Amu Darya
The long Amu Darya originates in the glaciers of the Pamir Mountains in the northeast. Some 965 km of its upper course constitutes Afghanistan's border with Turkmenistan, Uzbekistan and Tajikistan. Flowing in rapid torrents in its upper course, the Amu Darya becomes calmer below the mouth of the Kokcha, west of Fayzabad. The Kunduz River is another major tributary. During its flood period the upper course of the Amu Darya, swollen by snow and melting ice, carries along much gravel and large boulders.