| Study on variation of subsurface shape factor of border irrigation based on water balance principle |
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| DOI：10.7606/j.issn.1000-7601.2013.05.042 |
| Key Words: border irrigation water volume balance model dimensi
onal analysis subsurface shape factor |
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| Abstract: |
| In the traditional water movement models of border irrigation based on the principle of water volume balance, it was usually supposed that the subsurface shape factor was a constant value in the same border irrigation, which affected the precision of models. Based on the principle of water volume balance and combined with dimensional analysis, the variation of subsurface shape factor was studied and an empirical formula that could be used to compute the value of subsurface shape factor was proposed. The results showed that the subsurface shape factor was not a constant value in the same border irrigation, but it was variable along with the change of irrigation time, water advance d
istance and other factors. The validity of the proposed method was verified by some existing literatures. The results showed that the precision of water volume balance model could be improved in simulating water movement process of border irrigation when the variation of surface shape factor and subsurface shape factor was considered. The results also showed that the proposed empirical formula was reliable in computing the subsurface shape factor of border irrigation. |