Floods:

A flood is when there is an excessive amount of water and it covers the normally dry area. The science of hydrology includes studying floods. They are the most frequent and pervasive type of severe weather in nature. Because flooding can cover anything from a few inches of water to many feet, floods can have a wide variety of appearances. They may also start out slowly and then pick up speed. These are instant and momentary influxes of a vast region as an overflowing of rivers or reservoirs.

Causes: In general, floods are caused by rain, high winds, cyclones, tsunamis, melting snow, or dam bursts. Floods can take place steadily or can occur instantly because of heavy rains, breaches of the water storage and control structures, and spillover. The process of blocking something with sand or soil (known as siltification) of the rivers and reservoirs could easily further increase the occurrence and magnitude of floods.

Effects:

• Casualties: Human and livestock death due to drowning, harmful grave injuries, and the spread of deadly diseases (epidemics) like cholera, jaundice, diarrhoea, and various infections are the most found challenges posed in flood-affected regions. In these regions, the availability of harmless drinking water is often difficult as the usual sources such as wells are found to be immersed in floodwater. Because of these reasons often people are left with no choice but to drink unsafe water (contaminated), which turns out to be a major reason for various serious diseases.

• Crop loss: Other than the loss of human and cattle life, floods cause severe devastation to standing agricultural crops. Food grains and crops are spoiled by flooding. Floods also might influence some of the attributes of the soil and might turn the soil barren as in the coastal areas, erosion can cause the soil to degrade, or the agricultural land can become salinised because of flooding by seawater.

• Material loss: Household articles together with eatables, electronic goods, beds, clothes, and furniture get immersed in water and get spoiled. Each and every object mounted on the ground, e.g., food stock, equipment, vehicles, livestock, machinery, salt pan, and fishing boats can be immersed and spoiled.

• Structural damage: People’s lives and properties are at risk when mud huts and buildings built on weak foundations collapse during flooding. Agricultural crops, livestock, roads, rails, dams, monuments, and dams may all be affected. Floods may uproot trees and may give rise to landslides and soil erosion.

• Utility damage: There is a threat to infrastructures such as water supply, sewage, communication lines, power lines, railroads, and transportation networks.

Numerous factors, such as a sharp rise in population, fast urbanisation, an increase in economic and development activity in flood plains, and global warming, might be blamed for this. Floods have also happened in places that weren’t previously thought to be prone to flooding. These Guidelines make an effort to address every aspect of flood management. Some of the rivers harming India originate in nearby nations, giving the issue a further complicated layer. We still need to create an effective response to floods, as evidenced by the ongoing and widespread loss of life and harm to public and private property caused by flooding. To help the many implementing and stakeholder agencies successfully address the crucial areas for minimising flood damage, the NDMA Executive Summary Guidelines have been created.