Installation Research ProjectProject no. 6629 · VARIO
Historic masonry arches and vaults inside Diocletian’s Palace substructures

HRZZ research · Diocletian’s Palace, Split

Understanding water.Protecting heritage.

How does water enter, move and persist beneath a living historic city? VARIO explores the interacting processes behind flooding and water retention in the substructures of Diocletian’s Palace.

Diocletian’s Palace substructures · Photograph: Vladimir Divić

FundingHRZZ · UIP
Installation Research Projects
Scheduled start15 October 2026
Project launch
Research programme36 months
2026–2029
Case studyDiocletian’s Palace
Substructures · Split, Croatia

01 / The project

A hidden water system. A visible need for understanding.

Extreme rainfall, sea-level variability, groundwater and infrastructure performance can interact. In heritage spaces, the depth of water matters—and so does how long it stays.

Variability-aware Modelling of Retention Dynamics in Heritage Substructures under Extreme Events

VARIO develops a hydraulic modelling approach for lower-level heritage spaces where drainage routes and subsurface connections are only partly documented. It combines system reconstruction, targeted observations and scenario ensembles to examine interacting drivers, thresholds and uncertainty.

The research is grounded in the substructures of Diocletian’s Palace. Modelling will begin in a priority western subdomain, with detail added where new evidence can improve the interpretation of water accumulation and retention.

The wider aim is a transferable approach for comparable enclosed or partly buried heritage spaces in coastal cities—connecting water science with conservation decisions.

Rainfall & runoffCoastal water levelsGroundwater responseDrainage & connectivityInfrastructure malfunction

Four research objectives

O1

Identify the combinations

Which combinations of rainfall, coastal water levels and infrastructure conditions lead to critical water accumulation?

O2

Quantify variability

How do variability, uncertainty and dependence between drivers affect water depth and retention duration?

O3

Locate critical zones

Where do spatial hotspots and threshold conditions intersect with archaeologically active and structurally sensitive areas?

O4

Support decisions

How can modelling inform conservation, excavation planning and risk reduction in the historic city?

02 / Research approach

Observe. Reconstruct. Model. Refine.

Three connected work packages move from evidence to hydraulic analysis and decision support. Observations inform models; model results help target the next observations.

The VARIO research cycle · Project graphical abstract
Download graphical abstract ↓
Year 1 · 2026–2027

Understand the hidden system

Reconstruct water sources, pathways and storage zones from heterogeneous evidence. The conceptual model will explicitly distinguish what is observed, inferred and still unknown.

  • Archival drainage plans, LiDAR and conservation records
  • Targeted ERT and GPR investigations, supported by thermal screening
  • Piezometers with CTD loggers for groundwater monitoring
Planned outputsA spatial and historical repository, monitoring setup and a conceptual hydro-architectural model.

Model detail follows the evidence. SWMM and HEC-RAS workflows will be adapted to the geometry, connectivity and observational constraints of the heritage setting.

Transparent assumptions, data provenance and sensitivity analysis are central to the research. The aim is to identify meaningful patterns without over-interpreting poorly constrained inputs.

03 / Preparatory evidence

An emerging picture beneath the stone.

Existing observations and exploratory tests help define the questions VARIO will investigate. These materials precede the project or support its methodological preparation.

Explore the visual evidence
Surface & infrastructure

Reading drainage across centuries

LiDAR-derived surface drainage screening is compared with the reconstructed Roman drainage network. Spatial correspondence helps frame hypotheses about surface–subsurface connectivity; it does not demonstrate present-day hydraulic function.

Preparatory analysis. Historical drainage: Marasović, Perojević & Margeta, Građevinar 66(3), 2014.

Field observations · March 2026

Tracing moisture beneath the Palace

Exploratory thermal screening is shown alongside documented leakage positions. Local temperature anomalies are consistent with some recorded ingress zones and help prioritise closer investigation.

Leakage documentation: A. Doljanin / ART CORE, January 2026. Thermal screening: March 2026. Preparatory evidence, preceding VARIO.

Geometry · Preliminary survey

From a scan to a model domain

A preliminary SLAM survey of the eastern substructures provides a spatial basis for testing geometry preparation. Survey completeness, connectivity and geometric assumptions still require assessment.

Exploratory work supplied by the project team. Shown as methodological preparation, not a completed VARIO deliverable.

