Uzbekistan’s climate, inland waters, soils and vegetation are closely linked: a dry climate → little rain → rivers fed in the mountains → irrigated farming → oases. Understand this chain and most questions on the topic solve themselves. The topic is also practical: wise use of water, the placing of crops and the fight against salinisation all rest on this knowledge. Exams ask about climate figures and their causes, rivers, canals, reservoirs, soils and vegetation belts.
§1. Climate-forming factors
Position — Uzbekistan lies in the south of the temperate belt, roughly between 37° and 46° N. Sunshine is abundant (about 2,800–3,000 hours a year) and the summer Sun stands high, so heat is plentiful.
Distance from the oceans — dry air, few clouds, a large temperature range.
Relief — open plains in the north and west let cold Arctic air in freely in winter. The south-eastern mountains catch moist air from the west, raise rainfall on their slopes and shelter the southern valleys from cold.
Air masses — temperate and Arctic air in winter; tropical continental air in summer (formed over Central Asia’s scorching deserts).
The surface — sand and clay heated in summer warm the air even more.
§2. Climate figures
The climate is extremely continental and dry: long, very hot summers; short winters with frosty spells
July is the warmest month; in the south the mean exceeds +30 °C, and the maximum can exceed +45 °C (the Termez area is one of the hottest places).
January is the coldest month; in the north (Ustyurt) the mean is below zero and frosts can fall below −30 °C; in the south (Surkhandarya) January is above zero.
Precipitation: about 80–200 mm on the plains, 300–400 mm at the foot of the mountains, 600–900 mm or more on western mountain slopes. It falls mainly in winter and spring; summer is almost rainless.
Potential evaporation is many times greater than precipitation, so farming is impossible without irrigation.
The growing season is long: heat-loving crops (cotton, rice, grapes) are grown, and subtropical crops in the south.
Winds: the garmsil (hot, dry, it scorches crops), the Kokand and Bekabad winds (at the entrance and exit of the Fergana Valley) and the "Afghan" wind (dust storms in the south).
Seasons. Spring comes early and is changeable: warm days alternate with cold snaps, downpours and hail — it is the wettest period. Summer is long, cloudless and scorching. Autumn is dry, warm and long, good for harvesting cotton and fruit. Winter is short and unsettled: mild days alternate with cold air from the north, and snow does not lie long on the plains.
Worked example
City A: January −8 °C, July +26 °C. City B: January +3 °C, July +31 °C. Which is more continental?
Range A: 26 − (−8) = 34 °C.
Range B: 31 − 3 = 28 °C.
The city with the larger range is more continental.
Answer: A — probably located in the north on an open plain.
Worked example
A desert area gets about 150 mm of precipitation a year, with potential evaporation of about 1,500 mm. How many times greater is evaporation, and what does it mean?
Ratio: 1,500 / 150 = 10.
Moisture coefficient: 150 / 1,500 = 0.1 — very low.
Answer: 10 times; moisture is severely lacking, so farming needs irrigation.
§3. Rivers
Uzbekistan’s rivers have inland drainage: they never reach the ocean and belong to the Aral basin. Most rise in the mountains of neighbouring countries (transboundary rivers) and are fed by snow and glaciers, so high water comes in summer, the irrigation season.
The Amu Darya forms where the Panj and the Vakhsh join; it has the greatest flow in Central Asia and in its lower course irrigates the Khorezm and Karakalpak oases.
The Syr Darya forms where the Naryn and the Kara Darya meet (in the Fergana Valley); it is the longest river.
The Zarafshan rises from the Matcha (Zarafshan) Glacier; it irrigates the Samarkand and Bukhara oases and no longer reaches the Amu Darya.
The Chirchik (formed by the Chatkal and the Pskem), the Akhangaran, the Kashkadarya, the Surkhandarya and the Sherabad.
The upper courses of mountain rivers are fast and rich in energy, so hydroelectric stations are built (the cascade on the Chirchik).
§4. Canals, reservoirs and lakes
Canals: the Great Fergana, North Fergana, South Mirzachul (Golodnaya Steppe), Karshi Main and Amu-Bukhara canals. They carry river water into deserts and steppes and made it possible to bring new land into use.
Reservoirs: Charvak (Chirchik), Tuyamuyun (Amu Darya), Kattakurgan, Tudakul, Andijan, Talimarjan, Chimkurgan. They store winter and spring water, release it in summer for irrigation and generate electricity.
Lakes: the Aydar-Arnasay system (formed from surplus water discharged from the Syr Darya), Sudochye; the Aral Sea.
Groundwater, mineral and thermal springs (Tashkent, Chartak) are used at health resorts.
§5. Soils
Plains: sandy, takyr, solonchak (salt) and desert-sandy soils; foothills — serozem (grey soil); mountains — brown and mountain-meadow soils
Soils also change with height. Serozem is the main soil of the adyr foothills; it is poor in humus but fertile when irrigated. Irrigated serozems and meadow soils are the main farmland. Salinisation is the biggest problem: over-irrigation raises the water table, the water evaporates and leaves salt at the surface. Remedies are collector-drainage networks, leaching saline land and water-saving (drip) irrigation.
§6. Vegetation and altitudinal belts
Vegetation changes from bottom to top with relief and climate:
yaylov — subalpine and alpine meadows, summer pastures;
above — snow and glaciers.
Riverside tugai forests (Euphrates poplar, oleaster, tamarisk) grow along rivers. Nature reserves and national parks protect valuable plants and animals.
Worked example
On a field trip you see red and yellow tulips, snowdrops, rhubarb, ferula, and barberry and dog-rose shrubs. Which belt is it?
Ephemerals and scattered shrubs are typical of low hills at the foot of the mountains.
There is no juniper or forest, so it lies below the mountain belt.
Answer: the adyr belt.
§7. Climate, water and the economy
Climate shapes the economy. Heat is plentiful but moisture is scarce, so irrigated farming dominates in Uzbekistan: cotton, grain, vegetables, orchards and vineyards are concentrated in oases. Rain-fed (lalmi) land is found only in the foothills, where more rain falls. Desert pastures are used for karakul sheep and camels. Much of the water comes from neighbouring countries, so saving water and international co-operation matter greatly. As the climate warms, mountain glaciers are shrinking, which may reduce river flow in future. That is why drip irrigation, concrete-lined canals, less thirsty crops and solar power are being expanded.
Check yourself
When does most precipitation fall in Uzbekistan?
What is the garmsil?
Where does the Zarafshan rise?
On which river is the Charvak Reservoir?
What is the soil of the adyr belt?
January −5 °C, July +29 °C. Range?
Precipitation 200 mm, potential evaporation 1,600 mm. Moisture coefficient?
Which rivers join to form the Chirchik?
Common mistakes
Writing that most rain falls in summer — summer is almost dry.
Calling the Zarafshan a tributary of the Amu Darya — it no longer reaches it.
Ignoring the minus sign when computing the range.
Treating salinisation as purely natural — often poor irrigation is to blame.
Mixing up how the rivers form: Naryn + Kara Darya = Syr Darya; Panj + Vakhsh = Amu Darya.