2023 Sikkim flash floods
{{Short description|Natural disaster in Northeast India}}
{{Infobox flood
| image location = India SK.svg
| image name = The state of Sikkim within India
| name = 2023 Sikkim flash floods
| duration = 4–5 October 2023
| total damages = 15 bridges, one hydroelectric dam destroyed
| total fatalities = 92+
| areas affected = {{ubl|Sikkim districts|Mangan, Gangtok, Pakyong, and Namchi|West Bengal districts|Cooch Behar, Jalpaiguri, Darjeeling, and Kalimpong}}
| cause = Outburst of the South Lhonak lake due to heavy rainfall
}}
On 4 October 2023, heavy rains caused the glacial South Lhonak lake in Sikkim, a state in northeastern India, to breach its banks, causing a glacial lake outburst flood.{{Cite news |last1=Choudhury |first1=Subrata Nag |last2=Hussain |first2=Zarir |date=4 October 2023 |title=Floods in India's Sikkim state leave 10 dead, 82 missing |language=en |work=Reuters |url=https://www.reuters.com/world/india/nearly-two-dozen-indian-troops-missing-after-flash-flood-ani-2023-10-04/ |access-date=4 October 2023 |archive-date=4 October 2023 |archive-url=https://web.archive.org/web/20231004201658/https://www.reuters.com/world/india/nearly-two-dozen-indian-troops-missing-after-flash-flood-ani-2023-10-04/ |url-status=live }} The flood reached the Teesta III Dam at Chungthang at midnight, before its gates could be opened, destroying the dam in minutes.{{Cite web |date=4 October 2023 |title=Sikkim dam washed away in 10 minutes after flash flood: Official |url=https://www.hindustantimes.com/cities/others/sikkims-biggest-hydro-project-suffers-massive-damage-in-flash-flood-101696420752235.html |access-date=4 October 2023 |website=Hindustan Times |language=en |archive-date=4 October 2023 |archive-url=https://web.archive.org/web/20231004161014/https://www.hindustantimes.com/cities/others/sikkims-biggest-hydro-project-suffers-massive-damage-in-flash-flood-101696420752235.html |url-status=live }} Water levels downstream in the River Teesta rose by up to {{convert|20|ft}}, causing widespread damage.{{Cite news |date=4 October 2023 |title=8 dead, 22 army men among 48 missing as flash flood wreaks havoc in Sikkim |work=The Tribune India |url=https://www.tribuneindia.com/news/india/lake-burst-at-sikkims-chungthang-flash-flood-alert-as-teesta-river-water-levels-rise-550329 |access-date=4 October 2023 |archive-date=4 October 2023 |archive-url=https://web.archive.org/web/20231004230222/https://www.tribuneindia.com/news/india/lake-burst-at-sikkims-chungthang-flash-flood-alert-as-teesta-river-water-levels-rise-550329 |url-status=live }}
It was the deadliest flood in the area after the 1968 Sikkim floods when around 1000 people were killed.{{Cite news |date=9 October 2023 |title= Meer lichamen gevonden na overstromingen en dijkdoorbraak India, 74 doden |work=NOS |url= https://nos.nl/artikel/2493456-meer-lichamen-gevonden-na-overstromingen-en-dijkdoorbraak-india-74-doden |access-date=9 October 2023|language=nl}}
Background
The South Lhonak Lake is a moraine-dammed lake fed by the meltwater of the Lhonak glacier. It was first seen in CORONA satellite images from 1962 as a supraglacial lake. Landsat MSS images show that it became a separate lake by 1977, with a surface area of {{convert|17|ha|lk=on}}. In four decades, as the glacier retreated {{convert|1.9|km}}, the lake swelled in size, covering nearly {{convert|100|ha|0}} by 2008.{{Cite journal |last1=Babu Govindha Raj |first1=K. |last2=Remya |first2=S. N. |last3=Vinod Kumar |first3=K. |date=10 February 2013 |title=Remote sensing-based hazard assessment of glacial lakes in Sikkim Himalaya |url=https://www.jstor.org/stable/24089638 |journal=Current Science |volume=104 |issue=3 |pages=359–364 |jstor=24089638 |access-date=6 October 2023 |archive-date=14 May 2023 |archive-url=https://web.archive.org/web/20230514050612/https://www.jstor.org/stable/24089638 |url-status=live }} It was identified as potentially at risk of causing glacial outburst floods, and in 2018 pipelines were carried up by yak and installed to pump water out of it.{{Cite web |last=Singh |first=Jyoti |date=2018-09-26 |title=Glacial lake flood keeps disaster managers on toes in Sikkim |url=https://www.thehindubusinessline.com/news/science/glacial-lake-flood-keeps-disaster-managers-on-toes-in-sikkim/article25048865.ece |access-date=2023-10-06 |website=BusinessLine |language=en}} Sentinel-1A images from 28 September 2023 showed the lake covering an area of {{convert|167.4|ha}}.{{Cite web |date=2023-10-05 |title=Sikkim flash floods {{!}} Over half the area drained: ISRO satellite images show before, after of South Lhonak lake |url=https://indianexpress.com/article/india/sikkim-flash-floods-south-lhonak-lake-before-after-satellite-image-8969255/ |access-date=2023-10-06 |website=The Indian Express |language=en |archive-date=2023-10-06 |archive-url=https://web.archive.org/web/20231006040209/https://indianexpress.com/article/india/sikkim-flash-floods-south-lhonak-lake-before-after-satellite-image-8969255/ |url-status=live }}
