文中所指的一江四河是指雅鲁藏布江及年楚河、拉萨河、雅砻河、尼洋河四条主要支流。
Here , Brahmaputra River and its four branches , that is to say , Brahmaputra and its four branches of Nian-chu River , Lhasa River , Ya-long River and Ni-yang River .
雅砻河