Assessing climate change risks to dissolved organic carbon concentrations in drinking water sources using a catchment sensitivity approach

TY - JOUR

T1 - Assessing climate change risks to dissolved organic carbon concentrations in drinking water sources using a catchment sensitivity approach

AU - Vorstius, Carolin

AU - Rowan, John

AU - Brown, Iain

N1 - © 2026 The Author(s).

PY - 2026/1/15

Y1 - 2026/1/15

N2 - Over recent decades, dissolved organic carbon (DOC) concentrations in rivers have increased across the Northern Hemisphere. Climate change contributes to altered thermal, hydrological, and biogeochemical processes. Understanding climatic drivers of DOC production and export is crucial to project future water discolouration and disinfection by-product formation risks. Using raw (untreated) water data from 127 Scottish river and lake catchments, carbon concentrations were related to climate parameters. Based on correlations of total organic carbon (as proxy for DOC), rainfall and temperature data, five “sensitivity” categories were identified. Climate projections using UKCP18 (2041–2060) enabled the identification of those catchments most susceptible to future DOC losses and the prioritisation of anticipatory adaptation actions. Catchments in southeast Scotland were particularly highlighted as at-risk due to summer rainfall reductions. This analysis supports an understanding of climate change risks and informs policy development on land management, water treatment investment, and adaptive management to maintain pre-treatment water quality and ecosystem resilience.

AB - Over recent decades, dissolved organic carbon (DOC) concentrations in rivers have increased across the Northern Hemisphere. Climate change contributes to altered thermal, hydrological, and biogeochemical processes. Understanding climatic drivers of DOC production and export is crucial to project future water discolouration and disinfection by-product formation risks. Using raw (untreated) water data from 127 Scottish river and lake catchments, carbon concentrations were related to climate parameters. Based on correlations of total organic carbon (as proxy for DOC), rainfall and temperature data, five “sensitivity” categories were identified. Climate projections using UKCP18 (2041–2060) enabled the identification of those catchments most susceptible to future DOC losses and the prioritisation of anticipatory adaptation actions. Catchments in southeast Scotland were particularly highlighted as at-risk due to summer rainfall reductions. This analysis supports an understanding of climate change risks and informs policy development on land management, water treatment investment, and adaptive management to maintain pre-treatment water quality and ecosystem resilience.

KW - annual accumulated temperature

KW - classification

KW - drinking water quality

KW - Spearman’s rank correlation

KW - summer effective rainfall

KW - total organic carbon

U2 - 10.1080/02626667.2025.2603420

DO - 10.1080/02626667.2025.2603420

M3 - Article

SN - 0262-6667

SP - 1

EP - 15

JO - Hydrological Sciences Journal

JF - Hydrological Sciences Journal

ER -