South Tibet
In Tibet the river flows through the South Tibet Valley, which is approximately long and wide. The valley descends from above sea level to . As it descends, the surrounding vegetation changes from cold desert to arid steppe to deciduous scrub vegetation. It ultimately changes into a conifer and rhododendron forest. The tree line is approximately . Sedimentary sandstone rocks found near the Tibetan capital of Lhasa contain grains of magnetic minerals that record the Earth's alternating magnetic field current.