Satellite-based monitoring of recent heavy flooding over north-eastern states of India in July 2019

Abstract

South-west monsoon of 2019 advanced towards northern parts of India during the first week of July. Heavy-to-very-heavy rainfall events during July 05-16 resulted in severe flooding over Bihar and Assam and caused huge damage in the form of life and property. More than 90 lakhs people have been affected, and about 100 causalities have been reported in Bihar and Assam due to severe flooding. Results presented in this short communication highlight the importance of space-borne near real-time monitoring of flood events. It is reported that few districts of Assam and Bihar received cumulative rainfall in excess of 1200 mm from multiple heavy rainy events during July 05-16, 2019. Heaviest rainfall events were reported on July 06, 11 and 13. Few districts of Assam and Bihar experienced daily rainfall in excess of 300 to 400 mm during these heavy rainy days with peak hourly rainfall exceeding 50 mm at few synoptic hours. Discharge from Kosi and Brahmaputra rivers combined with heavy cumulative rainfall from multiple rainy episodes during July 05-16 resulted in severe flooding over Assam and Bihar causing losses to life and property.

Geospatial analysis of September, 2019 floods in the lower gangetic plains of Bihar using multi-temporal satellites and river gauge data

“…The intense precipitation leads to higher runoff, causing most of the rivers to overflow and flood low lying areas adjoining to the flood plains. The recurrent flooding displaces millions of people, impacts their livelihoods, besides causing loss of lives, livestock and critical infrastructure (Bhatt et al 2010;Singh et al 2011;Manjusree et al 2015;Mishra et al 2019;Tripathi et al 2019).…”

Examination of heavy flooding over the desert state of Rajasthan in India

“…Mishra () devised a rainfall monitoring technique by integrating multiple‐frequency observations from satellites to estimate heavy rainfall at fine temporal and spatial scales. The usefulness of this technique was validated by exploring the flood events of Kedarnath (Mishra and Srinivasan, ), Jammu and Kashmir (Mishra, ) and Tamilnadu (Mishra, ), Kerala (Mishra and Nagaraju, ) and Bihar and Assam (Mishra et al ., ).…”

“…Recent studies report a changed precipitation pattern over India, resulting in an increase in flooding events due to heavy rainfall events (Goswami et al ., ; Rajeevan et al ., ; Mishra and Liu, 2014; Mishra, 2019). The majority of states in India have experienced flood‐like situations in recent years (Mishra and Srinivasan, ; Mishra, , ; Mishra et al ., ; Mishra and Nagaraju, ; Ray et al ., ), and flooding due to heavy rainfall from multiple rainy spells has resulted in heavy losses and has affected millions of people.…”

Climate change quadruples flood‐causing extreme monsoon rainfall events in Bangladesh and northeast India

“…The mean rainfall in this region is primarily associated with the summer monsoon rainfall from June to September that contributes more than 70% of the total annual rainfall (Fahad et al, 2022). Owing to the exceptional mean rainfall of this region, extreme rainfall events are very frequent, causing flash floods and landslides in Bangladesh and northeastern India (Ahasan et al, 2010; Brouwer et al, 2007; Islam & Uyeda, 2007; Mahanta et al, 2013; Mishra et al, 2019; Shahid, 2011).…”