Afghanistan's geography: rivers that rise in the Hindu Kush and end inland

How the Hindu Kush divides the country

Britannica compares the shape of Afghanistan to a leaf, with the Wakhan Corridor, high in the Pamirs, as its stem. The Hindu Kush and its branches give the country its tilt from north-east to south-west. About 160 kilometres north of Kabul the main range spreads out westward as the Baba, the Bayan, the Sefid Kuh and other ranges, and each of those throws spurs in different directions. Noshaq, on the Hindu Kush, rises to 7,492 metres; the highest of the southwestern ranges is Shah Foladi in the Baba Mountains, at 5,142 metres.

The range divides Afghanistan into three regions of very unequal size.

The passes decide how the country is crossed. The Shebar Pass, northwest of Kabul, sits where the Baba Mountains branch off the Hindu Kush; the Salang and Kushan passes cut through the main range; the Khyber, on the Pakistan border southeast of Kabul, leads down to the Indian subcontinent. Its summit, at 1,070 metres, is in Pakistan at Landi Kotal, 5 kilometres east of the border town of Torkham. Further south the road from Kandahar crosses at Spin Boldak toward Quetta over flat, dry ground, although on the Pakistani side it has to climb the Khojak Pass at 2,707 metres.

Most of the country lies between 600 and 3,000 metres. The Sistan depression in the far southwest falls to about 450 to 500 metres.

The northeast is seismically active, and Britannica puts about 50 earthquakes a year in Afghanistan, many of them with epicentres in Badakhshan. A magnitude 5.9 earthquake near the Pakistan border in June 2022 killed at least 1,150 people, and one of magnitude 6.3 northwest of Herat on 7 October 2023 killed more than 1,400.

Where the four river systems end

Four systems carry most of the water: the Amu Darya, the Harirud, the Helmand and the Kabul. Of these only the Kabul River reaches an ocean, flowing east from the Paghman range to join the Indus in Pakistan. The others begin in the central highlands and finish in closed basins.

The Amu Darya, the Oxus of the classical writers, is 2,540 kilometres long. It rises in the glaciers of the Pamirs, drains about 241,000 square kilometres of the north and northeast, and forms the frontier with Tajikistan and Uzbekistan for about 1,000 kilometres of its upper course. Two of its Afghan tributaries, the Kowkcheh and the Qonduz, come down from the mountains of Badakhshan and Kondoz, and boats can use the river from the Kowkcheh confluence, 100 kilometres west of Feyzabad.

None of these rivers runs evenly. Britannica describes the flow of the streams as torrential in spring, when the mountain snow melts, and negligible in summer, which is why dams and reservoirs have to be built far up in remote valleys and why hydroelectric power has been developed on any scale only around Kabul and Jalalabad.

The Harirud rises on the western slopes of the Baba Mountains at 2,750 metres and runs west across the broad Herat valley. After watering it the river turns north about 130 kilometres beyond the city, forms 105 kilometres of the border with Iran, crosses into Turkmenistan and disappears in the Karakum Desert. Its eastern reaches, rapids included, freeze hard enough in winter for people to travel along the ice as on a road.

The Helmand rises in the Baba Mountains about 80 kilometres west of Kabul and runs some 1,150 kilometres. With the Arghandab and its other tributaries it drains more than 259,000 square kilometres, crosses the Margow Desert and ends in saline seasonal lakes in the Sistan depression on the Iranian border.

Lakes of any size are few. The Saberi in the southwest is a salt flat that is sometimes flooded, and Istadeh-ye Moqor, 100 kilometres south of Ghazni, is saline. The five Amir lakes of the Baba Mountains, Band-e Amir, are coloured from milky white to dark green by the rock beneath them. Snow falls from November to March and melts into all of these systems, yet about two-thirds of the country's water leaves it for Pakistan, Iran and the three Central Asian neighbours.

Why only the eastern mountains catch the monsoon

The mountains on the eastern frontier stand between the interior and the moist winds of the Indian Ocean, and Britannica gives that as the reason the climate is dry. Only the ranges along the Pakistan border catch the Indian monsoon, usually between July and September, and the Suliman Mountains mark its western limit. Elsewhere most precipitation falls from December to April: snow in the highlands from December to March, intermittent rain in the lowlands.

The Salang Pass of the Hindu Kush has recorded 1,350 millimetres in a year and the Farah region in the west about 75. In the mountains the mean rises from west to east to about 400 millimetres.

Temperature follows height and distance from the mountains. Jalalabad has recorded 49 °C in July. Kabul, at 1,800 metres, has recorded −31 °C, and in the Wakhan and the glaciated northeast the January mean falls below −15 °C. The southwest has strong winds almost daily in summer, and at Herat the wind blows hard from the northwest from May to September.

Herat's winters are mild: in three years out of four it does not freeze hard enough for people there to store ice. The same district is where Ahmad Shah's army, retreating from Persia in 1750, is said to have lost 18,000 men to cold in a single night. From May to November the difference between day and night temperatures exceeds 17 °C.

