Physics-constrained symbolic regression for discovering closed-form equations of multimodal water retention curves from experimental data

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Kim, Yejin, Suh, Hyoung Suk
Format: Preprint
Published: 2026
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866914367564414976
author Kim, Yejin
Suh, Hyoung Suk
author_facet Kim, Yejin
Suh, Hyoung Suk
contents Modeling the unsaturated behavior of porous materials with multimodal pore size distributions presents significant challenges, as standard hydraulic models often fail to capture their complex, multi-scale characteristics. A common workaround involves superposing unimodal retention functions, each tailored to a specific pore size range; however, this approach requires separate parameter identification for each mode, which limits interpretability and generalizability, especially in data-sparse scenarios. In this work, we introduce a fundamentally different approach: a physics-constrained machine learning framework designed for meta-modeling, enabling the automatic discovery of closed-form mathematical expressions for multimodal water retention curves directly from experimental data. Mathematical expressions are represented as binary trees and evolved via genetic programming, while physical constraints are embedded into the loss function to guide the symbolic regressor toward solutions that are physically consistent and mathematically robust. Our results demonstrate that the proposed framework can discover closed-form equations that effectively represent the water retention characteristics of porous materials with varying pore structures. To support third-party validation, application, and extension, we make the full implementation publicly available in an open-source repository.
format Preprint
id arxiv_https___arxiv_org_abs_2603_03346
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Physics-constrained symbolic regression for discovering closed-form equations of multimodal water retention curves from experimental data
Kim, Yejin
Suh, Hyoung Suk
Geophysics
Artificial Intelligence
Symbolic Computation
Modeling the unsaturated behavior of porous materials with multimodal pore size distributions presents significant challenges, as standard hydraulic models often fail to capture their complex, multi-scale characteristics. A common workaround involves superposing unimodal retention functions, each tailored to a specific pore size range; however, this approach requires separate parameter identification for each mode, which limits interpretability and generalizability, especially in data-sparse scenarios. In this work, we introduce a fundamentally different approach: a physics-constrained machine learning framework designed for meta-modeling, enabling the automatic discovery of closed-form mathematical expressions for multimodal water retention curves directly from experimental data. Mathematical expressions are represented as binary trees and evolved via genetic programming, while physical constraints are embedded into the loss function to guide the symbolic regressor toward solutions that are physically consistent and mathematically robust. Our results demonstrate that the proposed framework can discover closed-form equations that effectively represent the water retention characteristics of porous materials with varying pore structures. To support third-party validation, application, and extension, we make the full implementation publicly available in an open-source repository.
title Physics-constrained symbolic regression for discovering closed-form equations of multimodal water retention curves from experimental data
topic Geophysics
Artificial Intelligence
Symbolic Computation
url https://arxiv.org/abs/2603.03346