[Mapping critical loads of acid deposition for Chinese surface waters using a steady-state method]

In order to evaluate the response of Chinese surface waters to acid deposition, a steady-state method based on acidity balance was applied to map critical loads of acid deposition for surface waters in China. The results show that the critical loads of sulfur deposition for Chinese surface waters had distinct spatial distributions. Surface waters sited in the north of Daxinganling region have lowest critical loads of sulfur deposition, most of that were lower than 2 keq.(hm2.a)-1. Critical loads of sulfur deposition for those southern surface waters were within the range of 2-10 keq.(hm2.a)-1, while in the other parts of China, most surface waters had critical loads of sulfur deposition higher than 10 keq.(hm2.a)-1. The spatial and values pattern of critical loads of acidity for Chinese surface waters were very similar with that of the critical loads of sulfur deposition. Since critical loads of acidity for most Chinese surface waters were more than 2 keq.(hm2.a)-1, it can be concluded that they were not sensitive to acidification and that acidification will not occur in the near future for most these waters.