A new analytical expression for ultimate specific yield and shallow groundwater drainage

Dong hui Cheng, Yu hong Wang, Ji bo Duan, Xunhong Chen, Sheng ke Yang

Research output: Contribution to journalArticlepeer-review

11 Scopus citations


The ultimate specific yield, i.e. the specific yield under steady-state condition, is generally dependent on the water table depth in the shallow groundwater systems. This paper presents a new expression to describe this relationship. The expression is based on the relationship between soil water content-soil depths below ground surface near the saturation zone, i.e. water content profile, which can be fitted by the van Genuchten model. Because this model is highly nonlinear, a Taylor series expansion was used to solve the integral equation for specific yield in our study. The new expression was verified by a drainage experiment, and the results demonstrated that the new expression is reliable for eolian sand when the range of water table fluctuation is less than 30cm. The expression is easily applicable because knowledge of the water content profile near the saturation zone is the only requirement. Compared with the expression obtained from the Brooks-Corey model, the new expression can be used for a variety of aquifer and soil media. The improved accuracy of the specific yield provides a better estimate of discharge rates in shallow groundwater systems with water table fluctuations.

Original languageEnglish (US)
Pages (from-to)1905-1911
Number of pages7
JournalHydrological Processes
Issue number8
StatePublished - Apr 15 2015


  • Capillary fringe
  • Specific yield
  • Van Genuchten model
  • Water content profile
  • Water table fluctuation

ASJC Scopus subject areas

  • Water Science and Technology


Dive into the research topics of 'A new analytical expression for ultimate specific yield and shallow groundwater drainage'. Together they form a unique fingerprint.

Cite this