中文摘要：

采用蒸馏水稀释硫酸溶液获得不同浓度硫酸溶液来模拟不同pH值酸雨,并利用硫酸溶液进行多次积水淋溶红壤试验,揭示多次酸雨淋溶过程中红壤物理特征及入渗特性演变规律。试验结果表明：与对照处理组（蒸馏水）相比较,pH=2的硫酸溶液各次入渗速度平均降低了106%,且随着淋溶次数（x）的增加,平均入渗耗时增加百分比（y）也增加,其关系可用对数函数y=70.94ln（x）＋28.53（R2=0.994）描述;pH=3硫酸溶液入渗速度平均降低了20%,随着淋溶次数增加入渗速度衰减;pH=5硫酸溶液各次入渗速度基本保持稳定,且平均入渗速度比对照组快。与初始土壤容重相比较,对照组多次淋溶处理后土壤上层容重减小,下层增大,其他处理各组土壤容重却平均增大了6%,但各处理组的上层土壤容重比下层的小。红壤经不同溶液多次淋溶处理后,其水分入渗速度、扩散度大小关系为：硫酸溶液（pH=5）〉蒸馏水〉硫酸溶液（pH=3）〉硫酸溶液（pH=2）。

英文摘要：

Acid rains with different pH values were simulated by using dilute sulfuric acid solutions.The physical properties and infiltration characteristics of red soil under leaching sulfuric acid solution repeatedly were investigated.The results showed that,compared with the control solution（distilled water）,acid solution with pH value of 2decreased soil infiltration rate by 106% averagely.The percentage increase of infiltration consume time（y）increased with the increase of leaching times（x）,and their relationships could be described by the logarithmic function：y=70.94ln（x）＋28.53（R2=0.994）.Solution with pH of 3decreased soil infiltration rate by 20% averagely,and infiltration rate reduced with the increase of leaching times.However,soil infiltration rate had no change under the leaching of acid solution with pH of 5,and the average infiltration rate was faster than that in control treatment.In control treatment,compared with initial soil bulk density,soil bulk density decreased in upper soil layer and increased in subsoil after repeated leaching tests.In the other treatments,soil bulk density increased by 6%averagely,and was larger in subsoil than in upper layer of soil.The results showed that the infiltration rate and diffusivity of red soil in treatments using different leaching solutions listed in the order of acid solution with pH of 5〉distilled water〉acid solution with pH of 3〉acid solution with pH of 2.