酸沉降背景下鼎湖山林区径流的水化学组成特征  

Hydrochemical compositions characteristics of runoff in Dinghushan forest region under the background of acid deposition

作　　者：廖佩琳 高全洲 杨茜茜[1] 李琦 孙渝雯 LIAO Peilin;GAO Quanzhou;YANG Qianqian;LI Qi;SUN Yuwen(School of Geography and Planning,Sun Yat-sen University/Guangdong Key Laboratory for Urbanization and Geo-simulation,Guangzhou 510275,China;Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai),Zhuhai 519080,China;Guangdong Provincial Key Laboratory of Mineral Resource&Geological Processes,Guangzhou 510275,China)

机构地区：[1]中山大学地理科学与规划学院/广东省城市化与地理环境空间模拟重点实验室,广州510275 [2]南方海洋科学与工程广东省实验室(珠海),珠海519080 [3]广东省地质过程与矿产资源探查重点实验室,广州510275

出　　处：《生态学报》2022年第6期2368-2381,共14页Acta Ecologica Sinica

基　　金：国家自然科学基金项目(41871014)。

摘　　要：为了解酸沉降背景下湿热流域源区不同径流的水化学组成特征,选取鼎湖山林区溪流水、土壤水、地下水作为研究对象,在2019—2020年以季节为周期对水化学组成进行了观测分析。结果表明:鼎湖山林区溪流水、土壤水和地下水pH值和酸中和容量较低,分别介于3.45—6.77和-545.51—302.09μmol H^(+)/L之间,水体均呈弱酸性。林区土壤、植被和扬尘颗粒缓冲酸沉降物质的能力较低,对减缓水体酸化的作用较小。不同径流水体化学组成含量存在差异。土壤水K^(+)、Ca^(2+)、NO_(3)^(-)和SO_(4)^(2-)浓度显著高于地下水和溪流水,地下水和溪流水之间除NO_(3)^(-)浓度存在显著性差异外,其余3个指标浓度没有显著性差异;地下水Na^(+)、Mg^(2+)、Cl^(-)、DSi浓度显著高于土壤水和溪流水,土壤水和溪流水之间除Cl^(-)浓度没有显著性差异外,其余3个指标浓度存在显著性差异;这与土壤硝化、吸附、矿物化学风化等作用有关。溪流水水化学组成类型为NO_(3)^(-)·SO_(4)^(2-)⁃Ca^(2+)·Mg^(2+)型,土壤水和地下水水化学组成类型为NO_(3)^(-)⁃Ca^(2+)·Mg^(2+)型。溪流水阳离子主要来源于硅酸盐矿物化学风化和大气沉降,二者的贡献分别为85.76%和14.24%。溪流水SO_(4)^(2-)含量与雨水相差不大,NO_(3)^(-)含量远高于雨水,说明林区森林生态系统淋出了较多的硝态氮。研究成果可以为酸沉降对流域源区径流水化学组成的影响研究提供基础资料,同时为鼎湖山林区的管理提供参考依据。In order to understand hydrochemical compositions characteristics of different runoffs in the source region of humid subtropical basin under the background of acid deposition,hydrochemical compositions of the stream water,soil water and groundwater were analyzed in the Dinghushan forest region on a seasonal basis from 2019 to 2020.The results showed that the pH value and acid neutralization capacity(ANC)of stream water,soil water and groundwater in Dinghushan forest region were low,which were between 3.45—6.77 and-545.51—302.09μmol H^(+)/L,respectively.The stream water,soil water and groundwater were all weakly acidic.Under the influence of long⁃term acid deposition and natural acidification process,soil,vegetation and dust particles in the Dinghushan forest region had low buffering capacity of acid deposition,and had little effect on slowing down water acidification.The concentrations of chemical components in different water bodies were different,which were related to soil nitrification,soil adsorption,mineral chemical weathering,etc.There were little difference in the ratios of cation molar concentrations between stream water and groundwater.The cation of soil water was mainly Ca^(2+),and the molar concentrations of K^(+)+Na^(+) and Mg^(2+) were relatively low.NO_(3)^(-)+SO_(4)^(2-) predominated in the molar concentration ratios of anions and DSi in the three kinds of water bodies,the molar concentration ratios of DSi and Cl^(-) were relatively small.The concentrations of K^(+),Ca^(2+),NO_(3)^(-) and SO_(4)^(2-) in soil water were significantly higher than those in groundwater and stream water.Except for NO_(3)^(-)concentration,there were no significant differences in K^(+),Ca^(2+) and SO_(4)^(2-) concentrations between groundwater and stream water.The concentrations of Na^(+),Mg^(2+),Cl^(-)and DSi in groundwater were significantly higher than those in soil water and stream water.There was no significant difference in Cl^(-) concentration between soil water and stream water,but there were significant di

关 键 词：酸沉降 水化学 化学风化 水体酸化 鼎湖山林区 

分 类 号：P342[天文地球—水文科学]