Modification of Green-Ampt model based on multi-stage characteristics of soil water infiltration

Abstract

Water infiltration in unsaturated soil is significantly affected by the multi-stage characteristics that depend on the movement of the wetting front. In this study, the Green-Ampt model was modified in order to accurately capture these multi-stage characteristics during infiltration. The proposed model divides the water-infiltrated unsaturated soil into three zones, while the infiltration process itself is divided into three stages, with the quarter-elliptic wetting front curve being defined. The proposed model, together with other Green-Ampt based models, is analysed and compared with experimental investigations conducted in this study, as well as with other published results from the literature. The modelling results demonstrate that the proposed modified model successfully describes the measured infiltration time for soil columns with different heights. Additionally, a parametric sensitivity analysis of the proposed model reveals that the water infiltration process is mainly controlled by the hydraulic conductivity in the infiltrated zone and the suction head between the wetting front zone and the unpenetrated zone.

Keywords:

• soil water infiltration
• multi-stage characteristic
• parametric sensitivity analysis
• soil water characteristic
• Green-Ampt model

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Competing Interests

The authors have no relevant financial or non-financial interests to disclose.

Author Contributions

All authors contributed to the study conception and design. Material preparation, data collection and analysis were performed by Fusheng Zha, Shengtao Hu and Long Xu. Funding acquisition, data curation and validation were performed by Weimin Ye, Yinbin Shen and Zonghan Chen. The first draft of the manuscript was written by Shengtao Hu and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.

Additional information

Funding

This work was supported by National Key Research and Development Program of China (Grant No. 2020YFC1808101 and Grant No. 2022CSJGG1205), National Natural Science Foundation of China (Grant No. 42030710) and Anhui Provincial Key Research and Development Plan (Project NO. 2022107020014).