Chemical composition, seasonal variation and origin of acid precipitation in typical forest areas in Guangzhou
广州市典型森林区酸雨的化学组成、季节变化及其成因探讨

The precipitation has been collected during the period of April 1998 to March 1999 from two typical forest sites in the city of Guangzhou, south China The samples were analyzed for major element compositions (SO 2- 4, NO - 3, Cl -, Ca 2+ , Na +, K +, Mg 2+ , NH + 4). The total annual amout of precipitation is 1625mm during the monitoring period.pH values vary between 3 3 and 6 3,with an average of 4 45.The frequency of acid rain(pH<4 5)is 80%.The amount of acid rain represents abo...