Acid Rain

State

Acid rain has mainly been distributed in the areas to the south of Yangtze River and to the east of the Qinghai-Tibet Plateau and in Sichuan Basin. In Mid-China, Southwest-China, East-China and South-China acid rain has reached or passed the critical load.

In 1996, the air pollution caused by acid rain was universally serious and the affected areas were expanded, covering 30 per cent of the total territory. According to the monitoring data for 84 cities within the State-controlled-Network, the number of cities with annual average pH value of acid rain lower than 5.6 was 43.The acid rain frequency was higher than 60% in 24 cities.

In 1997, the annual average pH value of precipitation varied from 3.74 to 7.79

There were 44 cities with annual average precipitation pH values lower than 5.6, accounting for 47.6% of the total number of the cities that were monitored. Of the southern cities (those south of the Yangtze River), 75% had average pH values lower than 5.6. Changsha, Zunyi, Hangzhou, and Yibin had the pH value lower than 4.5. Among the cities under monitoring, 71.7% of southern cities saw the occurrence of acid rain. Moreover, in 3 of the cities that were monitored, Changsha, Jingdezhen and Zunyi, the acid rain frequency was higher than 90%. Among the northern cities, Tumen, Qingdao and Taiyuan have seen precipitation with average pH values lower than 5.6.

Central China was the area that suffered most from acid rain, with the average pH value of precipitation lower than 5.0, and the acid rain frequency higher than 70%.

The acid rain pollution in the southwestern areas was also very serious. With the exception of Chongqing, the average pH value of the central districts was lower than 5.0 and the acid rain frequency was 70%

The acid rain in southern China was mainly distributed in the Pearl River delta and central and eastern areas of Guangxi. In 1997, the average pH value of precipitation was higher than that of the precious year, but the acid rain frequency had increased.

In the north, rain in Qingdao and Tumen was of a low pH value and the frequency of acid rain was relatively high. These two areas were the ones in the north to suffer most frequently from acid rain.

SO2 Concentration Distribution by Provinces in China