FLASH FLOODS IN DHARALI, UTTARAKHAND

Current Context : A cloudburst over the Kheer Ganga River (a tributary of the Alaknanda) triggered flash floods in Dharali, located in the Uttarkashi district of Uttarakhand.

ABOUT CLOUDBURST

• Definition: Rainfall of 10 cm or more within an hour at a location
• Common Location: Hilly regions like Himalayas due to terrain effects
• Prediction Difficulty:
  • Due to small scale and short duration
  • Needs dense radar networks or high-resolution weather models

GEO-CLIMATIC REASONS FOR HIMALAYAN VULNERABILITY

• Orographic Lift: Steep mountain slopes force moist air to rise rapidly, forming tall cumulonimbus clouds
• Heavy Cloud Formation: Clouds become heavy and burst, causing intense rainfall in a short time

ANTHROPOGENIC FACTORS

• Global Warming: Increases frequency of extreme rainfall events
• Study Findings: 2013 Kedarnath floods were amplified by greenhouse gases and aerosols