Abstract
A mathematical runoff model of solutes from forested mountain basins is developed, based on a tank model comprising a surface tank with soilwater storage systems, and a groundwater tank. The model takes account of two elementary processes, (a) advection owing to the rainwater movement and (b) solute exchange between soil aggregate and adjacent soilwater. The proposed model is applied to observations of streamwater solute concentration (Cl-and SO42-) obtained from a forested mountain experimental basin (main species Cryptomeria japonica). The basic model structure is verified by the observation of solute concentrations in both streamwater and soilwater.
