Flow-Path Model to Identify the Sources and Factors Regulating the Nitrate Concentration of a Nitrogen (N)-Saturated Stream
Abstract
The Hyakumakidani watershed, one of the streams on Kureha Hill, Toyama, Japan, exhibited that the output N from the watershed to the stream was much higher than the input N into the watershed because of N saturation. A flow-path model, based on a two-stage tank model, was applied to the Hyakumakidani watershed to identify factors regulating the nitrate concentration of the stream water. The model reproduced the discharge and nitrate concentration fairly well (except during the summer) and suggested the flow-path change within the soil was one of the major factors regulating the nitrate concentration.