| Adaptability study on empirical formulae of frequent phreatic evaporation in Xinjiang |
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| DOI：10.7606/j.issn.1000-7601.2008.03.37 |
| Key Words: hreatic evaporation empirical formula phreatic evaporation limit depth phreatic evaporation limit intensity Xinjiang |
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| Abstract: |
| In the arid zone such as Xinjiang the evaporation is intense．The phreatic evaporation affects not only the loss of soil moisture but also the problem of saline-alkali soil and the accurate calculation of phreatic evaporation intensity has significance to the calculation of drainage and prevention of saline-alkali soil．The empirical formulae of phreatic evaporation are frequently used in calculation including Tsinghua equation Averiyanov equation Ye equation and power function．The four formulae have been analyzed basing on the observed data of phreatic evaporation in Changji and Weiganhe of Xinjiang．Simpler determination methods of the limit evaporation depth Hmax in Averiyanov empirical formula and the maximum evaporation intensity Emax and η in the Tsinghua formula are proposed and the accuracy of the calculated evaporation intensity are discussed．The results are as follows：The Tsinghua formula has a widespread versatility in Xinjiang；when the groundwater depth is shallow Averiyanov equation Ye equation and power function have a relative high precision but the precision is low when the depth is deep．The difference between the value calculated using power function formula and the actual value is the biggest．The Averiyanov equation Ye equation and power function fit well in loam than coarse soil． |