The Pakistan Flood of August 2022: Causes and Implications

• Published in: Earth's future Vol. 11; no. 3
• Main Authors: Nanditha, J. S., Kushwaha, Anuj Prakash, Singh, Rajesh, Malik, Iqura, Solanki, Hiren, Chuphal, Dipesh Singh, Dangar, Swarup, Mahto, Shanti Shwarup, Vegad, Urmin, Mishra, Vimal
• Format: Journal Article
• Language: English
• Published: Bognor Regis John Wiley & Sons, Inc 01.03.2023; Wiley
• Subjects: Atmospheric models; Climate change; Climate change mitigation; Environmental risk; extreme precipitation; Extreme weather; flood; Flood risk; Floods; Global warming; Hydrologic models; Hydrology; Moisture effects; Pakistan flood; Precipitation; Risk reduction; Satellites; Soil conditions; Soil moisture; Stream discharge; Stream flow; Summer; Temperature; Wind; Bay of Bengal; Pakistan; South Asia
• ISSN: 2328-4277; 2328-4277
• DOI: 10.1029/2022EF003230

The risk of floods has increased in South Asia due to high vulnerability and exposure. The August 2022 Pakistan flood shows a glimpse of the enormity and devastation that can further rise under the warming climate. The deluge caused by the floods in 2022, which badly hit the country’s southern provinces, is incomparable to any recent events in terms of the vast spatial and temporal scale. The flood event is ranked second in human mortality, while this was the top event that displaced about 33 million people in Pakistan. Using observations and climate projections, we examine the causes and implications of the 2022 flood in Pakistan. Multiday (∼15 days) extreme precipitation on wet antecedent soil moisture conditions was the primary driver of the flood in August 2022. The extreme precipitation in August was caused by two atmospheric rivers that passed over southern Pakistan. Streamflow simulations from the multiple hydrological models show that multiday extreme precipitation was the primary driver of floods. Several flood‐affected stations experienced anomalously higher flow than the upstream stations. The 2022 Pakistan flood highlights the adaptation challenges South Asia is facing along with the substantial need for climate mitigation to reduce the risk of such events. Plain Language Summary The Pakistan flood of 2022 received a considerable attention. However, the causes and implications of the events have not been examined. Using observations, satellite data, and reanalysis products, we show that the event was caused by multiday extreme rainfall on wet antecedent conditions. The extreme rainfall was associated with the two atmospheric rivers that transported significant moisture from the Arabian Sea. The flood was primarily driven by the extreme precipitation and other factors (glacier‐melt) played a secondary role. Extreme precipitation is projected to increase in a warming climate, which highlight the strong need of adaptation and mitigation. Key Points The southern provinces of Pakistan received more than 350% of average precipitation in July and August based on the 2001–2021 mean Extreme precipitation event in August is associated with atmospheric rivers Multiday extreme precipitation was the primary driver of floods