TITLE:
Relationship between Nitrogen Atmospheric Deposition, Discharge and Concentration, and Monthly Change of Those in a River
AUTHORS:
Toshisuke Maruyama, Masashi Yoshida, Keiji Takase, Hiroshi Takimoto, Shigeo Ishikawa
KEYWORDS:
Nitrogen Balance; Wet and Dry Deposition; Altitude Dependence of Atmospheric Deposition and Precipitation; Nitrogen in Snowpack
JOURNAL NAME:
Journal of Water Resource and Protection,
Vol.5 No.3,
March
25,
2013
ABSTRACT: The hypothesis that the product of discharge and concentration of nitrogen (N) in river water is equal to the atmospheric deposition was verified in the mountainous basin of the Tedori River in Japan. To verify this relationship, long-term dataare required to eliminate the effect of short-term variation of the N components. The basin has very high mountains, including Mount Hakusan (2702 maltitude), which is covered with deep snow in winter. Therefore, limited data were used for the estimation of the deposition of the entire basin by assuming a linear relationship of altitude. As a result, it was found that the estimated N concentration coincided well with observed concentrations at six sites—the Shiramine and Kuwajima (upper stream), Nakajima (lower stream) and Dainichi dam, Tedori dam and Senami sites (middle stream). The seasonal variation of N concentrations was low in the snowmelt period and high in autumn through to winter. This was not due to the larger discharge in snowmelt season as it was also found that N deposition was high in winter and low in spring, which indicated a clear relationship between N concentration and monthly atmospheric deposition including N storage in snow pack.