GUANGZHOU -- Human effects on climate have caused a reduction of river flow seasonality, particularly at high northern latitudes, according to a study published on Friday in the journal Science.

River flow patterns vary with the seasons and this plays a critical role in floods and droughts, water security, and the health of biodiversity and ecosystems worldwide.

Scientists from the Southern University of Science and Technology and the University of Leeds found that approximately 21 percent of long-term river gauging stations exhibited significant alterations in seasonal flow distributions, but two-thirds of these are not correlated to trends in annual mean discharge.

The team of scientists identified a discernible weakening of river flow seasonality above 50 degrees northern latitude, a result of human-induced climate change instead of the natural climate system, according to the study.

The findings, based on observations of monthly average river flow from 10,120 gauging stations between 1965 and 2014, suggested a sustained and considerable diminishment of river flow seasonality if air temperatures continue to rise, said Liu Guojun, the corresponding author of the paper.

The year 2023 has been confirmed as the warmest year since records began, edging closer toward the threshold of 1.5 degrees Celsius above pre-industrial levels set by the Paris Agreement.

"Our study lays the physical science basis that human-induced climate change led to this phenomenon, informing policymakers about the human influence on river flow through climate change," Liu said.