Drought is the recurring hazard. A drought in 2000 killed some four-fifths of the livestock in the south, by Britannica's account, and the Wikipedia country article records severe drought in 25 of the 34 provinces. Almost 14% of the country's glacier cover was lost between 1990 and 2015, and mapped snow cover fell from 9,496 square kilometres in 2000 to 7,485 in 2018. The same article cites a projection that climate change could displace another 5 million people inside the country by 2050.

What the land is used for

Very little of it is farmed: only about one-eighth of the land is arable, only about half of that is cultivated in a given year, and about half of the cultivated land is irrigated because the rest of the country is too dry to rely on rain. A land cover survey counted rangeland on 44.58% of the country in 2018, down from 47.97% in 2000; barren land, mostly in the centre and south, on 34.82%; and irrigated farmland on 3.30%, up from 2.81% in 2000.

The soils follow the regions. The northern plains have deep, fertile, loess-like soils and are intensively cultivated and densely settled. The central highlands have steppe and meadow soils and visible erosion. The southwestern plateau is infertile desert except along the rivers, where alluvium has been laid down, and the oasis around Kandahar sits near the Arghandab.

That southern desert has been pushed back by pumps. Cheap diesel water pumps from China and Pakistan and, in the 2010s, cheap solar power allowed farming and settlement to spread into the deserts of Kandahar, Helmand and Nimruz, and wells there have been deepened as the water table has been drawn down. Much of that new land grew opium poppy.

Forest covered about 1,208,440 hectares in 2020, roughly 2% of the land, a figure the Wikipedia country article records as unchanged since 1990; Britannica gives about 3%. The woods lie mainly in the east and on the southern slopes of the Hindu Kush, with fir above about 3,000 metres, cedar between 1,700 and 2,200, and oak, walnut, alder, ash and juniper below. Pistachio grows north of the Hindu Kush.

Who lives on each side of the range

Settlement follows the water around the rim of the highlands. Kabul, Kandahar in the south, Herat in the west, Mazar-e Sharif and Kunduz in the north and Jalalabad in the east form a ring, and Highway 1, the Ring Road, joins them over 2,210 kilometres while skirting the mountains. The Salang Tunnel, completed in 1964, carries the road through the Hindu Kush and links the north to the south.

Britannica maps the peoples onto the land in the same pattern. In the northeast, the Badakhshan and Wakhan region of mountains and high plateaus, most people are Tajik farmers and artisans, with a few Kyrgyz herders in the Wakhan. The lower plains to the west are shared by Uzbek farmers and Turkmen who were traditionally semi-nomadic herders. South of the range, the Kabul region is the corridor between the others; the Durrani Pashtun live around Kandahar and the Ghilzai between Kandahar and Kabul; Herat mixes Tajiks, Pashtuns and Chahar Aimak. The Hazara live in the Hazarajat, the high centre, which Britannica describes as the most isolated part of the country because of its mountains and poor communications.

No full census has been taken since a partial count in 1979, so the number and spread of people are estimates. The National Statistics and Information Authority put the population at 35.7 million in 2024; the UN estimate is above 42 million.

Which borders were drawn from outside

Afghanistan has no coast; the nearest sea is the Arabian Sea, about 480 kilometres to the south. Its six land borders total 5,987 kilometres by the figures in Wikipedia's geography article.

The lines were fixed in the late 19th century by Britain and Russia, and the Wakhan Corridor exists because they wanted a buffer between their empires. The border with Pakistan is the Durand Line, agreed on 12 November 1893. Its length varies by source: 2,670 kilometres in that geography article, 2,640 in the Wikipedia article on the line, and 2,310 on the home page of the Afghan Geodesy and Cartography Head Office, which marks it as an international boundary. The line is recognised internationally as Pakistan's western border and remains largely unrecognised in Afghanistan. India claims a border with Afghanistan through the part of Kashmir that Pakistan administers. This catalogue records both disputes and takes no position on either.

What lives in the mountains and the deserts

Large mammals were once plentiful and are now far fewer, and the tiger has gone. Snow leopards and brown bears live in the high alpine zone. The Wikipedia country article places Marco Polo sheep only in the Wakhan, and the markhor, a wild goat with long twisted horns, and the ibex are found in the Pamirs. Wolves, foxes, striped hyenas and jackals range across the mountains and foothills, and gazelles live on the steppe of the south and west.

About 460 bird species have been recorded, 235 of which breed in the country, and migratory birds are numerous in spring and autumn. The rivers on the northern slopes of the Hindu Kush hold brown trout. The Afghan hound, a long-haired running dog, comes from the country and was used to hunt wolves. Several animals are found nowhere else, among them the Afghan flying squirrel, the Afghan snowfinch and the Paghman mountain salamander.

Three national parks are designated: Band-e Amir, Wakhan and Nuristan. Band-e Amir has been on UNESCO's tentative World Heritage list since 2004.