Causes of floods
The causes of floods can be natural and unnatural. It is natural when it is due to forces of nature. It is unnatural when it is due due to human activities. When there is excessive rainfall, the water level in riverbanks and in coastal areas increases, which lead to overflow of water into the nearby dry lands. Moreover, earthquakes can cause tsunamis in oceans, which then lead to flooding of lands near the beaches. In heavily populated cities, due to congested buildings and roadways, flooding happens as there is not enough room for water to drain. In such cases, clogged drainage systems lead to even more flooding in the area. In addition, global warming has resulted to the melting of glaciers, which causes rise of sea water levels. This also leads to flooding in the coastal areas. Deforestation also plays a major role in floods.