Floods and flooding.

Floods along rivers occur when large amounts of precipitation, often combined with melting snow, cause the discharge of a river to increase far beyond its base flow. The floods may be even higher in cities because of rapid runoff of water from cement into storm sewers. Global warming may increase the intensity and variability of precipitation in many regions, causing more intense flooding. Floods along maritime coastlines can result from storm surges. Higher sea levels due to glacial melting during global warming and more frequent and intense hurricanes may result in more coastal flooding.