The Aral Sea is a saltwater lake between Kazakhstan and Uzbekistan in Central Asia. It was the fourth-largest lake in the world. The lake water is mainly supplemented by the Amu Darya and the Syr Darya, but now the Amu Darya almost does not flow into the Aral Sea.
The Aral Sea was once famous for its clear water and good water quality, and it was also called "the sea of islands" because of its more than 1,500 islands. The basin of the Aral Sea once included all of Uzbekistan and parts of Tajikistan, Turkmenistan, Kyrgyzstan, Kazakhstan, Afghanistan, and Iran.
However, due to the water diversion for irrigation and the project to change the river course by the Soviet Union after the 1960s, the Aral Sea has been shrinking, and the salt content has increased. By 1997, it had dropped to 10% of its original size and was divided into four lakes: the North Aral Sea, the South Aral Sea becomes, two basin lakes, and a smaller lake in the center.
Aral Sea Introduction
Since the second half of the 20th century, after the construction of the Karakum Canal in Turkmenistan, the amount of water entering the Aral Sea has been reduced to 7 billion cubic meters. The area of the Aral Sea has shrunk by half, its salinity has tripled, coastal marshes have shrunk, and a lot of shrubs have disappeared. The Syr Darya bird species decreased by 135, and the Aral Sea fish species decreased from 24 to 4 species.
As the water level continued to decline, the Aral Sea was divided into two water bodies in 1987: the South Aral Sea and the North Aral Sea; and the Karakum Canal, completed in 1988, transported 12.9 million cubic meters of water (equivalent to 15% of the total flow of the Amu Darya River), the South Aral Sea was further divided into east and west in 2003. By 2014, most of the South Aral Sea had dried up and disappeared, but the area of the North Aral Sea had recovered. Satellite images taken by NASA in 2014 showed the first complete depletion of the southeastern Aral Sea basin in modern history, creating a basin known as the Alarkum Desert.
The Aral Sea was formed at the end of the Pliocene (7 million to 2.5 million years ago) when the earth's crust subsided, and the surface water was trapped, which is the remains of transgression. Since the Pleistocene (2.5 million to 10,000 years ago), the waters of the Syr Darya and the Amu Darya have been injected into the Aral Sea so that the water level often remains unchanged. The coastline has marine and continental sediments, and the lake bottom is flat and sloping from east to west.
Aral Sea Size
The Aral Sea is 53 meters above sea level. When the lake is at its maximum, it is 435 kilometers long from north to south, 290 kilometers from east to west, covers an area of 68,000 square kilometers, and has an average depth of 16 meters. The deepest point outside the west coast is 69 meters. It was the fourth-largest lake in the world. Its tributary delta has dozens of small lakes and 550,000 hectares of ecologically rich swamps and wetlands.
Climate and Hydrology
The Aral Sea area has an extreme continental climate. The lake water level has changed significantly due to the periodic drought. The annual rainfall is 100 mm. The water temperature in July is 23~25°C (73~77°F); in November~December, the water temperature is -0.7°C (30.8°F), and the lake is frozen. The lake has been navigable for seven months. The evaporation of the lake is roughly the same as the inflow, but over a long time, the water level has gradually decreased.
Kazakhstan made a last effort to save the Aral Sea. They built a dam between the North and South Aral Seas to protect the North Aral Sea, but the dam was equivalent to sentencing the southern Aral Sea to death. The shrinking of the Aral Sea has been called "one of the worst environmental disasters on Earth." The once-thriving fishing industry in the region has been destroyed, causing unemployment and economic hardship. The Aral Sea region is heavily polluted, resulting in serious public health problems and animal and plant extinction.