Cause of floods in the United States of America By Brian Sia Zi Jie, Joash Chan Wye Kin, Tan Shang Jien, Leonard Khoo Wei Quan and Sharraadh Jeyakuhan.

Cause of floods in the U.S.A. Floods in the United States of America can occur under several types of conditions. Flash flooding occurs when precipitation falls rapidly on saturated soil or dry soil that has poor absorption ability. The runoff collects in gullies and streams and, as they join to form larger volumes, often forms a fast flowing front of water and debris.

Cause of floods in the U.S.A. Floods in the United States of America most often occur in normally dry areas that have recently received precipitation, but may be seen anywhere downstream from the source of the precipitation, even many miles from the source. In areas on or near volcanoes, flash floods have also occurred after eruptions, when glaciers have been melted by the intense heat.

Cause of floods in the U.S.A. Flash floods are known to occur in the highest mountain ranges of the United States and are also common in the arid plains of southwestern United States. Flash flooding can also be caused by extensive rainfall released by hurricanes and other tropical storms, as well as the sudden thawing effect of ice dams.

Cause of floods in the U.S.A. Human activities can also cause floods to occur. When dams, constructed for hydro-electricity, have failed, large quantities of water can be released and can destroy everything within its path.

Cause of floods in the U.S.A. Frozen ground due to cold weather can also cause flood. When the ground is frozen, it cannot absorb any more water when it rains. Full reservoirs can also cause floods. Reservoirs are usually large and they are man-made basins that holds water for irrigation and drinking. It can cause floods by absorbing and spreading out the flood crests flowing down the river.

Cause of floods in the U.S.A. High river and stream level is also another reason to floods in US. If the water level is high, when heavy rain comes, the river and stream will over flow causing floods. Rivers which are covered by ice can also cause flood in US. As the ice at the surface of the river melts, it cracks and floats downstream. This will cause the river to over flow at the downstream of the river.