Helmand River and Lake Hamun, Afghanistan and Iran31.0N 61.2E
Much of the land here in Iran (left), Pakistan (bottom right) and Afghanistan (top right) appears quite dry, with a large area of sandy desert in Afghanistan near its southern border with Pakistan.
However, the Helmand River, which appears white due to sun glint, flows through this desert region. Stretching for 1,150 km (715 miles), it is the longest river in Afghanistan and the primarily watershed for the endorheic Sistan Basin.
It rises in the Hindu Kush mountains and crosses south-west through the desert of Dashti Margo, to the Seistan Marshes and the Hamun-i-Helmand lake region around Zabol at the Afghan-Iranian border.
The river remains relatively salt-free for much of its length, unlike most rivers with no outlet to the sea. This river is used extensively for irrigation, although a buildup of mineral salts has decreased its usefulness in watering crops.
Its waters are essential for farmers in Afghanistan, but it feeds into Lake Hamun, visible above the image center, and is also important to farmers in Iran’s southeastern Sistan and Baluchistan province. Lake Hamun has an area of 1,600 km² at its greatest extent during the rainy season.