A study of non-point source model on wasabi farmland
| Autor: | Yi-Chen Lee, 李怡真 |
|---|---|
| Rok vydání: | 2003 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 91 This study aims at the simulation of non-point source(NPS) loading for a wasabi farmland. The model combines Distributed Rainfall-Runoff Model, soil erosion model, and nutrient model to simulate temporal variability of contamination loading during rainfall events. Furthermore, the calibration and verification process have been test in this study. On the other hand, the regression method is used based on the observed data and to compare with the results of the NPS model. The geometric mean concentration of surface runoff from 6 rainfall events is presented as follows: SS＝511 mg/L, PO43－-P＝2.56 mg/L, TP＝4.7 mg/L, NO3－-N＝1 mg/L, NH4+-N＝0.13 mg/L, Org-N＝0.45 mg/L, TN＝1.94 mg/L. The export coefficients of surface runoff estimated by using the NPS model and the regression method. The results indicate that the two methods are similar. The export coefficients of surface runoff estimated by using the two methods indicated as(unit: kg/ha-year): SS＝597, PO4－-P＝4.49, TP＝6.70, NO3－-N＝1.11, NH4+-N＝0.92, Org-N＝1.39, TN＝3.30. The infiltration term caused by leaching and accumulating in the soil is also evaluated by nutrient budget for the root zoon and one-dimensional advection-dispersion reaction equation (ADR). The amounts of N- and P-leaching and accumulation are 667 kg N/ha-yr and 243 kg P/ha-yr, respectively. This study perhaps first confirmed that the leaching form is important for the non-point source pollution except for surface runoff. This study also establishes a framework of water quality models including surface runoff and infiltration terms to be a consultation for non-point source pollution within a watershed. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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