Wide Area Distribution of Nitrogen Concentrations in
Mountain Streams of Hyogo Prefecture, Japan

Muramatsu, K.; Komai, Y.; Umemoto, S.; Inoue, T.

doi:2010.15.2.111

Environmental Engineering Research 2010;15(2): 111-115. DOI: https://doi.org/10.4491/eer.2010.15.2.111

Wide Area Distribution of Nitrogen Concentrations in Mountain Streams of Hyogo Prefecture, Japan

K. Muramatsu¹, Y. Komai¹^†, S. Umemoto², and T. Inoue³

¹Department of Environmental Engineering, Osaka Institute of Technology, 5-16-1 Omiya Asahi, Osaka 535-8585 Japan (E-mail:komai@env.oit.ac.jp)
²International Center for the Environmental Management of Enclosed Coastal Seas, DRI East Bldg.5F 1-5-2 Wakinohamakaigan-dori Chuo-ku Kobe Hyogo, 651-0073 Japan (E-mail:umemoto@emecs.or.jp)
³Department of Architecture and Civil Engineering, Toyohashi University of Technology, 1-1 Hibarigaoka Tenpakucho Toyohashi, 441-8580 Japan (E-mail: inoue:@tutrp. tut.ac.jp)

Corresponding Author: Y. Komai ,Tel: +81-6-6954-4512, Fax: +81-6-6954-4512, Email: komai@env.oit.ac.jp

Received: January 13, 2010; Accepted: March 21, 2010.

ABSTRACT

To study the relationship between the concentrations of nitrogen in mountain streams, and anthropologic and natural factors, the water chemistry of the mountain streams in the entire Hyogo Prefecture, Japan, were investigated. A thousand mountain streams were investigated between 1998 and 2001. The concentrations of nitrate nitrogen ranged from 2.92 to 0.1 mg/L, with an arithmetic mean value of 0.45 mg/L. A number of streams showing more than 1.0 mg/L of nitrate nitrogen accounted for 8% of the mountain streams investigated. These results indicated that the concentrations of nitrate nitrogen in the mountain streams were low in the entire Hyogo Prefecture. In general, the mountain stream water in Hyogo Prefecture appears to not have been affected by wet and dry deposition originating from anthropologic sources in mountain streams and Japan. On the other hand, sites with more than 0.8 mg/L nitrate nitrogen were distributed over the entire Hyogo Prefecture, which were classified into five groups. Each group showed unique geographical, geological and anthropological characteristics. No common characteristic among five groups were discover. These results suggest that the cause of high concentrations of nitrogen in mountain streams is not from a uniform set of conditions.