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BRIEF RESEARCH REPORT article

Front. Earth Sci.

Sec. Interdisciplinary Climate Studies

Volume 13 - 2025 | doi: 10.3389/feart.2025.1601966

This article is part of the Research TopicNew Challenges for Baltic Sea Earth System ResearchView all 9 articles

A Conceptual Model Framework for Integrating Monitored-Unmonitored and Surface-Subsurface Flow Contributions to the Baltic Sea

Provisionally accepted
  • 1Royal Institute of Technology, Stockholm, Sweden
  • 2Stockholm University, Stockholm, Sweden

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

Understanding the total water flows and pollutant loads to the Baltic Sea is important for effective coastal-marine ecosystem management. Current assessments often overlook the unmonitored flows and submarine groundwater discharge (SGD). This study proposes and outlines a conceptual modelling framework for overcoming this common neglect by integrated quantification of (1) the monitored surface water flows, and the unmonitored (2) surface water flows and (3) SGD from land to the Baltic Sea. The study outlines how unmonitored runoff and SGD can be estimated by various quantification approaches based on commonly available hydro-climatic, hydrogeological, and other characteristic catchment data. It also describes how modules for the different monitored and unmonitored discharge components are linked and should be integrated in modelling to total annual, seasonal, or finer-resolved water flows to the Baltic Sea, and analogously also in other coastal regions around the world. Though quantitative modelling remains ongoing, the conceptualization opens pathways to improve assessments and management of freshwater flows and associated pollutant loads to the Baltic Sea.

Keywords: Baltic Sea, Conceptual Model, Freshwater inflows, groundwater modelling, regionalization, Submarine groundwater discharge (SGD), Unmonitored catchments, water balance

Received: 28 Mar 2025; Accepted: 18 Aug 2025.

Copyright: © 2025 Vijayan, Kalantari and Destouni. 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: Arya Vijayan, Royal Institute of Technology, Stockholm, Sweden

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