QUE : Explain how deforestation contributes to increasing vulnerability to flash floods in India and give other reasons.

Flash floods are sudden and rapid floods that occur over a short period of time. They are usually caused by an increase in the number of hours of heavy rainfall or other intense water accumulation events. According to the US weather agency, the National Weather Service, flash floods occur when rainfall creates flooding in less than 6 hours.

                Of India’s 329 million-hectare landscape exposed to flooding, over 40 million hectares are highly vulnerable. Recently, flash floods were observed in Himachal Pradesh and Sikkim.

• How deforestation causes flash floods in India’s hilly regions
  

•  Removal of trees and shrubs reduces the natural cover that absorbs rainwater, thus reducing the rate of absorption. E.g. Deforested areas experienced severe flooding during the 2018 Kerala floods.
  
•  Impact on soil structure: Tree roots help hold the soil together, but deforestation increases the risk of erosion.
  
•  Landslides: Slopes are more prone to landslides during heavy rainfall, especially in mountainous regions. For example, the 2013 Uttarakhand floods exacerbated the process of landslides.
  

•  Flash floods: Natural causes
  
• Heavy rainfall: Water from heavy rainfall concentrates and flows rapidly through mountainous, rural and urban areas, causing flash floods.
  
• Severe emergencies: Flash floods can also occur due to cyclones, tropical cyclones, or snowmelt.
  
• Sedimentation: The accumulation of sediment in the river makes the river shallower and reduces its water holding capacity.
  
• Flash flood: Man-made causes
  
  Population pressure: Due to large number of people, more materials are required, such as wood, land, food, etc. Thus, overgrazing, over-cultivation and soil erosion increase, which increases the risk of floods e.g. flooding problem in cities like Chennai and Mumbai

•  Deforestation: Forest areas are used for settlements, roads and agricultural lands, which reduces the number of trees. Forest fires are also a cause of deforestation.
  
•  Dam failure: Water can enter residential areas and agricultural areas due to dam failure.
  
•  Tourism and road expansion: Construction of four-lane and two-lane roads without necessary geological studies due to tourism—operated road expansion is a factor for flash floods.
  

• Unorganized urbanization: Resources are misused for convenience.
  
•  Poor water and sewage management: Old drainage and sewage systems are not repaired and waterlogging occurs during monsoon.

                           Deforestation has significantly increased India’s vulnerability to flash floods. This requires collective action, strengthening flood policy and harmonious coexistence with the environment.