title: Rapid changes of precipitation pH in Qinghai Province, the northeastern Tibetan Plateau.
abstract: Rainfall monitoring programs were conducted in two industrial cities of China's Qinghai Province, Xining and Germu, in some periods of the 1980s and 1990s. The results show that the natural precipitation in this area is originally alkaline. Compared with the late 1980s records, pH values declined significantly from approximately 8 in the 1980s to below 7 in mid-1990s. Such rapid and drastic changes were attributed to fast industrial development that released a large amount of pollutants. Subsequent tough control on pollutant emission partly restored pH values back to above 7 in the late 1990s. The pH and rainfall chemical analyses indicate that alkaline rain in this continental arid region is caused by airborne dusts which originate from local alkaline soils. With decrease of pH value, the total ionic concentration of rainwater is increased because acids were added to the rainwater.
authors.affiliation: Department of Geography, University of Hong Kong, Pokfulam, Hong Kong, PR China.
authors.forename: David D
authors.initials: DD
authors.lastname: Zhang
authors.forename: C Y
authors.initials: CY
authors.lastname: Jim
authors.forename: M R
authors.initials: MR
authors.lastname: Peart
authors.forename: Changxing
authors.initials: C
authors.lastname: Shi
mesh_terms: D015258:Acid Rain; D000397:Air Pollution / Q000032:analysis*; D002681:China; D004391:Dust; D004784:Environmental Monitoring; D006863:Hydrogen-Ion Concentration; D007221:Industry; D012987:Soil
chemical_list: D015258:Acid Rain; D004391:Dust; D012987:Soil