Climate change and increases in drought and rainstorms pose serious challenges to our water management. An international group of scientists have brought together a large body of research on water quality in rivers worldwide. The study shows that river water quality tends to worsen during extreme weather events. As these events become more often and severe due to climate change, ecosystem health and human access to safe water may be increasingly under threat.
The research led by Dr. Michelle van Vliet of Utrecht University analyzed 965 cases of river water quality changes during extreme weather such as drought, heatwaves, rainstorms, and flooding. The analysis shows that in most cases water quality tends to become worse during droughts and heatwaves (68%), rainstorms and floods (51%), and under long-term changes in climate (56%). During droughts, less water is available to dilute contaminants (稀释污染物), while rainstorms and floods generally result in more contaminants that run off from land to rivers and streams. Improvements or mixed responses in water quality are also reported for some cases, for example when increased transport of pollutants is offset (抵消) by more dilution during flood events.
Water quality changes are strongly driven by changes in water temperature. Land use and other human factors such as wastewater treatment also shape how this plays out. “Understanding the complex interplay between climate, land use, and human drivers, which together influence the sources and transport of pollutants is crucial,” says van Vliet. The research also calls for more data collection and studies of water quality in non-Western countries. “We need better monitoring of water quality in Africa and Asia. Most water quality studies now focus on rivers and streams in North America and Europe.”
The results of the study underline the urgent need for a better understanding of water quality changes during extreme weather events. It sounds an alarm to us. Only then will we be able to develop effective water management strategies that can safeguard our access to clean water and ensure ecosystem health under climate change and increasing weather extremes.
【小题1】What can we learn from paragraph 1?| A．Human beings should be blamed for climate change. |
| B．Worsened water quality is threatening the climate. |
| C．Water quality in rivers worldwide is under risk. |
| D．Water management has been improved recently. |
| A．The threats caused by extreme weather. | B．The factors influencing water safety. |
| C．The findings of van Vliet’s research. | D．The design of van Vliet’s experiment. |
| A．Water quality in non-Western countries is more terrible. |
| B．Human activities have a big influence on water quality. |
| C．Related data collection and studies of Europe is adequate. |
| D．Water quality changes are dominated by water temperature. |
| A．Unclear. | B．Contradictory. | C．Doubtful. | D．Approving. |
