Zeravshan River
Valley of Zeravshan in Tajikistan
Course of Zeravshan
The Zeravshan ( Uzbekistan Zarafshan, German also Zeravshan, Sarafschan, Serefschan, Sarefschan ( " Gold Donors " ) by russian Зеравшан; anglicised also Zeravschan or Zarafshan, in the upper reaches Матча ) is the third largest river in Uzbekistan. It rises in Tajikistan to 2,750 m above sea level at the Serafschangletscher in Koksugebirge. The river is 781 km long and the catchment area of 4000 km ² in size, according to other sources 877 km or 17.7 thousand km ². According to other data ( Meyers encyclopedia 5th edition ) of the river is 644 ( Brockhaus 1911) and 886 km long. At its source, the river Mostchokh Darya is called. Only further downstream the name to Zeravshan changes after he has recorded several tributaries.
The first 300 km of the river lays back in Tajikistan. It flows between the steeply sloping to him Turkestan Mountains in the north and the Serafschankette in the south to Fort Pendschakent westward in a narrow valley, which begins to expand by Firman from Tepa. Then he enters the Zeravshan Valley, which lies in the region of Samarkand in Uzbekistan. There he assumes northwestern direction is east of Samarkand in the valley Miankal in the mountains Tschoponaiy divided by a causeway artificial irrigation in two arms, the Akdarja ( " White River " ) and Karadarja ( " Black River "), which in itself Chatyrtschi ( Yangirabad ) reunite.
Overall, the Zeravshan has 70 tributaries. Some of them do not reach him due to lack of water at times. The Zeravshan is connected to the Amu Darya with an irrigation channel. The river seeps 20 km behind the connection to the Amu Darya south-west from Bukhara in the desert in the salt marsh Karakol ( Karagöl ), without having reached the Amu Darya.
At the point of entry from Tajikistan to Uzbekistan, the annual runoff 5.3 km ³ ( billion cubic meters ). Further downstream of the outflow is only growing at 5.5 km ³. Tajikistan currently consumes only 0.3 km ³, or about 6-8 % of the flow. The remaining water is consumed in Uzbekistan.
On Zeravshan there are a number of dams and reservoirs: Pervomai, Akdarin, Damkhodzhin, Narpai, Karmarin, Shafrikan, Kharkhur, Babkent, and many large and medium-sized channels for irrigation and water supply. In the middle reaches of the reservoirs are Tudakul ( 17,500 or 22,000 ha), Kuyumazar (1600 ha) and Shurkul (1600 ha). There are also several reservoirs that contain very salty water. Four lakes receive water from drainage channels: Dengizkul ( 25,000 ha), Karakyr ( 12,000 ha), Tuzgan ( 5700 ha) and Shurgak (1600 ha). In the regions of Samarkand and Navoi the water to irrigate 530,000 acres of land is needed on the main agricultural products are grown, serving the needs of the rapidly growing rural population. In 1900, irrigated 126 channels 7143 km ² ( according to Meyer).
The water quality has deteriorated due to the influence of the returning of the irrigation water and the sewage of cities such as Samarkand, Navoi and Kattakurgan. The salt content is increased from 0.27 g / l at its source to to 2.4 g / l at its mouth. Most of the river is dirty underneath the cities Kattakurgan and Navoi.