Glacierized Area Variation and Its Response to Climate Change in Qangtang Plateau during 1970—2000
Updatetime：2012-01-16From：
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Global warming has a great impact on glacier variations and is the focus of the various studies. The glaciers are more sensitive in the Tibetan Plateau than in Polar Regions. Thus, it is of significance to research glaciers in the Qangtang Plateau, the hinterland of the Tibetan Plateau.
In this research, Tupu analysis is performed for glacierized area variation during 1970-2000 in the Qangtang Plateau using air photos, photogrammetric maps and satellite images based on the theories and methods of Geo-information Tupu. The result clearly reveals that a few glaciers were actually advancing during 1970-2000 in the Qangtang Plateau. However, the glaciers tended to decrease by a rate of 0.145%/a from 1970 to 2000 with an annual recession area of 3.004 km2 as a whole. Glacier ablation accelerated during 1970—2000, but the retreat rate seemed much less in the study area than that in the most areas of western China. This is because the glaciers in the study area belonged to the extremely\|continental type, which responded to climate change slowly. The whole glacier variation in the Qangtang Plateau increased from nouth to south. However, there existed differences in different mountains during different periods.
Air temperature rose distinctly, especially the average temperature in warm season, and precipitation mainly increased during 1970-2000 in the Qangtang Plateau. However, the glacier accumulation due to the increasing precipitation was not sufficient to offset glacier ablation due to air temperature warming. Therefore, it is considered that glacier retreat was likely due to air temperature warming during 1970-2000 in the Qangtang Plateau.
The functional model of glacier system is used to predict the glacier variation. The results show that the linear warming with temperature rising rate of 0.03 K·a-1 is much more logical with the real situation of glacier variation than other scenarios after contrasting the predicted results with investigation results. This also demonstrates that the functional model of glacier system is feasible.
In this research, Tupu analysis is performed for glacierized area variation during 1970-2000 in the Qangtang Plateau using air photos, photogrammetric maps and satellite images based on the theories and methods of Geo-information Tupu. The result clearly reveals that a few glaciers were actually advancing during 1970-2000 in the Qangtang Plateau. However, the glaciers tended to decrease by a rate of 0.145%/a from 1970 to 2000 with an annual recession area of 3.004 km2 as a whole. Glacier ablation accelerated during 1970—2000, but the retreat rate seemed much less in the study area than that in the most areas of western China. This is because the glaciers in the study area belonged to the extremely\|continental type, which responded to climate change slowly. The whole glacier variation in the Qangtang Plateau increased from nouth to south. However, there existed differences in different mountains during different periods.
Air temperature rose distinctly, especially the average temperature in warm season, and precipitation mainly increased during 1970-2000 in the Qangtang Plateau. However, the glacier accumulation due to the increasing precipitation was not sufficient to offset glacier ablation due to air temperature warming. Therefore, it is considered that glacier retreat was likely due to air temperature warming during 1970-2000 in the Qangtang Plateau.
The functional model of glacier system is used to predict the glacier variation. The results show that the linear warming with temperature rising rate of 0.03 K·a-1 is much more logical with the real situation of glacier variation than other scenarios after contrasting the predicted results with investigation results. This also demonstrates that the functional model of glacier system is feasible.
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