中国七大区降水化学特性的空间差异及成因

The Spatial Differences of Chemical Characteristics of Precipitation in Seven Regions of China

选取中国七大区的33个省及城市20世纪90年代降水监测资料,通过对比分析,对中国七大区的降水化学特性、空间差异及成因进行了初步研究。结果表明,七大区降水中离子组成基本一致,但是主要离子含量差别较大;降水酸性也表现出明显的差异,总体表现为北方偏碱性,南方偏酸性,并且自东北向华南呈增强趋势;20世纪90年代中国大气硫污染突出,东北、西北地区SO42-及Ca2+含量是其他地区的2倍以上,并且北方降水中NH4+浓度较高,因而针对不同地区的降水化学特性,应采取不同的污染防治措施。

Based on the precipitation data of 33 provinces and cities in China in 1990s, the basic chemical characteristic and spatial differences of precipitation in seven regions were analyzed. The results showed that there were obvious differences in the contents of main ions among the seven regions though the composition of ions was near the same. The acidity of pre- cipitation occurred differently in these seven regions. In detail, the acidity increased from northeast to south China. Sulphur pollution was terrible in 1990s in China with the concentrations of S042- and Ca2~ in northeast and northwest China 2 times higher than in other areas and the NH4＋ concentration in the north was higher than that in the south. Consequently, different preventing and remedying pollution measures should be taken in different regions.