Drought could become a serious problem in Europe by the end of the century, scientists have warned.
Climate change combined with intensive water use is likely to lead to worsening dry spells across many areas, including parts of the UK, predicted the researchers.
Conditions were likely to be most severe in southern Europe, according to a new climate model study.
In the Iberian peninsular, southern France, Italy and the Balkans, minimum river flows were expected to fall by up to 40% and periods of water deficiency to increase by 80% due to climate change alone.
Although the simulation was based on average global temperatures rising by up to 3.4C compared with what they were in 1961, warming in Europe could be much stronger, it was claimed.
"Over the Iberian peninsular, for example, summer mean temperature is projected to increase by up to 5C by the end of this century," said hydrologist Dr Luc Feyen, from the European Commission's Joint Research Centre (JRC), who took part in the study.
Intensive water use will further aggravate drought conditions by 10% to 30% in southern, western and central Europe as well as some parts of the UK, suggested the findings reported in the journal Hydrology and Earth System Sciences.
"Our research shows that many river basins, especially in southern parts of Europe, are likely to become more prone to periods of reduced water supply due to climate change," said study leader Dr Giovanni Forzieri, a climate risk management expert at the JRC.
"An increasing demand for water, following a growing population and intensive use of water for irrigation and industry, will result in even stronger reductions in river flow levels."
The scientists projected different climate change scenarios on to a hydrological model which mimicked the distribution and flow of water on Earth.
The model was run until 2100 for all river basins in Europe to predict how drought conditions might change during the rest of this century.
In the past three decades, drought has already cost Europe more than 100 billion euros (£82.6 million), the scientists pointed out.
"The results of this study emphasise the urgency of sustainable water resource management that is able to adapt to these potential changes in the hydrological system to minimise the negative socio-economic and environmental impacts," said Dr Forzieri.