The largest desert reservoir in Asia, Hongyashan, in northwest China's Gansu province, will expand its storage by 49 percent to ease desertification in region, local authorities said Friday.

The storage capacity of the reservoir on the middle reaches of the Shiyanghe River will be increased to 148 million cubic meters to ease desertification in the lower reaches where two deserts merge, according to the provincial water resources department.

The reservoir will transmit 27.2 million cubic meters of water every year to the Qingtuhu Lake to meeting the demands of human activity and the natural environment.

The height of the dams will be increased, starting from this month and 117 hectares of trees will be planted by the reservoir for wind prevention and sand fixation, according to the department. The expansion is imperative because the reservoir, built in 1958, has accumulated 33.18 million cubic meters of sediment, a third of its storage capacity.

The region is one of the major sources of sand storms in northwest China. The reservoir is vital to preventing desertification in the locality.