Modelling · Exploratory test

A first look at internal flow

An exploratory flow test uses geometry from the eastern substructures. It illustrates a possible modelling workflow; the displayed water depths are scenario outputs, not observed flooding or a validated forecast.

Preliminary simulation. VARIO’s planned modelling begins in an empirically grounded priority western subdomain.

These visuals are preliminary evidence and methodological tests. They are not completed VARIO outputs. In particular, the eastern flow test is distinct from the western subdomain prioritised in the project plan.

Inside the study site

Photographs give context to the spaces and visible features under investigation. They do not establish hydraulic connections or drainage performance.

Vaulted spaces and floor-level features
Floor grates and masonry openings: features whose connectivity and function require investigation.

04 / Science & place

Research that stays connected to the Palace.

Water science can help make uncertain conditions more understandable for the people who conserve, manage and study this living heritage.

Split’s historic core and coastal landscape
A coastal city above. A partly hidden water system below. Photo: Vladimir Divić.

For heritage conservation

Identify critical ingress and retention zones to support monitoring priorities and context-sensitive protective measures.

For archaeological planning

Clarify how water accumulation and persistence may affect archaeologically active and structurally sensitive spaces.

For coastal flood research

Develop transferable methods for analysing compound processes in enclosed heritage spaces with incomplete system knowledge.

05 / News & notes

The beginning of the research journey.

Project announcements and preparatory research notes. New fieldwork, publications and datasets will be added as the research progresses.

15
October 2026
VARIO logo
Planned · 15 October 2026

VARIO is preparing to begin

A three-year programme connecting hidden water pathways, hydraulic modelling and heritage decisions.

From SLAM recording to a flow test
Preparatory work · Geometry & modelling

From SLAM recording to a flow test

An exploratory test in the eastern substructures helps examine the path from survey data to model geometry.

Following the traces of moisture
Preparatory observations · March 2026

Following the traces of moisture

Thermal observations and conservation records help frame the questions for targeted investigations.

06 / Research team

Different expertise. A shared research question.

The team connects hydraulic modelling, coastal processes and the spatial interpretation of heritage structures.

Principal investigator

Morena Galešić Divić

Assistant Professor · University of Split

Leads the scientific direction, integration across work packages and development of the modelling framework. Supervises scenario analysis and synthesis into scientific and decision-support outputs.

ORCID ↗

Martina Milat

Postdoctoral researcher / Senior Assistant

Hydraulic modelling, scenario implementation, sensitivity analysis and spatial interpretation of model outputs.

Emanuela Tomelić Jurović

PhD student / Assistant · FCEAG

Heritage structures, system reconstruction, geometric assumptions and the conservation context.

Marijana Balić

PhD student / Assistant · Faculty of Science

Marine boundary conditions, sea-level variability and interactions with precipitation-driven processes.

Advisory expertise & site cooperation

Jadranka Šepić

Faculty of Science, University of Split · Extreme sea levels and marine boundary conditions.

Robert Šakić Trogrlić

IIASA, Austria · Systemic risk, cascading effects and interpretation of compound events.

Vesna Bulić Baketić

Museum of the City of Split · Site access, documentation and operational knowledge of the substructures.

Planned doctoral research

Building the next generation of expertise

A doctoral researcher role is planned through an application to HRZZ DOK-2026, subject to funding approval and formal recruitment. The intended research path covers field data, hydraulic model development, scenario ensembles and uncertainty analysis.

07 / Outputs & open science

From research questions to shared knowledge.

Planned outputs will be linked here as they are completed. No project publications or public data releases are available yet.

Planned

Scientific publications

Two planned journal papers will address system reconstruction and ensemble-based analysis of retention, interacting drivers and thresholds.

Planned

Data & model package

Selected derived datasets, documented model configurations and publication-supporting material are planned for repository release.

Planned

Maps & guidance

Spatial indicators of accumulation, persistence and critical pathways will support heritage decisions and a final stakeholder workshop.

Open science with clear access conditions: selected derived outputs are intended for Zenodo, with documentation and persistent identifiers. Third-party restrictions, site sensitivity and ongoing publication needs will be respected; not all raw data will be released openly.

08 / Contact & collaboration

A conversation between water science and heritage.

For scientific exchange, site knowledge or collaboration related to VARIO, contact the principal investigator.

Principal investigator

Morena Galešić Divić

Faculty of Civil Engineering, Architecture and Geodesy, University of Split · Matice hrvatske 15, 21000 Split, Croatia

Host institution ↗