TY - GEN
T1 - Dissolved nitrogen removal in the ponded streams of an alluvial, suburban basin with a developing city, western Japan
AU - Shimizu, Yuta
AU - Onodera, Shin Ich
AU - Saito, Mitsuyo
AU - Hirayama, Yasuyuki
AU - Takahashi, Hidehiro
PY - 2009/12/1
Y1 - 2009/12/1
N2 - This study aims to clarify the nitrate removal in a ponded stream with 12 pools, in western Japan. In the summer season, denitrification coincides with nitrate assimilation by phytoplankton in the pool. In addition, organic matter mineralization in sediment also occurs in summer. DN fluxes estimated on the main stream by the chloride ion balance method suggest nitrate has been removed within the pool. However, the estimated amount of nitrogen removed in each pool was quite different. The estimated amount removed was divided into denitrification and assimilation by the Redfield ratio. Consequently, it is suggested that assimilation by phytoplankton contributes significantly to removing dissolved nitrogen in the summer season, while denitrification contributes in autumn. Furthermore, the relationship between the amount of removed dissolved nitrogen, except for assimilation, and characteristics of pools, indicates that the removable amount of DN is larger in the pools characterized by large area, shallow depth or slow flow velocity.
AB - This study aims to clarify the nitrate removal in a ponded stream with 12 pools, in western Japan. In the summer season, denitrification coincides with nitrate assimilation by phytoplankton in the pool. In addition, organic matter mineralization in sediment also occurs in summer. DN fluxes estimated on the main stream by the chloride ion balance method suggest nitrate has been removed within the pool. However, the estimated amount of nitrogen removed in each pool was quite different. The estimated amount removed was divided into denitrification and assimilation by the Redfield ratio. Consequently, it is suggested that assimilation by phytoplankton contributes significantly to removing dissolved nitrogen in the summer season, while denitrification contributes in autumn. Furthermore, the relationship between the amount of removed dissolved nitrogen, except for assimilation, and characteristics of pools, indicates that the removable amount of DN is larger in the pools characterized by large area, shallow depth or slow flow velocity.
KW - Denitrification
KW - River basin scale
KW - Small reservoir
UR - http://www.scopus.com/inward/record.url?scp=78751671923&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=78751671923&partnerID=8YFLogxK
M3 - Conference contribution
AN - SCOPUS:78751671923
SN - 9781907161018
T3 - IAHS-AISH Publication
SP - 143
EP - 149
BT - Improving Integrated Surface and Groundwater Resources Management in a Vulnerable and Changing World
T2 - Symposium JS.3 at the Joint Convention of the International Association of Hydrological Sciences, IAHS and the International Association of Hydrogeologists, IAH
Y2 - 6 September 2009 through 12 September 2009
ER -