Sometimes, because of excessive rain, rivers and canals begin overflowing and the adjoining lands start submerging under water. This condition is called a flood; it can cause epidemics and serious threat to life and property.
However, drought is a condition in which rain over an area is insufficient or completely absent for a long period of time. This can cause plants to die, resulting in a famine.
Both these events occur naturally and can cause heavy loss to life and property. The economy of a country also gets affected.