A new paper by Professor Jim Best and University of Southampton professor Stephen Darby, published in the journal One Earth, takes a big-picture approach to review the health and resiliency of the world’s large river systems, their deltas and their vulnerability to extreme events.
Rivers respond to changes in the environment through self-adjusting processes of erosion and sedimentation, the researchers said. When not stressed by extreme events like flooding or drought, these responses typically allow rivers to absorb change. However, data from many new studies now suggest that the world’s great waterways are becoming more vulnerable as the effects of human activity and climate change combine and compound.
“Climate change is of huge importance in terms of changing flood or drought frequency and intensity,” Best said. “However, there is a range of other stressors affecting big rivers such as damming, sediment mining, pollution, water diversions, groundwater extraction and the introduction of nonnative species – all of which affect rivers on a timescale that has much more immediate consequences.”