Disrupted Cycles: The Hidden Climate Crisis in Our Rivers

Recent research reveals climate change’s significant impact on river flow seasonality, particularly in the high northern latitudes, with about 21% of surveyed stations showing significant seasonal flow alterations.

A recent study has found that climate change is impacting the timing of river flows, especially in the higher northern regions. River flow patterns, which shift with the seasons, are crucial for managing floods and droughts, ensuring water security, and maintaining the health of global biodiversity and ecosystems.

Although recent studies have shown that climate change has already altered river flow seasonality (RFS), much of the evidence is limited to local regions or fails to consider the impact of climate change explicitly, independent of other human impacts to river flow. Consequently, the impact of climate warming on RFS isn’t fully understood at the global level.

Comprehensive Study on Global River Flow

To address this question, Hong Wang and colleagues combined in situ observations of monthly average river flow from 10,120 gauging stations between 1965 and 2014 with model predictions. They used this data to develop a generalized global seasonality index using apportionment entropy (AE). AE is a statistical method that quantifies how evenly flow raters are distributed across months, which, according to the authors, is well suited to characterize the highly variable flow regimes of rivers globally.

Wang et al. discovered that roughly 21% of long-term river gauging stations have captured significant alterations to seasonal flow worldwide, with low flow periods most affected. Moreover, the findings reveal a discernable weakening in the seasonal cycle of river flow in the northern high latitudes above 50° N that can be directly attributed to climate change.

Reference: “Anthropogenic climate change has influenced global river flow seasonality” by Hong Wang, Junguo Liu, Megan Klaar, Aifang Chen, Lukas Gudmundsson and Joseph Holden, 29 February 2024, Science.
DOI: 10.1126/science.adi9501