Question

Which of the following is the reason for occurrence of flood?
A) Excessive temperature
B) Heavy rainfall
C) Humidity in air
D) Anticyclones

Answer 1

Hint: A flood is an overflow of water on normally dry ground. loods are a field of study of the discipline of hydrology and are of major concern to agriculture, civil engineering and public health.

Complete answer:
There are various reasons for the flood but first we will understand and go through Heavy Rainfall.
Heavy Rainfall - Flood means overflow of water everywhere. So heavy fall is the simplest reason. When it rains heavily, the infrastructure and system designed to move rainwater to reservoirs gets overwhelmed and water doesn't drain nearly as quickly as it needs to. The drainage system backup and water rises causing floods and going into homes sometimes as well.

Overflowing rivers - Here heavy rainfall must not be the reason for floods. People living in areas near rivers or sea often have a risk of life from overflowing. To prevent overflowing of rivers, dams are built however if and when there is a prolonged rainfall, rivers often overflow to the level of causing flood in the region

Collapsed Dams - If there is a heavy rainfall causing an enormous rise in river level creating pressures on a dam which is higher than its capacity and or when the dam is poorly constructed which is super rare or not managed properly, dams collapse causing a critical situation of flood.

Deforestation - Deforestation is the act of reckless cutting of trees which is also a major cause of flood. You can also call this man-made floods Trees help preventing soil erosion and loss of crops by having a firm firm hold on ground and vegetation which blocks the flow of rain. Removing trees affects the easy flow of water causing the flood.

Thus, option ‘B’ is the correct answer.

Note: There are two kinds of flood, natural and man-made. The causes of both have been mentioned above. Talking about the man-made flood, emission of greenhouse gases, burning of fossil fuels, industrial influences and pollution is causing the depletion of the ozone layer proving to be another cause of man-made floods.