Abstract
Abstract. The Tibetan plateau is covered by hundreds of larger and smaller lakes. Until recently there was no method to monitor their water level variations due to lack of in-situ measurements or unfitness of available remote sensing methods. However the ICESat/GLA14 laser altimetry data provide global surface elevations for land during 18 one-month campaigns between 2003 and 2009. This product could be used to accurately monitor water level variations and to estimate annual water level trends of about 150 Tibetan lakes. Based on the ICESat campaign schedule, lake levels derived from the GLA14 data are classified into three groups referenced to the Tibetan seasons: late dry, early wet, and early dry. For each lake sampled by sufficient ICESat campaigns, seasonal water level trends could be estimated and inter-seasonal lake level variations could be determined. The results indicate that most of the southern Tibetan lakes have a downward seasonal trend while most lakes elsewhere in Tibet have a positive seasonal trend. This means that these seasonal trends are similar to the annual trends. Moreover, lake level variations between seasons are much larger in the south than in the north and the west of Tibet. Based on the spatial pattern of the lakes, the Tibetan plateau is divided into four sub-areas corresponding to seasonal lake level trends and inter-seasonal lake level variations. The results confirm climatic trends as discussed in meteorological literature. Therefore, this analysis is expected to improve the understanding of the limnological processes on the Tibetan plateau and their impacts on the surrounding regions.
Highlights
The Tibetan Plateau is the highest and largest plateau of the world but is called the Third Pole as it stores a large amount of ice in its thousands of glaciers
The lake levels were derived from Release 31 ICESat/GLA14 data (NSIDC, 2011) while locations of the Tibetan lakes were determined based on the MODIS land-water mask (GLCF, 2011)
The result indicates that RMSEs of the seasonal water level trends less than 30 cm are 86% of the 121 lakes observed between late dry seasons, 88% of the 41 lakes between early wet seasons, and 57% of the 123 lakes between early dry seasons
Summary
The Tibetan Plateau is the highest and largest plateau of the world but is called the Third Pole as it stores a large amount of ice in its thousands of glaciers. It is the source of all major rivers in South-East Asia, the most densely populated region on Earth. Most of the annual rainfall occurs between May and September, when the Tibetan plateau is influenced by the Indian and East Asian monsoons, as mentioned in (Zhisheng et al, 2001). (Tao et al, 2004) concluded that the south of Tibet becomes warmer and wetter with a clear increase in rainfall as well, while a part of the north turns
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
