Exploring Earth From Space: Lake Balkhash – The Largest Lake in Central Asia

Lake Balkhash, the largest lake in Central Asia, is featured in this false-color image captured on November 29, 2021, by the Copernicus Sentinel-2 mission. Credit: Contains modified Copernicus Sentinel data (2021), processed by ESA, CC BY-SA 3.0 IGO

Lake Balkhash, the largest lake in Central Asia, is featured in this false-color satellite image captured by the Copernicus Sentinel-2 mission.

The lake, which is situated in east-central Kazakhastan, is around 605 km (376 miles) in length from east to west, with a maximum depth of around 25 m (82 feet). The lake’s size varies depending on water balance, with its area fluctuating from around 15,000 sq km to 19,000 sq km (5,800 sq miles to 7,300 sq miles).

Jutting out into the lake is the Sarymsek Peninsula which divides Balkhash into two separate hydraulic parts. The west part is wide and shallow with its water on this side particularly fresh and suitable for drinking. The east part, on the other hand, is narrow and relatively deep, with its waters on this side of the basin brackish and salty. The two parts of the lake are united by a narrow strait, the Uzynaral visible in the center of the image, with a depth of around 6 m (20 feet).

The sediment plume passing through the Uzynaral Strait is most likely due to waves stirring up sediments from the bottom of the lake. This has led to a higher reflection and thus a brighter water color in this part of the lake.

The north banks of Lake Balkhash are high and rocky while the south banks are low and sandy, with wide belts covered with thickets of reeds and numerous small lakes. The waters of the lake periodically flood these low-lying banks.

A high presence of sea ice can be seen in bright blue-greenish colors especially near the southern shoreline. This color is due to ice having a higher reflectance in the visible parts of the spectrum than in the near-infrared. Balkhash usually remains frozen from the end of November to the beginning of April, with this image captured on November 29, 2021.

South of Balkhash lies the Saryesik-Atyrau Desert, which stretches for around 400 km (250 miles) in east Kazakhastan. There are a great number of small lakes, ponds, and wetlands in the desert (visible in brown), as well as occasional grasslands, that support a varied animal and bird population.

Sentinel-2 is a two-satellite mission to supply the coverage and data delivery needed for Europe’s Copernicus program. The mission’s frequent revisits over the same area and high spatial resolution allow changes in water bodies to be closely monitored.

This image is also featured on the Earth From Space video program embedded above.