应用稳态模型计算中国南方地表水的硫沉降临界负荷

Calculating of Critical Loads of Sulfur Deposition for Surface Waters in Southern China Using a Steady-state Acidification Model

为了解我国地表水体对酸沉降的响应情况 ,应用基于酸度平衡的稳态模型计算我国南方地表水的硫沉降临界负荷 .文中根据我国实际情况获得了计算地表水背景硫酸盐浓度的经验公式 .结果表明 ,我国南方绝大部分地表水的硫沉降临界负荷大于 2 0keq·(hm2 ·a) - 1,对酸沉降不敏感 .临界负荷小于 2 0keq·(hm2 ·a) - 1的水体主要为部分山地水体 .除了这部分山地水体外 ,其余水体的现状S沉降都没有超过临界负荷 ,表明它们在短期内不会发生酸化 .超临界负荷的地区分布和临界负荷类似 ,均表现为东南沿海的福建、广东和江西 3省低于西南和华中地区 .对模型结果的不确定性分析表明 ,只要模型参数的取值在合适的范围内 ,参数的不确定性对结果造成的误差较小 。

In order to study the response of Chinese surface waters to acid deposition, a steady state model based on acidity balance was applied in this paper to calculate critical loads of sulphur deposition for surface waters in southern China. An empirical equation for Chinese surface waters was obtained to calculate the background sulfate concentration. The results showed that the critical loads of sulphur deposition for most surface waters in southern China were more than 2.0 keq·(hm 2·a) -1 , indicating that they were not sensitive to acidification. Surface waters with critical loads less than 2 0 keq·(hm 2·a) -1 were those waters located on mountains. Except these mountain waters, the critical loads of sulphur depositionf for other surface waters were not exceeded by the present sulphur deposition, indicating acidification will not occur in the near future for these waters. The spatial distribution of critical load exceedance was similar with that of the critical loads, showing the trend of increasing from the southeastern provinces, such as Fujian, Guangdong and Jiangxi, to the southwestern and the central region. The uncertainty analysis of the model results indicated that, the errors of the results caused by the uncertainty of parameters and the input data were minor and acceptable so long as the input data were among the appropriate ranges.