People are increasingly migrating to cities, where flooding is getting worse. At the same time, we need adequate flows in rural areas to sustain the agriculture to supply these burgeoning urban populations." The extensive analysis, published Friday in the Nature Scientific Reports, is based on data from nearly 50,000 rain and river monitoring sites across 160 countries. Whereas extreme "once in a lifetime" floods are causing increasingly large water flows, regular cyclical inundations are having less and less of an effect on the water table, Sharma said. He added that even though the increase in intensity of storms varied around the globe, a persistent finding in the research was that more rain did not translate to more water in river systems. "One thing that came out consistent was the change in rainfall was much more than the change in flow", Sharma added. The paper's authors said engineering solutions were required to adapt to the change in environment. "In places like Arizona, or California, the Netherlands, or the Snowy Mountains Scheme (Australian hydroelectricity system), these things happened because of civil engineers," Sharma said.