Studies of acid deposition and its effects in two small catchments in Hunan, China
Studies of acid deposition and its effects in two small catchments in Hunan, China
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DOI：
10.5194/hess-7-399-2003
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发表时间：
2003-06
影响因子：
6.3
通讯作者：
N. Xue;H. Seip;B. Liao;R. Vogt
中科院分区：
文献类型：
--
作者：
N. Xue;H. Seip;B. Liao;R. Vogt
抽象的。通过对湖南省两个小流域降水、溪水、土壤水和土壤化学成分的分析，研究了酸沉降及其影响。一处是位于湖南省省会长沙郊区的临科所，另一处是位于湖南南部郴州郊区的白鹿塘。湿沉淀物的体积加权平均pH值和硫酸盐浓度分别为4.58(BLT)和4.9(LKS)和174μmolc L-1和152μmolc L-1。BLT和LKS的硫酸盐湿沉降量分别为4.3gsm-2yr-1和3.4gsm-2yr-1。相应的总沉积量(干+湿)估计为6.1gsm-2年-1和5.3gsm-2yr-1。降水和穿透雨中，阴离子以硫酸盐为主，阳离子以钙为主。在溪水和土壤水中，硝酸盐当量略高于硫酸盐，镁(Mg)不比钙(Ca)低太多。测定了两个集水区5个森林土壤剖面(由4个土层组成)的土壤pH值、土壤有机质(SOM)含量、交换性酸性阳离子、交换性盐基阳离子、有效阳离子交换量(CeCe)、盐基饱和度(BS)和铝(Al)和铁(Fe)库。与LKS土壤相比，BLT土壤一般更酸性，BS更低，Al和Fe库更高。表层土壤(即O层和A层)的Al和Fe库普遍高于深层土壤(即E层和B层)，尤其是在酸性最强的位置(BLT)。除无定形Fe-Ox和Al-Ox外，两个流域的Fe-Ox和相应的Al-Ox之间存在显著的相关性。考虑到硫酸盐的长期大量沉积，未来存在酸化造成生态破坏的风险，特别是在BLT集水区，尽管尚未观察到该集水区的植被破坏。这种情况似乎代表了湖南的大部分地区。关键词：酸沉降、土壤酸化、集水、铝池、铁池
Abstract. Acid deposition and its effects were studied by analysing the chemistry in precipitation, stream water, soil water and soils in two catchments in Hunan. One site, Linkesuo (denoted LKS), is on the outskirts of Changsha, the provincial capital of Hunan, the other (Bailutang, denoted BLT) on the outskirts of Chenzhou in southern Hunan. Volume-weighted average pH values and sulphate concentrations in wet deposition were 4.58 (BLT) and 4.90 (LKS) and 174 μmol c L -1 and 152 μmol c L -1 , respectively. Wet deposition of sulphate has been estimated as 4.3 gS m -2 yr -1 and 3.4 gS m -2 yr -1 at BLT and LKS, respectively. Estimates of the corresponding total depositions (dry + wet) are 6.1 gS m -2 yr -1 and 5.3 gS m -2 yr -1 . In precipitation and throughfall, sulphate was the major anion and calcium the major cation. In stream and soil water, nitrate was slightly higher than sulphate on an equivalent basis and magnesium (Mg) not much lower than calcium (Ca). Important soil properties, such as soil pH, soil organic matter (SOM) content, exchangeable acidic cations, exchangeable base cations, effective cation exchange capacity (CECe), base saturation (BS), and aluminium (Al) and iron (Fe) pools, were determined for five forest soil profiles (consisting of four horizons) in each of the two catchments. The soils in BLT are generally more acid, have lower BS and higher Al and Fe pools than the LKS soils. The Al- and Fe-pools were generally higher in the topsoils (i.e. the O and A horizons) than in deeper soils (i.e. E and B horizons) especially at the most acidic site (BLT). There are significant correlations between Fe-pools and the corresponding Al-pools in both catchments except between the amorphous Fe ox and Al ox . Considering the long-term high deposition of sulphate, there is a risk of future ecological damage due to acidification, especially in the BLT catchment, although vegetation damage has yet to be observed in the catchments. This condition appears to be representative of a large part of Hunan. Keyword: acid deposition, soil acidification, catchment, Al-pools, Fe-pools, Hunan