IMD says N-E monsoon reducing despite floods ravaging across states
NEW DELHI: Over a 100 people have died and lakhs of families have been displaced by the ongoing extremely heavy rains and floods in Assam. Last week, several parts of Meghalaya were cut off when incessant rains caused landslides, mudslides and flooding.
Nearly every year these parts of northeast India suffer deluge during monsoon months but India Meteorological Department’s analysis of ‘rainfall variability and changes over different states’ suggests monsoon rainfall over Assam, Meghalaya among other northeastern states is reducing.
Kerala, another state extremely vulnerable to floods and monsoon disasters is also seeing a decreasing trend in rainfall during the main monsoon months of June and July. This pattern indicates that localised, episodic extreme rainfall events are increasing over these regions which trigger disasters but monsoon patterns as such have undergone a significant change in recent decades.
IMD’s state wise data on rainfall variability for the period between 1989 to 2018 for Assam for example states that monthly rainfall for all monsoon months between June to September is recording a decreasing trend.
“During the past 15 to 20 years there has been a very clear and significant decreasing trend in rainfall over northeast India. This is a shift in weather patterns that we are seeing. Monsoonal weather systems have reduced leading to reduced overall rainfall. Depressions used to form during monsoon months that would bring continuous downpour to this region or usually a trough would form in Bihar and move towards northeast India. We are not seeing these formations anymore.
“Short duration heavy rainfall events are expected due to climate change. Northeast India used to receive large amounts or rains and comparatively it still does because the normal here are very high but we are seeing that the quantum of rainfall is increasing along the west coast now,” explained Pulak Guhathakurta, head of the climate division in IMD Pune.