Analyses results of total peatland area changes in the southern AItay Mountain region over the past 20 years are discussed in this paper. These analyses were based on remote sensing (RS) and geographical information...Analyses results of total peatland area changes in the southern AItay Mountain region over the past 20 years are discussed in this paper. These analyses were based on remote sensing (RS) and geographical information system (GIS) studies. Possible control methods are evaluated by comparing these results to other regional records and climate data. The area of the peatland zones was calculated by overlaying a peatland layer of Landsat TM (Thematic Map) image constructed by using supervised classification with a layer of slope based on a digital elevation model (DEM). The results show that slope layer is crucial to improving the accuracy of peatland extracted from TM images. The peatland area of the Altay Mountains increased from 931.5km^2 in 1990 to 977.7 km^2 in 2010. This trend is consistent with the climate change in this region, due in part to increasing temperatures and precipitation, suggesting possible climate controls on peatland expansion. The increase in the peatland area in the Altay Mountains over the last 20 years has been influenced by the westerlies. Alternatively, changes in the largest highland peatland area of the Zoige Basin, located in the eastern Tibetan Plateau have been influenced by the intensity of the Asian summer monsoons. In addition to increased temperatures, decreased precipitation in the Zoige Basin and increased precipitation in the Altay Mountains, due to varied patterns of atmospheric circulation, are the probable causes for driving the change differences in these two peatland areas.展开更多
基金Acknowledgements We thank the reviewers for their beneficial ideas. This research was supported by the 100 Talents Programme of the Chinese Academy of Sciences and the National Natural Science Foundation of China (Grants Nos. 41125006 and 41071126).
文摘Analyses results of total peatland area changes in the southern AItay Mountain region over the past 20 years are discussed in this paper. These analyses were based on remote sensing (RS) and geographical information system (GIS) studies. Possible control methods are evaluated by comparing these results to other regional records and climate data. The area of the peatland zones was calculated by overlaying a peatland layer of Landsat TM (Thematic Map) image constructed by using supervised classification with a layer of slope based on a digital elevation model (DEM). The results show that slope layer is crucial to improving the accuracy of peatland extracted from TM images. The peatland area of the Altay Mountains increased from 931.5km^2 in 1990 to 977.7 km^2 in 2010. This trend is consistent with the climate change in this region, due in part to increasing temperatures and precipitation, suggesting possible climate controls on peatland expansion. The increase in the peatland area in the Altay Mountains over the last 20 years has been influenced by the westerlies. Alternatively, changes in the largest highland peatland area of the Zoige Basin, located in the eastern Tibetan Plateau have been influenced by the intensity of the Asian summer monsoons. In addition to increased temperatures, decreased precipitation in the Zoige Basin and increased precipitation in the Altay Mountains, due to varied patterns of atmospheric circulation, are the probable causes for driving the change differences in these two peatland areas.