Large man-made reservoirs can increase the intensity of rainfall and may damage flood defenses, according to a study to be published in the journal Hydrology. Scientists studying data from 50 rain gauges in Chile found that rainfall patterns were much higher around bodies of water than in similar areas without them. While there is evidence that bodies of water impact rainfall by increasing the amount of water evaporated, some experts also believe that standing bodies of water create circulating air patterns in the atmosphere above the boundary between the water and the land, which can initiate thunderstorms and showers. One study found that extreme precipitation increased by four percent per year after the construction of dams. "Engineers get fired when there's flooding because they didn't do a good design, but in reality they did good work but someone else installed a water reservoir and the climate changed," said one of the report's authors. "The bigger the water body, the greater the effect." For the full story, see http://www.bbc.co.uk/news/science-environment-20663875.