恢復北鹹海生態的哈薩克奇蹟

Water is returning to the North Aral Sea in Central Asia that had shrunk to a quarter of its former size during the last half of the 20th century. Fish, sea birds and reptiles have begun to repopulate the Aral Sea and surrounding area.

Although the seashore is shared by only two countries, Kazakhstan in the north and Uzbekistan in the south, the Aral Sea Basin is fed by two large rivers, which run through the mountainous countries of Afghanistan, Tajikistan and the Kyrgyz Republic and through the plains of Uzbekistan, Kazakhstan and Turkmenistan.

The Aral Sea began to shrink in the 1960s, when massive diversion of water for cotton and rice cultivation under the Soviet Union drained the two rivers that feed the sea, the Syr Darya and Amu Darya. The resulting three-quarters decrease in volume of the Northern Aral Sea by 1996 devastated the surrounding environment and ruined the traditional fishing economy of the bordering villages.

This week the government of Kazakhstan announced that its US$260 million rescue program for the Northern Aral Sea is working. Launched in 2001 by Kazakhstan President Nursultan Nazarbayev and supported by the World Bank, the program has increased the North Aral Sea's surface by about 30 percent since the last assessment was conducted in 2003, according to a statement Wednesday by the Kazakh Foreign Ministry.

The North Aral Sea's surface increased from 2,550 square kilometers (985 square miles) in 2003, the ministry said, to 3,300 square kilometers (1,275 square miles) in 2008.

And the sea's depth increased from 30 meters (98 feet) in 2003 to 42 meters (138 feet) in 2008.

To increase the volume of water being discharged into the northern part of the sea, the US$85.8 million Kok-Aral Dam was built jointly by the Government of Kazakhstan and the World Bank, with the bank providing a loan of US$65 million.

The 13 kilometer (8 mile) long dam separating the smaller North Aral Sea from its larger, saltier and more polluted southern part was completed in August 2005. Since completing the dam, Kazakhstan has been able to keep the water from the Syr Darya River in the North Aral Sea. Newly reconstructed, rebuilt, and rehabilitated waterworks along the Syr Darya are increasing the carrying capacity of the river, filling the Northern Aral Sea and benefiting farmers by irrigating their lands.

With the water level now higher in the northern part of the sea, a sluice can begin operating to allow excess water to flow into the parched South Aral Sea.

In the recent past only one species of fish remained in the North Aral Sea. Today, 15 different species have been recorded - bringing back work and income to about 100 local fishermen.

Even the local climate has improved since the dam was completed. As the lake dried up, winters became colder and harsher, and summers became hotter and drier. Blowing dust, laden with pesticides and other chemicals, is routinely scoured from the dry lake bed and poses a severe public health hazard.

But more recently, local news reports recorded more rain in the former port city of Aralsk, once stranded 100 kilometers (60 miles) from the shore of the shrunken sea. The sea is now creeping closer to Aralsk, bringing hope to its people.

The Aral Sea recovery project now enters its second phase focused on the revitalization of the dry former seabed with the cultivation of the native shrub saxaul. The plan is to accelerate the expansion of vegetative cover by planting saxaul in dried out areas, which is expected to increase the rate of natural regeneration, attracting other plant and animal species.

Saxaul is a shrub indigenous to the arid salt deserts of Central Asia. Reaching heights of three to 10 meters, its thick bark acts as a water storage organ, so that water for humans and livestock can be extracted by pressing quantities of the bark. This hardy plant is known to prevent sand dune movement and protect arable lands, roads and buildings from sand debris.