What is flooding?

A flood occurred in 1914 in Fredericia.

Flood or flooding is usually a natural overflow of water from its natural bed (bed lower), ie, streams, creeks, lakes, rivers, streams, usually caused by heavy rains and continuous. In the seas and oceans due to storm surge flooding, with or without overtopping of levees, floods are also called, as has occurred in the NetherlandsThe occurrence of flooding is more frequent in the busiest areas where drainage systems are replaced less efficient over time if not properly adjusted or recalculated technically. Often the increase mainly due to the destruction of the population density of certain areas subject to flooding traditionally cyclical.Like any natural phenomenon, one can always calculate the payback period or time to recurrence of a flood making use of statistical methods commonly used in hydrology, as the method of Gumbel or Galton-Gibrat.When this overflow occurs in regions with little or no human occupation, the very nature can take care of absorbing the excess water gradually, causing little damage to the ecosystem, but may cause damages to agriculture.There are errors caused by artificial flooding operations s spillway gates of dams or errors of hydraulic projects such as culverts, bridges, dams, etc..When the overflow occurs in populated areas of small, medium or high population density, the damage may be small, medium, large or very large, according to the volume of water that came out of the bed according to normal and the population density .The science that studies the phenomena of floods is the hydrology that is often taught in courses in Geography, Engineering Hydraulics, Sanitary Engineering, Environmental Engineering and others.Some works can be made for flood control such as culverts, dikes, dams or flood defense works Revitalization Rios, widely used in Holland and Germany.