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What causes flooding?

Flooding frequently refers to when flood waters inundate the floodplain of a river as the result of a storm or dam break. Flooding occurs when the carrying or holding capacity of a system (comprised of storm sewer inlets, curb and gutter streets, storm sewers, roadside ditches, culverts, creeks, bayous, rivers, lakes, etc.) used to convey runoff, storm water, or other surface water is exceeded, resulting in the inundation of the area adjacent to that system. Flooding may also occur when the costal water level rises significantly above the mean high tide elevation as the result of a surge generated by a storm in the Gulf of Mexico. In summary, flooding is caused by the inadequate capacity of a defined system to convey or hold the excess runoff generated by a storm of a given duration and intensity.
2)What are the advantages and disadvantages of flooding in River nile


Without the Nile, the Egyptian economy would cease to exist.
The Nile irrigates and waters Egypt
The Nile provides transport in Egypt.
The Nile floods annually providing alluvium to the land. This is a good fertilizer to farmlands and is often referred to as "The Gift of the Nile".

The Aswan on High Dam, across the Nile, has helped prevent the annual flooding. This has caused declining agricultural production and the diminishing in size of the Nile Delta.

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