New Delhi: Brazil’s southern Rio Grande do Sul has witnessed massive floods which have reportedly killed at least 75 people in the last seven days. More than 100 people are missing and over 80,000 people have been displaced as per reports. The floods have wreaked havoc and triggered landslides, washout of roads and collapse of bridges. Electricity and communications supply has been disrupted and over 800,000 people are living without a water supply. In such a scenario, we will learn in this article about the causes of floods and how it affects our lives.

Floods are common natural disasters. It occurs when water overflows and submerges land that is usually dry. Mostly, heavy rainfall, rapid snowmelt, cyclones or other heavy storms or tsunamis in coastal areas cause floods. The most common way of the flood is when rivers or streams overflow their banks which are known as riverine floods. Heavy rain is a primary factor which can overflow a river and spread the water over nearby land. The land surrounding a river is called a floodplain.

Floods can be devastating, leading to heavy and widespread loss of lives and damage to personal property. Between 1998 and 2017, floods affected more than 2 billion people. Those who live near rivers or non-resistant buildings without any warning systems and awareness of flooding hazards are most vulnerable to floods. Floods are mostly of three types: Flash floods are caused by heavy rainfall that quickly increases water level, river floods which occur when rain or snow melt forces a river to exceed capacity and coastal floods are caused by storm surges associated with tropical cyclones and tsunamis.

Sometimes, flood is good as the soil is covered in silt and mud once the water recedes. It makes the land fertile which is beneficial for farmers. However, floods are mostly devastating. It destroys structures like houses, and bridges, uproots trees and destroys cars. Floods lead to soil erosion which destabilises a building. In 2007, severe flooding in Bangladesh damaged over a million homes.

Floods result in widespread loss of lives and massive displacement. Often, the effects are long-term and can be very costly, disruptive and distressing for the communities involved. Floods, while receding, can contaminate water and landscape with hazardous materials. Also, flood water carries disease and can force flood victims to live without clean water for drinking or hygiene for weeks. It can result in deadly diseases like malaria, typhoid, cholera and hepatitis A.