Effect of Unconfined Aquifer Bed Slope on Groundwater Table due to Precipitation by Numerical Modeling

Document Type : Research paper

Authors

1 Former MSc Geotechnical. Student, Department of Civil Engineering, Faculty of Engineering, Yasouj University, Yasouj, Iran.

2 Assistant Professor, Department of Civil Engineering, Faculty of Engineering, Yasouj University, Yasouj, Iran..

3 Assistant Professor, Department of Civil Engineering, Faculty of Engineering, Yasouj University, Yasouj, Iran.

4 Associate Professor, Department of Civil Engineering, Faculty of Engineering, Yasouj University, Yasouj, Iran.

Abstract

The present study investigates the effect of the slope of the Unconfined aquifer bed on groundwater level changes due to precipitation. For this purpose, a schematic design of the problem along with the relevant parameters was modeled in the case where the flow is in the direction of the bed slope in two cases with and without precipitation using the PMWIN MODFLOW software. After validating the numerical modeling results, a parametric study was conducted to investigate the effect of the bed slope, precipitation intensity, and soil hydraulic conductivity coefficient during precipitation on changes in the water level of the free aquifer. The results showed that the effect of the bed slope on the groundwater level is more obvious in heavier precipitation and that the effect of the slope on changes in the groundwater level profile is reduced by reducing the precipitation intensity. The analysis of the different hydraulic conductivity coefficients in the precipitation state at all slopes showed good agreement with each other, which indicates that the ratio of precipitation intensity to hydraulic conductivity coefficient (R/K) is dimensionless. The results indicate that the water level profile at all slopes follows a cubic equation. In the present study, relations were presented for the coefficients of this equation, which ultimately allow the groundwater level to be determined due to precipitation in a situation where the flow is in the direction of the bed slope.

Keywords

Main Subjects

References

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Hydrogeology
Volume 10, Issue 1
August 2025
Pages 35-49

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