Investigation of estimation of hydraulic parameters in heterogeneous soil

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Akhtar Ali - , The University of Agriculture, Peshawar, Ningxia University (Author)
  • Zhang Wei Jiang - , Ningxia University (Author)
  • Wang Xu Dong - , Ningxia University (Author)
  • Ehtesham Ahmed - , Chair of Urban Water Management (Author)
  • Fazli Hameed - , University of Swabi (Author)
  • Ali Muhammad - , The University of Agriculture, Peshawar (Author)

Abstract

Data availability for in situ spatial variability assessment of hydraulic parameters is always limited in the vadose zone. In this work, laboratory and in situ experimental methods of parameter estimation were compared to investigate the best estimation method for heterogeneous soil. The Marquardt-Levenberg and non-linear least-squares optimisation algorithms were used for parameter estimation. The simulation error was minimised by selecting sensitive parameters during the numerical solution. The shape factor n was found to be the most sensitive parameter, followed by water content θs, saturated hydraulic conductivity (SHC) and the inverse of the air entry α. Compared with the in situ cumulative infiltration and simultaneous methods, the outflow method resulted in the best fit by minimising the error. During the comparison of outflow and cumulative infiltration methods, only θs showed a significant difference (p=0.00). On the other hand, SHC showed a non-significant difference (p=0.439) when the outflow and simultaneous methods were compared. During model predictions, the SHC measured by the simultaneous method showed reasonable estimates for surface horizon and weak correlations (0.79 and 0.77) with deep soil water content, which could be improved by adding more hydraulic parameters. The cumulative infiltration numerical solution resulted in the most reliable estimates of hydraulic parameters for in situ heterogeneous soil.

Details

Original languageEnglish
Pages (from-to)66-81
Number of pages16
JournalProceedings of the Institution of Civil Engineers: Water Management
Volume176
Issue number2
Publication statusPublished - 1 Apr 2023
Peer-reviewedYes

Keywords

Sustainable Development Goals

ASJC Scopus subject areas

Keywords

  • barrages, climate change, dams, drainage, irrigation, reservoirs