Floods are high stream flows, that overlap natural or artificial banks of a river or a stream and are markedly higher than the usual flow as well as the inundation of low land.
Types of floods:
1. Flash floods: Such floods occur within six hours during heavy rainfall.
2. River floods: Such floods are caused by precipitation over large catchment areas or by the melting of snow or sometimes both.
3. Coastal floods: Sometimes floods are associated with cyclone high tides and tsunamis.
Causes of floods:
• Torrential Rainfall
• Encroachment of rivers bank.
• Excessive rainfall in the catchment.
• Inefficient engineering design in the construction of embankments, dams, and canals.
Effects of floods:
• Destruction of drainage system
• Water pollution
• Soil erosion
• Stagnation of water
• Loss of agricultural land and cattle
• Loss of life and spread of contagious diseases.