5.
India faced heavy floods this year in Uttarakhand and Kerala. This is most likely due to:
a. Pollution
b. Land use change
c. El Niño
d. Seismic activity
India faced severe floods in Uttarakhand and Kerala during 2025, primarily triggered by extreme rainfall events like cloudbursts and monsoonal deluges. These disasters caused significant loss of life, infrastructure damage, and displacement. For CSIR NET aspirants, understanding the most likely cause among the options requires evaluating each scientifically.
Option Analysis
Pollution (a): Pollution contributes to air quality degradation post-floods via bioaerosols from stagnant water, but it does not directly trigger flooding. No evidence links pollution as the primary cause for Uttarakhand’s flash floods or Kerala’s heavy rain events in 2025.
Land Use Change (b): Deforestation, urbanization, and encroachment on floodplains reduce soil permeability and increase surface runoff, amplifying flood intensity. In Kerala, built-up areas rose substantially from 2000-2017, boosting runoff by 31%; similar patterns in Uttarakhand’s fragile Himalayas worsen debris flows during heavy rains.
El Niño (c): 2025 monsoon occurred under neutral ENSO conditions, with climate change—not El Niño—driving 108% above-normal rainfall and extreme events across 45% of India. El Niño typically weakens monsoons, causing droughts rather than floods.
Seismic Activity (d): Earthquakes occurred in 2025 (e.g., Delhi-NCR), but floods in Uttarakhand and Kerala stemmed from meteorological factors like cloudbursts and GLOFs, not seismic triggers. No direct link exists.
Correct Answer
The most likely cause is b. Land use change. Human alterations like deforestation and construction exacerbate natural heavy rainfall into devastating floods, a recurring factor in both regions.
CSIR NET Insights
Land use changes alter hydrological cycles, reducing infiltration and raising peak discharge—key for ecology and disaster management questions. Climate-amplified rains interact with these changes, demanding integrated land planning.
