Based on Landsat MSS/TM/OLI remote sensing images,glaciers vector data in the Qaidam Basin were extracted for 1977,2002,and 2018,and their spatial-temporal variations were analyzed.Results show that there were 2,050 g...Based on Landsat MSS/TM/OLI remote sensing images,glaciers vector data in the Qaidam Basin were extracted for 1977,2002,and 2018,and their spatial-temporal variations were analyzed.Results show that there were 2,050 glaciers covering an area of 1,693.54±40.96 km2 and having an ice volume of 108.65±2.43 km^3 in the Qaidam Basin in 2018.Glaciers with areas<1.0 km2 accounted for the largest number,while glaciers with areas of 1.0−5.0 km2 accounted for the most glacierized area.In the past 50 years,the number of glaciers decreased by 177,and the glacier area and volume reduced by 338.08 km2(−8.12 km^2/a)and 19.92 km3(−0.48 km^3/a),respectively.Retreat altitudes of glaciers were concentrated at 4,900−5,600 m,4,700−5,200 m,and 5,000−5,600 m and reduced areas accounted for 95.53%,77.80%,and 69.19%in the Kunlun,Qilian,and Altun mountains,respectively.The area of north-oriented glaciers decreased the most(−125.43 km^2),but the west-and east-oriented glaciers retreated at the fastest rate(i.e.,−27.11%and−27.10%).All glaciers showed a decreasing trend in sub-regions of the Qaidam Basin from 1977 to 2018.The decreasing trend was accelerated gradually from northwest to southeast in the northern part of the basin,while glacier change was the smallest in the middle section and gradually accelerated towards both ends of the basin's southern part.The temperature had continued to rise,and the precipitation had increased slowly in the Qaidam Basin during the past 50 years.The continuous rise in air temperature was the main reason for the retreat of glaciers.展开更多
文摘Based on Landsat MSS/TM/OLI remote sensing images,glaciers vector data in the Qaidam Basin were extracted for 1977,2002,and 2018,and their spatial-temporal variations were analyzed.Results show that there were 2,050 glaciers covering an area of 1,693.54±40.96 km2 and having an ice volume of 108.65±2.43 km^3 in the Qaidam Basin in 2018.Glaciers with areas<1.0 km2 accounted for the largest number,while glaciers with areas of 1.0−5.0 km2 accounted for the most glacierized area.In the past 50 years,the number of glaciers decreased by 177,and the glacier area and volume reduced by 338.08 km2(−8.12 km^2/a)and 19.92 km3(−0.48 km^3/a),respectively.Retreat altitudes of glaciers were concentrated at 4,900−5,600 m,4,700−5,200 m,and 5,000−5,600 m and reduced areas accounted for 95.53%,77.80%,and 69.19%in the Kunlun,Qilian,and Altun mountains,respectively.The area of north-oriented glaciers decreased the most(−125.43 km^2),but the west-and east-oriented glaciers retreated at the fastest rate(i.e.,−27.11%and−27.10%).All glaciers showed a decreasing trend in sub-regions of the Qaidam Basin from 1977 to 2018.The decreasing trend was accelerated gradually from northwest to southeast in the northern part of the basin,while glacier change was the smallest in the middle section and gradually accelerated towards both ends of the basin's southern part.The temperature had continued to rise,and the precipitation had increased slowly in the Qaidam Basin during the past 50 years.The continuous rise in air temperature was the main reason for the retreat of glaciers.
