The river was traditionally known to the Western world from Greek and Roman times as the Oxus and was ....

The precipitation falls mainly as snow during the winter and helps feed the glaciers in the source areas of the Amu Darya, at the highest altitudes in the Pamirs and the Hindu Kush, where temperatures average below freezing in winter and annual precipitation may exceed 40 inches (1,015 mm). In the lower reaches of the Amu Darya, mean annual precipitation is less than 4 inches (100 mm), with mean July temperatures above 77 F (25 C) and mean January temperatures ranging between 32 F and 50 F (0 C and 10 C). The river's two principal sources, the Vakhsh River and the Panj River, whose tributaries include the Pamir, follow a westerly course. The Amu Darya's flow increases from March to May, when snow melts on the plains and rainfall increases, and the flow is further augmented in summer as the ice and snow of the mountain ranges melt. The river carries the name Amu Darya only below the confluence of the Panj with the Vakhsh. The Amu Darya loses much of its water in this region t! o irrigation, evaporation, and seepage. However, the Soviet government began diverting massive amounts of water from the river beginning in the 1950s to irrigate cotton and other crops grown in the river's lower basin. The diversion of water from the Amu Darya for irrigation decreased the amount of water entering the Aral Sea, which consequently began shrinking. Surface runoff has transported these salts into surface waters and increased the salinity of the Amu Darya. Lakes and bogs dried up in the former Amu Darya delta, now far from the sea's shores, and the wetlands fed by the river shrank to only a tiny percentage of their former size. The depleted and polluted waters of the lower Amu Darya and its former delta, once rich with wildlife, are now nearly devoid of fish and birds.