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| Titel |
Studies of acid deposition and its effects in two small catchments in Hunan, China |
| VerfasserIn |
N. Xue, H. M. Seip, B. Liao, R. D. Vogt |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1027-5606
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| Digitales Dokument |
URL |
| Erschienen |
In: Hydrology and Earth System Sciences ; 7, no. 3 ; Nr. 7, no. 3, S.399-410 |
| Datensatznummer |
250004639
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| Publikation (Nr.) |
 copernicus.org/hess-7-399-2003.pdf |
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| Zusammenfassung |
| 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 μmolc L-1 and 152 μmolc L-1,
respectively. Wet deposition of sulphate has been estimated as
4.3 gS m-2yr-1 and 3.4 gS m-2yr-1 at BLT and
LKS, respectively. Estimates of the corresponding total depositions (dry + wet) are
6.1 gS m-2yr-1 and 5.3 gS m-2yr-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 Feox and Alox. 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 |
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