efficiency variations during the first years after construction
Kynkäänniemi, Pia
(2014).
Small wetlands designed for phosphorus retention in Swedish agricultural areas.
Diss. (sammanfattning/summary)
Uppsala :
Sveriges lantbruksuniv.,
Acta Universitatis Agriculturae Sueciae, 1652-6880
; 2014:70
ISBN 978-91-576-8088-4
eISBN 978-91-576-8089-1
[Doctoral thesis]
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PDF
6MB |
Abstract
This thesis examined retention of particles and phosphorus (P) losses from agricultural clay soils in small wetlands with an initial deep area followed by a shallow area with emergent plants. Two long, narrow wetlands (Bergaholm and Nybble) specially designed for P retention (P-wetlands) were constructed, and their efficiency in sediment accumulation were compared with those of six existing wetlands with a different design.
Monthly area-specific P retention was positively correlated with P load in the Ber P-wetland, though outflow P concentrations were occasionally higher than inflow concentrations during extreme flow events or low flow periods with ice cover. However, seasonal sediment deposition was not correlated with hydraulic load (HL), particle load or concentrations, as deposition was mostly higher than particle load in spring-summer. Annual P accumulation was positively correlated with HL (up to a possible maximum) and negatively with an index for fast flow variations (FFI).
Similar annual P retention (mean 89 kg P ha⁻¹ yr⁻¹) in Bergaholm P-wetland was estimated with two independent methods. In contrast, inflow-outflow studies indicated P and particle release in the Nybble P-wetland, while results from sediment plates indicated major sediment accumulation. Measurements of water quality at a point after the deep section indicated that the discrepancy may be attributed to erosion and resuspension in that section. However, further studies are needed to confirm this, and to determine whether it was a temporary phenomenon that will disappear as the wetland bottom stabilises.
In three wetlands with different depth sections, sediment accumulation was higher in deep than in shallow areas. Annual sediment and P accumulation was generally higher in the two P-wetlands than in the other six studied wetlands, and was positively correlated with wetland length to width ratio. Overall, the results suggest that P-wetlands can efficiently retain P lost from agricultural clay soils, provided that HL is not too high or peak-based.
Authors/Creators: | Kynkäänniemi, Pia | ||||||||||
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Title: | Small wetlands designed for phosphorus retention in Swedish agricultural areas | ||||||||||
Subtitle: | efficiency variations during the first years after construction | ||||||||||
Alternative abstract: |
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Series Name/Journal: | Acta Universitatis Agriculturae Sueciae | ||||||||||
Year of publishing : | 1 September 2014 | ||||||||||
Number: | 2014:70 | ||||||||||
Number of Pages: | 62 | ||||||||||
Papers/manuscripts: |
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Place of Publication: | Uppsala | ||||||||||
Publisher: | Dept. of Soil and Environment, Swedish University of Agricultural Sciences | ||||||||||
ISBN for printed version: | 978-91-576-8088-4 | ||||||||||
ISBN for electronic version: | 978-91-576-8089-1 | ||||||||||
ISSN: | 1652-6880 | ||||||||||
Language: | English | ||||||||||
Publication Type: | Doctoral thesis | ||||||||||
Full Text Status: | Public | ||||||||||
Agris subject categories.: | P Natural resources > P10 Water resources and management P Natural resources > P11 Drainage P Natural resources > P30 Soil science and management | ||||||||||
Subjects: | (A) Swedish standard research categories 2011 > 1 Natural sciences > 105 Earth and Related Environmental Sciences > Oceanography, Hydrology, Water Resources (A) Swedish standard research categories 2011 > 4 Agricultural Sciences > 401 Agricultural, Forestry and Fisheries > Soil Science | ||||||||||
Agrovoc terms: | wetlands, design, phosphorus, leaching, farmland, clay soils, filters, sedimentation, water quality, sweden | ||||||||||
Keywords: | Constructed wetlands, phosphorus, clay soils, agricultural land, flow-proportional sampling, retention, sediment accumulation, temporal variations | ||||||||||
URN:NBN: | urn:nbn:se:slu:epsilon-e-2080 | ||||||||||
Permanent URL: | http://urn.kb.se/resolve?urn=urn:nbn:se:slu:epsilon-e-2080 | ||||||||||
ID Code: | 11471 | ||||||||||
Faculty: | NJ - Fakulteten för naturresurser och jordbruksvetenskap | ||||||||||
Department: | (NL, NJ) > Dept. of Soil and Environment (S) > Dept. of Soil and Environment | ||||||||||
External funders: | Stiftelsen Lantbruksforskning | ||||||||||
Deposited By: | Pia Kynkäänniemi | ||||||||||
Deposited On: | 02 Sep 2014 13:00 | ||||||||||
Metadata Last Modified: | 02 Dec 2014 11:08 |
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