Increasing numbers of migratory birds have flocked to the well-known beautiful West Lake in Hangzhou, capital of east China's Zhejiang Province, adding color and vitality to its winter scenery.

A recent survey shows there are some 10,000 migratory birds in the lake area, such as wild ducks, cormorants, gulls, and even rare white swans and mandarin ducks now dotting on the lake, as against merely about 1,000 in the early 1990s.

Local ornithologists attribute the drastic rise in the number of migratory birds to a host of measures taken by the local city government to reinforce environmental protection.

The ornithologists describe these birds are just as sensitive to environment as man and say that the multiplicity of birds itself indicates an ever-improving environment.

According to sources with the Hangzhou Municipal Environmental Protection Bureau, hundreds of millions of yuan have been allocated to improve the lake's environment over the last decade. And a three-km long underground channel has been built to refurbish the lake by diverting clean water from the Qiantang River.

Local residents have shown great enthusiasm for afforestation and have planted trees, grass, and flowers around the lake.

The latest monitoring shows that the average yearly visibility in the water is currently more than 50 cm, almost 20 cm more than in 1979. Experts explain that more than 10 million yuan (1.2 million US dollars) are needed for every cm of improvement.