio, tx 78249, United States
AU: wang, x
EM: Xianwei.Wang@utsa.edu
AF: Laboratory of Remote Sensing and Geoinformatics, UTSA, one UTSA circle, san antonio, tx 78249, United States
AU: xie, h
EM: Hongjie.Xie@utsa.edu
AF: Laboratory of Remote Sensing and Geoinformatics, UTSA, one UTSA circle, san antonio, tx 78249, United States
AB: Snow cover and its spring melting in the Upper Rio Grande Basin provides a major water source for the Upper to Middle Rio Grande valley and Elephant Butte Reservoir. Thus understanding the snowpack and its variability in the context of global climate change is crucial to the sustainable water resources for the region. MODIS instruments (on Terra and Aqua) have provided time series of snow cover products since 2000, but suffering with cloud contaminations. In this study, we evaluated four newly developed cloudless snow cover products (less than 10%) and four standard products: daily (MOD10A1, MYD10A1) and 8-day (MOD10A2, MYD10A2), in comparison with in situ Snowpack Telemetry (SNOTEL) measurements for the hydrological year 2003-2004. The four new products are daily composite of Terra and Aqua (MODMYD10DC), multi-day composites of Terra (MOD10MC), Aqua (MYD10MC), and Terra and Aqua (MODMYD10MC). The standard daily and 8-day products can classify land correctly, but had fairly low accuracy in snow classification due to cloud contamination (a average of 39.4% for Terra and 45% for Aqua in the year 2003-2004). All the new multi-day composite products tended to have high accuracy in classifying both snow and land (over 90%), as the cloud cover has been reduced to less than 10% (~5% for the year) under the new algorithm . This result is consistent with a previous study in the Xinjiang area, China (Wang and Xie, 2007). Therefore, MOD10MC (before the Aqua data available) and MODMYD10MC products are used to get the mean snow cover of the Upper Rio Grande Basin from 2000 to 2007. The snow depletion curve derived from the new cloud-free snow cover map will be used to examine its effect on stream discharge.
UR: http://www.utsa.edu/LRSG/
DE: 0736 Snow (1827, 1863)
DE: 0740 Snowmelt
DE: 0758 Remote sensing
DE: 1879 Watershed
SC: Cryosphere [C]
MN: 2007 Fall Meeting