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ORIGINAL RESEARCH article

Front. Earth Sci.

Sec. Geohazards and Georisks

This article is part of the Research TopicMonitoring, Early Warning and Mitigation of Natural and Engineered Slopes – Volume VView all 13 articles

Rainfall-Induced Instability of Mountainous Photovoltaic Slopes under Spatially Non-Uniform Infiltration

Provisionally accepted
daocheng  wangdaocheng wang1liuyi  tangliuyi tang1qiang  liuqiang liu1xin  yexin ye2huan  hehuan he1di  tangdi tang1jingxiang  yangjingxiang yang3Jiachen  ZhaoJiachen Zhao4*
  • 1PetroChina Southwest Oil and Gasfield Company, chengdu, China
  • 2PetroChina Southwest Oil and Gas Field Company Exploration and Development Research Institute, Chengdu, China
  • 3Sichuan Huasheng Energy Development Group Co. , Ltd., chengdu, China
  • 4Sichuan University, Chengdu, China

The final, formatted version of the article will be published soon.

Rainfall-induced slope failures are among the most frequent and destructive geohazards in mountainous regions. In photovoltaic (PV) installations, panel shading and runoff concentration cause highly non-uniform rainfall infiltration, which alters pore-pressure distribution and threatens slope stability. This study develops a coupled hydro-mechanical modeling framework to investigate slope instability under spatially heterogeneous rainfall. By integrating the Richards equation, the Van Genuchten model, and the strength reduction method within a customized FLAC3D platform, the transient evolution of pore-water pressure, matric suction, and shear strength was simulated for both uniform and non-uniform rainfall conditions. The results show that PV panel shading results in pronounced hydrological inhomogeneity, creating asynchronous suction dissipation and inhomogeneous pore pressure build-up across the slope. Non-uniform infiltration accelerates localized saturation beneath exposed infiltration zones while delaying wetting under shaded areas, resulting in lateral hydraulic gradients and early pore-pressure concentration near the slope toe. The coupling between non-uniform infiltration and interlayer hydraulic contrast is the dominant process of slope failure induced by the PV system. The simulation study illustrates the results caused by such neglect of rainfall heterogeneity can lead to overly conservative estimation of slope stability and inadequate predictions of the localized risk. For mountain photovoltaic construction, the proposed framework can serve as a reliable risk-assessment tool and early-warning design tool in nature equipped with spatially variable rainfall.

Keywords: Rainfall-induced landslides, non-uniform infiltration, Hydro-mechanical coupling, unsaturated-saturated soils seepage, slope stability

Received: 07 Nov 2025; Accepted: 29 Nov 2025.

Copyright: © 2025 wang, tang, liu, ye, he, tang, yang and Zhao. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Jiachen Zhao

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