硝化を考慮した森林土壌からの硝酸態窒素流出過程の数理モデル化に関する基礎的検討 MATHEMATICAL MODELING OF SOLUTE RUNOFF FROM FORESTED BASIN
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A mathematical model of NO<SUB>3<SUP>-</SUP></SUB>-N runoff process from a forested mountain basin is developed, based on a tank model comprising a surface tank with soilwater storage systems, and a groundwater tank. The model takes account of three elementary processes of NO<SUB>3<SUP>-</SUP></SUB>-N in the forested mountain soil, (a) advection owing to the rainwater movement, (b) solute exchange between mobile and immobile regions, and (c) nitrification by microorganisms in the soil. The nitrification process is modeled using an exponential function of air temperature.<BR>The proposed model is applied to annual observations in 1992 obtained in Shirakawa-tani forested mountain basin (main species Japanese cedar) located on Shikoku island in Japan. The model describes the seasonal change of NO<SUB>3<SUP>-</SUP></SUB>-N streamwater concentration through a year. But, it is found that the model has underestimates objects at the beginning of summer. The deviation may be caused by not using soil temperature, but using air temperature data.
- Doboku Gakkai Ronbunshuu B
Doboku Gakkai Ronbunshuu B 16(1), 57-71, 1998-05
Japan Society of Civil Engineers