Vu Phan Hien博士——遙感科學(xué)國(guó)家重點(diǎn)實(shí)驗(yàn)室2016年系列學(xué)術(shù)講座之五十一
來源:發(fā)布時(shí)間:2016-12-09
報(bào)告摘要:
The Tibetan Plateau has the largest glacier covered area outside the Poles, and there are thousands of lakes on this region. Changes in water storage of open water bodies can be assessed by analysing changes in their water levels. Therefore, estimating the water storage change of the Tibetan Plateau requires estimating changes in glacial thickness and lake level. In this study, we observe changes in glacial thickness and lake level on the Tibetan Plateau integrating the ICESat laser altimetry data and other data products derived from remotely sensed data and then recognize obviously their relationship. Firstly, trends in the estimated thickness of 90 glacial areas on the whole Tibetan Plateau were estimated by exploiting ICESat GLA14 land surface elevation data in combination with the SRTM DEM and the GLIMS glacier mask. Then, water level variations of 154 lakes spread all over the Tibetan Plateau could be obtained by using the ICESat GLA14 land surface elevation data in combination with the MODIS land water mask. Finally, geometric links between glaciers and lakes on the Tibetan Plateau were determined by applying a surface flow network analysis in catchments with both a lake and a glacier. The surface flow network was based on the HydroSHEDS product which was derived from the SRTM digital elevation model data. The results indicated that 25.3% of the glaciers release their melt water directly to 244 lakes. In general, the geometric dependency of Tibetan lakes on glacial runoff presented a simple representation of a potential relationship between changes in glacier thickness and lake levels. Moreover, the current results on glacial and lake level changes are expected to contribute the understanding of the hydrologic processes and the input data of the water balance model of the Tibetan Plateau.
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