Lake Dengizkul

Dengizkul — a lake in Olot district of Bukhara region. In the Middle Ages it was called “Borgini farox”, i.e., “Great lake”. In 10th‑century written sources Dengizkul was named “Qorakul”, “Bukhara’i Somjan” (“Lake Somjan”). On a 10th‑century map of Central Asia drawn by the Arab geographer Ibn Hawqal it is shown under the name “Baxr al‑Bukhara” (“Bukhara Sea”). Muhammad Narshakhi (10th century) wrote about this lake: “its width is twenty farsak (140–160 km), the excess water of the Bukhara River collects in this lake, it has many aquatic animals, and throughout Khurasan no place has as many birds and fish as here.”

The lake is located in a tectonic basin on the southern edge of the province (in the lower course of the Zarafshon River) at an altitude of 181.5 m above sea level. It is filled by seepage water formed as a result of irrigation of agricultural fields with runoff water from several collector‑drains that flow into the lake. The main branch of the Zarafshon River—Toyqir—also reaches the lake during the flood period. Water does not flow out of the lake; loss occurs mainly by evaporation and partly by infiltration. In the 1960s and early 1970s the area and depth of the lake changed frequently: in periods of abundant inflow the lake’s area was 80–100 km², depth 1.0–1.5 m, while at the end of summer it was respectively 40–60 km² and 25–30 cm. In the 1970s‑80s, due to the reclamation of new lands in the south of Bukhara Province and an increase in runoff water, the lake expanded year after year. By the end of the 1980s (1987) its length was 43.3 km, its widest point 9 km, its deepest point 22 m, water surface area 267 km², water volume 2.7 km³. These values vary throughout the year in accordance with water‑level fluctuations: in autumn, when evaporation decreases, the water balance stabilizes, then the water level rises again. The lake is fed by collector‑drain waters. Evaporation is considerably strong in summer. Waves are observed on the lake under wind influence. The water is very salty; in some places the lake bottom is covered with a layer of salt up to 0.5 m thick. The lake water is medicinal.

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