Evaluating stream water quality through land use analysis in two grassland catchments: impact of wetlands on stream nitrogen concentration.
Evaluating stream water quality through land use analysis in two grassland catchments: impact of wetlands on stream nitrogen concentration.
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DOI：
10.2134/jeq2005.0343
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发表时间：
2006-03
影响因子：
2.4
通讯作者：
Atsushi Hayakawa;Mariko Shimizu;K. Woli;Kanta Kuramochi;R. Hatano
中科院分区：
文献类型：
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作者：
Atsushi Hayakawa;Mariko Shimizu;K. Woli;Kanta Kuramochi;R. Hatano
在日本北海道东部的两个以草地为主的集水区，我们评估了天然湿地和各种土地利用对溪流氮浓度的影响。分析了流域土地利用类型，测定了土壤反硝化潜力，并在2003年的所有季节进行了水质采样。结果表明，溪流NO3-N的浓度和高地面积在流域中的比例在两个集水区之间的高度显着的正相关性。我们假设回归斜率反映了对水质的影响，Akkeshi集水区（0.012 +/- 0.001）比Shibetsu集水区（0.016 +/- 0.001）低24%。在Akkeshi集水区，有一个显着的负相关性之间的比例湿地流域和流NO3-N浓度。流溶解有机氮（DON）和碳（DOC）浓度显着较高的Akkeshi集水区。高地和城市土地利用与两个集水区的流中氮浓度增加密切相关，而湿地和森林往往会减轻水质退化。土壤的反硝化潜力最高的湿地，中河岸森林，最低的草地，并在Akkeshi流域的湿地和河岸森林显着。土壤有机碳（SOC）的溶解度和土壤含水量往往决定反硝化潜力。这些结果表明，流域内的水环境，影响反硝化潜力和土壤有机质含量，可能会导致两个流域之间的溪流水质的差异。
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.