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Title
  • en Evaluating stream water quality through land use analysis in two grassland catchments: impact of wetlands on stream nitrogen concentration.
Creator
    • en Hayakawa, A.
    • en Shimizu, M.
    • en Woli, K. P.
    • en Kuramochi, K.
Accessrights open access
Rights
  • en From Journal of Environmental Quality, with permission, J. Environ. Qual. Vol. 35, pp. 617-627, 2007
Subject
  • NDC 613.5
Description
  • Abstract en We evaluated the impacts of natural wetlands and various land uses on stream nitrogen concentration in two grassland-dominated catchments in eastern Hokkaido, Japan. Analyzing land use types in drainage basins, measuring denitrification potential of its soil, and water sampling in all seasons of 2003 were performed. Results showed a highly significant positive correlation between the concentration of stream NO3–N and the proportion of upland area in drainage basins in both catchments. The regression slope, which we assumed to reflect the impact on water quality, was 24% lower for the Akkeshi catchment (0.012 ± 0.001) than for the Shibetsu catchment (0.016 ± 0.001). In the Akkeshi catchment, there was a significant negative correlation between the proportion of wetlands in the drainage basins and stream NO3–N concentration. Stream dissolved organic nitrogen (DON) and carbon (DOC) concentrations were significantly higher in the Akkeshi catchment. Upland and urban land uses were strongly linked to increases in in-stream N concentrations in both catchments, whereas wetlands and forests tended to mitigate water quality degradation. The denitrification potential of the soils was highest in wetlands, medium in riparian forests, and lowest in grasslands; and was significant in wetlands and riparian forests in the Akkeshi catchment. The solubility of soil organic carbon (SOC) and soil moisture tended to determine the denitrification potential. These results indicate that the water environment within the catchments, which influences denitrification potential and soil organic matter content, could have caused the difference in stream water quality between the two catchments.
Publisher en The American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America
Date
    Issued2006
Language
  • eng
Resource Type journal article
Version Type VoR
Identifier HDL http://hdl.handle.net/2115/27980
Relation
  • URI http://jeq.scijournals.org
  • isIdenticalTo DOI https://doi.org/10.2134/jeq2005.0343
  • PMID 16510707
Journal
    • PISSN 0047-2425
    • EISSN 1537-2537
      • en Journal of Environmental Quality
      • Volume Number35 Issue Number2 Page Start617 Page End627
File
    • fulltext JEQ35-2.pdf
    • 604.64 KB (application/pdf)
      • Issued2006
Oaidate 2023-07-26