藏羚羊在可可西里地区的青藏铁路旁觅食（3月11日摄）。青藏铁路穿越可可西里全境，是藏羚羊迁徙的必经之地。为方便野生动物，铁路通过架设高桥的方式在这里设置了33处、总长超过58公里的通道。被称为“高原净土”的青藏高原是长江、黄河、澜沧江等5大水系的发源地，也是亚洲重要的水源涵养地和气候启动区。青藏铁路通车10年来，一直采用我国业界最严格的环保标准运营。新华社记者 吴刚 摄
Tibetan antelopes graze near the Qinghai-Tibet railway in Hoh Xil, northwest China's Qinghai Province, March 11, 2016. The 1,956-kilometer-long Qinghai-Tibet railway, the world's highest altitude train line, has been put into service for 10 years. It links Lhasa, capital of southwest China's Tibet Autonomous Region, and Xining, capital of Qinghai Province in northwest China. [Photo: Xinhua]