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| DOI：10.13522/j.cnki.ggps.20190051 |
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| Calculation Method Research on Pipe Drain Spacing of Ningxia Yellow River Irrigation Region Based on VBA |
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MAI Wenhui, WANG Hongyu, MA Lijun, LI Xing
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College of Civil and Hydraulic Engineering, Ningxia University, Yinchuan 750021, China
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| Abstract: |
| Subsurface pipe drain project is a vital technique to control the groundwater table for prevent the saline-alkali of cultivated land in the irrigation area.【Objective】For the calculation of the pipe drain spacing, the appropriate calculation method should be selected by considering the drainage conditions and drainage purposes comprehensively. 【Method】Several commonly theoretically calculation approaches were analyzed and their applicative conditions were summarized in this paper. Then the program based on VBA was compiled for optiming calculation methods and calculating the pipe drain spacing. And two typical cases of subsurface pipe drain project were analyed from Ningxia Yellow River Irrigation Region. 【Result】If kH/q[≤]100, the Aviryanov-qu Xingye formula was more suitable; if kH/q > 100, the Hooghoudt formula should be selected in the steady flow state. The pipe drain spacing for the aim to control groundwater table may be determined with groundwater drawdown speed; the pipe drain spacing for the aim to prevent and treatment the saline-alkali soil may be determined with the ratio of drainage water quantity and evaporation capacity in the unstable flow state. 【Conclusion】The program compiled with VBA can solve the problems such as cumbersome iterative and cumulative, which was a convenient operation and has remarkable practicability. The method of unsteady flow state is more available for Ningxia Yellow River Irrigation Region. The pipe drain spacing would be calculated according to the ratio of drainage water quantity and evaporation capacity in Yinbei irrigation area; and it would be calculated according to the speed of groundwater drawdown speed Yinnan irrigation area. |
| Key words: pipe drain spacing; steady flow; unstable flow; VBA program； Yellow River irrigation region |
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