China has agreed to loan Uzbekistan $41.5 million to purchase dredgers to clean the bank of the Amu-Darya River in northwest Uzbekistan, media sources reported on Thursday.

China’s Exim Bank, also known as the Export-Import Bank of China, agreed to the loan at the Uzbek Ministry of Agriculture and Water Resources, the Kyrgyz news agency Kabar.kg reported Itar-Tass as saying on Thursday.

The funds will be put toward the purchase of 30 dredgers, which will clean the banks of the Amu Darya (آمودریا) and its channels in the Uzbek autonomous region of Karakalpakstan and the Khorezm (خوارزم) region.

The funds will be made available in the latter part of 2011, the news agency reported. The loan will have a maturity of 20 years and a five-year grace period, and will be provided as part of China’s and Uzbekistan’s involvement in the regional ssecurity group Shanghai Cooperation Organization (SCO).

Amu Darya is a river almost in reverse, for long reputed to be sourced by a powerful glacier fed stream high in the Pamir Knot at the eastern end of Afghanistan’s Wakhan Corridor, and ending not at the sea but spreading out into the sands of Turkmenistan’s Kyzyl Kum desert, well short of its historic terminus of the inland Aral Sea.

About 1,385,045 km² of land is drained by the Amu Darya into the Aral Sea endorheic basin. This includes most of Tajikistan, the southwest corner of Kyrgyzstan, the northeast corner of Afghanistan, a long narrow portion of western Turkmenistan and about half of Uzbekistan. Part of the Amu Darya’s drainage divide in Tajikistan forms that country’s border with China (in the east) and Pakistan (to the south). About 61% of the drainage lies within Tajikistan, Uzbekistan and Turkmenistan, while 39% is in Afghanistan. Of the area drained by the Amu Darya, only about 200,000 km² actively contribute water to the river. This is because many of the river’s major tributaries (especially the Zeravshan River) have been diverted, and much of the river’s drainage is dominated by outlying desert and steppe.

The abundant water flowing in the Amu Darya almost entirely comes from glaciers in the Pamir Mountains and Tian Shan, which, standing above the surrounding arid plain, collect atmospheric moisture which otherwise would probably have escaped somewhere else. Without its mountain water sources, the Amu Darya would not contain any water because it rarely rains in the lowlands that characterize most of the river. Throughout most of the steppe, the annual rainfall is about 300 mm.