Groundwater hydraulics · memory · decision
We interpret aquifer tests, groundwater memory, and subsurface thermal systems for decisions that must withstand uncertainty.
Led by Ying-Fan Lin · analytical well hydraulics · transformation uncertainty
Start with a research question
Each short answer links to the public evidence, interpretation scope, and stated boundary behind it.
Lagging Darcy Law is a generalized Darcy-law formulation for testing whether groundwater flux and hydraulic-gradient response adjust over different macroscopic time scales.
Boundary: Not a universal replacement for Theis, Neuman, delayed-yield, dual-porosity, leakage, or numerical groundwater models.
Evidence and scopeFlux-gradient asynchrony is not a simple signal delay; it asks whether different hydraulic quantities move out of phase in ways that change amplitude, recovery, parameter meaning, or decisions.
Boundary: Not a single delay parameter or a purely cosmetic time shift.
Evidence and scopeYing-Fan Lin studies groundwater response, analytical well hydraulics, Lagging Theory, transformation uncertainty, and subsurface-energy decisions.
Boundary: No unsupported ranking, authority, or institutional-status claims.
Evidence and scopeFeatured films
These films move from field measurements to model-conditioned parameters, resolvable aquifer dynamics, and the research workflows used to examine them.
Different physical mechanisms can leave nearly the same drawdown response. This film asks whether we should first identify how many stable dynamic modes the data support, then examine which mechanisms could have produced them. A multiple-memory response remains a testable direction, not a presumed result.
Three wells cannot map an aquifer. This film follows the pumping-test record from measured drawdown to the possibility that groundwater flux and hydraulic gradient evolve on different effective time scales.
At Maheshwaram, the same drawdown record yielded storativity estimates 4,942 times apart under two analytical models. The disagreement begins in interpretation, not measurement.
The same periodic head signal can imply conflicting hydraulic diffusivities when an instantaneous-equilibrium model is made to explain both attenuation and phase. Lagging Theory introduces distinct relaxation times for flux and head equilibration.
Word made review familiar, Overleaf made equation-heavy collaboration practical, and GitHub preserved version history. This working experiment asks whether the everyday draft could remain directly editable on the web, with LaTeX produced when the manuscript is ready.
My Papers, Re-reviewed · Episode 03
My first master's topic spent years in cold storage. I reopened the 2019 ATES paper to ask what survived, what the injection-period solution never promised, and why recovery refused a convenient superposition.
Read the retrospectivePeople and practice
Conference exchange, student-led presentations, derivation, model comparison, and figure checking are part of how the group develops research questions.
One physical question · four research lines
The programme moves from analytical structure to field interpretation, then carries model disagreement into engineering decisions.
Exact and semi-analytical solutions for pumping, boundaries, islands, streams, faults, and near-well effects.
Public record: A publication record spanning radial pumping solutions, boundary effects, island aquifers, and wellbore conditions.
We test when flux and hydraulic-gradient responses evolve on different time scales, and when that distinction matters for aquifer interpretation.
Public record: Lin and Yeh (2017) introduced a lagging formulation for drawdown in a leaky confined aquifer; later work extends the question to periodic signals and related systems.
A measured drawdown or thermal response is not the parameter itself. We examine how analytical-model choice changes the inferred parameter and the decision built on it.
Public record: The current line is a developing framework and a set of bounded demonstrations, not a claim that one model is universally correct.
Thermal response tests, aquifer heat transport, borehole storage, and shallow geothermal design examined with groundwater context included.
Public record: Recent work includes Wang et al. (2026), Case Studies in Thermal Engineering, DOI 10.1016/j.csite.2026.107695, together with analytical heat-transport studies. Site-specific design remains conditioned on groundwater, lithology, and test data.
Research leadership
The group’s work moves from analytical well hydraulics to non-instantaneous responses and model-conditioned uncertainty. The claims below are deliberately tied to the public research record.
Research trajectory
Papers with visual explanations
Each selected paper pairs a plain-language account with its source-bounded visual explanation.
Hsiang-Wen Wang; Ying-Fan Lin*; Chia-Hao Chang; Bo-Tsen Wang; Hikari Fujii; Yu-Feng Forrest Lin; Kuo-Hsin Yang; Jui-Pin Tsai*
The analysis keeps grout heat storage in a thermal response test and separates early-time grout effects from later-time ground-conductivity information.
Ying-Fan Lin*; Barret L. Kurylyk
Two groundwater processes can respond at different rates. Accounting for both reconciles the observed amplitude attenuation and phase shift of periodic head signals at the two field sites.
Ying-Fan Lin∗, Barret L. Kurylyk∗, Adrian D. Werner, Chih-Yu Liu, Cristina Solórzano-Rivas, Jun-Hong Lin
This analytical solution uses image wells to represent pumping, recharge, and coastline geometry in island aquifers.
Student-involved work is marked in the publication archive. The public index currently includes 1 explicitly linked student publication record.
Collaboration
We work with groundwater, geotechnical, and subsurface-energy teams when interpretation changes what should be built, operated, or monitored.
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