李虹蓉 楊太保 田洪陣
摘要利用1987和2015年Landsat遙感影像解譯分析祁連山地區冰川變化,研究冰川變化的影響因素。結果表明,祁連山冰川退縮較為嚴重,面積從1987年的2 072.7 km2減少到2015年的1 506.3 km2,28年來總退縮率為27.3%,年均退縮率為0.98%;冰川存在一定的地形/溫度分布差異,海拔在4 900~5 100 m,坡度為10°~20°,坡向以北和東北方向為主,夏季氣溫為3~5 ℃時,是冰川發育的聚集區;冰川退縮也存在一定的地形/溫度分布差異,海拔4 200~4 300 m,坡度10°~20°,坡向南和東南方向,夏季氣溫小于2 ℃,是冰川退縮最快的區間。以溫度為主導的模擬研究表明,研究區冰川未來15和30年退縮嚴重,退縮率分別達到10.9%和33.5%。
關鍵詞祁連山;冰川;遙感;地理加權回歸
中圖分類號P343.6文獻標識碼A文章編號0517-6611(2017)30-0059-05
AbstractGlacier in the Qilian Mountains during the past 28 years were interpreted based on Landsat TM(1987) and OLI(2015) data. The coupling relationship between glacier retreat and influence factors were discussed. The results showed that the glaciers decreased in this area by 27.3% between 1987(2 072.7 km2) and 2015(1 506.3 km2), and the annual percentage of area changes for the glacier was 0.98%. The best condition of altitude for glacier ranged from 4 900 to 5 100 m, slope being 10°-20°, north and northeast slope and summer temperature 3-5 ℃. The glacier retreat occured mainly at altitude ranged from 4 200 to 4 300 m, slope being 10°-20°, south and southeast slope and summer temperature less than 2 ℃. The results of the simulation study showed that the glaciers decreased in this area next 15 or 30 years was up to 10.9% and 33.5% respectively.
Key wordsQilian Mountains;Glacier;Remote sensing;Geographical weighted regression
冰川是氣候系統的產物,在諸多環境系統中,受氣候變化影響最直接,對全球變暖指示性最敏感,被認為是氣候系統多圈層相互作用的關鍵紐帶[1]。冰川變化可以通過野外站點觀測,由于中低緯度冰川都在高海拔、復雜地形區域,惡劣環境制約著實地觀測,長期定點觀測的冰川并不多。受制于較少的實地觀測點,監測數據不足以反映整個區域尺度變化,以點代面的研究忽視了各種變量空間異質性。以遙感和地理信息系統為手段的研究能夠滿足山地冰川變化監測要求。
隨全球變暖,冰川普遍出現退縮,表現為末端后退、平衡線升高、面積變小,這在全球或較大尺度上得以廣泛認同[2-3],但受區域地形和氣候的影響,不同地區的冰川變化有較大差異。……