The Indus River is the longest river in Pakistan and the third largest river, in terms of annual flow, on the Indian Subcontinent. It is often considered the life-line of Pakistan by the people of that country. The Europeans used the name "India" for the entire Indian Subcontinent based on Indos, the Greek appellation of this river. Originating in the Tibetan plateau in the vicinity of Lake Mansarovar, the river runs a course through Ladakh district of the state of Jammu and Kashmir in India and the Northern Areas (Gilgit-Baltistan), flowing through the North in a southerly direction along the entire length of the country, to merge into the Arabian Sea near Pakistan's port city of Karachi. The total length of the river is 3,180 kilometres (1,976 miles). The river has a total drainage area exceeding 1,165,000 square kilometres (450,000 square miles). The river's estimated annual flow stands at around 207 cubic kilometres. Beginning at the heights of the world with glaciers, the river feeds the ecosystem of temperate forests, plains and arid countryside. Together with the rivers Chenab, Ravi, Sutlej, Jhelum, Beas and the extinct Sarasvati River, the Indus forms the Sapta Sindhu (Seven Rivers) delta in the Sindh province of Pakistan.

The ultimate source of the Indus is in Tibet; it begins at the confluence of the Sengge and Gar rivers that drain the Nganglong Kangri and Gangdise Shan mountain ranges. The Indus then flows northwest through Ladakh and Baltistan into Gilgit, just south of the Karakoram range. The Shyok River, Shigar and Gilgit streams carry glacial waters into the main river. It gradually bends to the south, coming out of the hills between Peshawar and Rawalpindi. The Indus passes gigantic gorges 4,500-5,200 metres (15,000-17,000 feet) high near the Nanga Parbat massif. It flows swiftly across Hazara, and is dammed at the Tarbela Reservoir. The Kabul River joins it near Attock. The remainder of its route to the sea is in plains of the Punjab and Sindh, and the river becomes slow-flowing and highly braided. It is joined by Panjnad River at Mithankot. Beyond this confluence, the river, at one time, was named Satnad River (Sat = seven, Nadi = river), as the river was now carrying the waters of the Kabul River, the Indus River and the five Punjab rivers. Passing by Jamshoro, it ends in a large delta to the east of Thatta.

The Indus is one of the few rivers in the world that exhibit a tidal bore. The Indus system is largely fed by the snows and glaciers of the Himalayas, Karakoram and the Hindu Kush ranges of Tibet, the state of Jammu and Kashmir in India and the Northern Areas of Pakistan. The flow of the river is also determined by the seasons - it diminishes greatly in the winter, while flooding its banks in the monsoon months from July to September. There is also evidence of a steady shift in the course of the river since prehistoric times - it deviated westwards from flowing into the Rann of Kutch.

credited to wikipedia and flickr: Michael Foley Photography