Pre-Monsoon Season Floods Responsible for Landslides in India

A week of heatwaves ended when a large group of storm cells dumped extreme rainfall on eastern India from 22 to 25 April. Over 16 people died and hundreds of others displaced by raging flood waters and damaging landslides in the districts of Assam, Nagaland and Arunachal Pradesh. With the beginning of monsoon season predicted to start in June, the already overflowing Brahmaputra, Burhidihing and Desang rivers indicate that this season could be particularly damaging.

The above video, powered by Earth Networks Total Lightning Network, shows the path of the storms with lightning striking the regions of Assam and Arunachal Pradesh from 22 April to 23 April. The storms appear to stall in southern and western Assam as well as Nagaland. This prolonged rainfall contributed to flooding and landslide damage.

3 dtas india and cell tracks

The lightning from this video also indicates the power of the storm cells that caused these floods and landslides. Earth Networks issued three Dangerous Thunderstorm Alerts (purple polygons displayed above) on 23 April as the storm moved eastward across the regions.

Flood Damage

An estimated 42,000 people were affected by the floods in the districts of Assam, Arunachal Pradesh, Lakhimpur, Jorhat, Dima Hasao and Sivsagar according to the State Disaster Management Authority (SDMA). Some communities in Sivasagar were completely cut-off by flood waters after the storms.

Landslide Damage

Photo: NDMA India

The Indian Army recovered 16 bodies from the landslide in Phamla, Tawang district of Arunachal Pradesh on 21 and 22 April. The damage from the landslide is pictured above. Other landslides occurred in Dimo Hasao, Nagaland and Assam. Following these tragic landslides, the India Meteorological Department (IMD) issued warnings for at least nine other states.

Slope saturation by water is the primary cause of landslides. Landslides can be triggered by intense rainfall, like in these cases in India; however, they can also be triggered by snowmelt, changes in ground-water levels and water level changes along coastlines and rivers. Earth Networks will continue to monitor the area as the monsoon season kicks off.