Before the flood, scientists and authorities were working on installing an early warning system for glacial floods from the lake.{{Cite news|date=2023-10-06|title=Exclusive: Indian glacial lake that flooded was poised to get early warning system|url=https://www.reuters.com/world/india/india-lake-that-flooded-was-poised-get-early-warning-system-2023-10-05/|access-date=2023-10-06|website=Reuters|language=en|archive-date=2023-10-06|archive-url=https://web.archive.org/web/20231006001404/https://www.reuters.com/world/india/india-lake-that-flooded-was-poised-get-early-warning-system-2023-10-05/|url-status=live}}
The flood
In early October 2023, a cloudburst caused Sikkim to receive more than double its normal rainfall; between 3 and 4 October alone, the state received five times the usual precipitation. The South Lhonak burst its shores, causing a flash flood. Satellite images from the Indian Space Research Organisation's RISAT-1A show that the lake's surface area shrunk by more than {{convert|100|ha|0}}. Based on a warning from the Indo-Tibetan Border Police at midnight, the operators of the Teesta III Dam at Chungthang rushed to open the dam's gates, but were too late; the flood quickly destroyed the dam, as well as the bridge to its 1200-MW hydroelectric powerhouse, which was submerged.
Water levels downstream in the River Teesta subsequently rose by {{convert|15|to|20|ft}}, flooding many areas in Mangan, Gangtok, Pakyong, and Namchi districts in Sikkim, and Kalimpong, Cooch Behar, Jalpaiguri and Darjeeling districts in West Bengal.{{Cite news |last= |date=2023-10-04 |title=Sikkim flood {{!}} 10 dead, 22 army men among 82 missing as flash flood wreaks havoc; PM Modi dials CM Tamang |language=en-IN |work=The Hindu |url=https://www.thehindu.com/news/national/other-states/several-dead-and-missing-as-flash-flood-wreaks-havoc-in-sikkim-pm-modi-dials-cm/article67382079.ece |access-date=2023-10-06 |issn=0971-751X |archive-date=2023-10-06 |archive-url=https://web.archive.org/web/20231006012904/https://www.thehindu.com/news/national/other-states/several-dead-and-missing-as-flash-flood-wreaks-havoc-in-sikkim-pm-modi-dials-cm/article67382079.ece |url-status=live }} The flood also went onwards to Bangladesh, where it affected hundreds of villages along the Teesta River and Char areas.
Fifteen bridges across the state were washed away, and the north of the state, including the capital Gangtok, was cut off from the rest of India as parts of National Highway 10 collapsed. Three thousand tourists were stranded across the state.{{Cite news |date=2023-10-05 |title=Sikkim: Race against time to save 102 missing in India floods |language=en-GB |work=BBC News |url=https://www.bbc.com/news/business-66997995 |access-date=2023-10-06 |archive-date=2023-10-05 |archive-url=https://web.archive.org/web/20231005221406/https://www.bbc.com/news/business-66997995 |url-status=live }} Towns and cities like Chungthang, Dikchu, Singtam, Rangpo, Melli, and Teesta Bazaar were very heavily damaged.
Relief operations
The government of Sikkim declared the flood a disaster, and the Indian central government released ₹48 crore ($5.76 million) in disaster relief funds.{{efn|Based on an exchange rate of 1 USD
Fourteen people were believed to be trapped inside the tunnels of the destroyed Teesta III Dam; a 60-strong team of the National Disaster Response Force — including scuba divers — was assembled to rescue them.{{Cite web |date=2023-10-06 |title=Sikkim floods: NDRF faces great unknown in bid to save 14 trapped in tunnels |url=https://www.hindustantimes.com/india-news/sikkim-floods-ndrf-faces-great-unknown-in-bid-to-save-14-trapped-in-tunnels-101696533026443.html |access-date=2023-10-06 |website=Hindustan Times |language=en |archive-date=2023-10-05 |archive-url=https://web.archive.org/web/20231005235824/https://www.hindustantimes.com/india-news/sikkim-floods-ndrf-faces-great-unknown-in-bid-to-save-14-trapped-in-tunnels-101696533026443.html |url-status=live }}
Casualties
{{update section|date=October 2023}}
At least 40 people were killed and 22 injured, while 75 were reported missing as of 6 October.{{Cite news |last1=Choudhury |first1=Subrata Nag |last2=Ahmed |first2=Aftab |date=2023-10-06 |title=Death toll rises to 40 after glacial lake flooding in Indian Himalayas, dozens still missing |language=en |work=Reuters |url=https://www.reuters.com/world/india/least-40-killed-after-glacial-lake-flooding-indian-himalayas-officials-2023-10-06/ |access-date=2023-10-06 |archive-date=2023-10-06 |archive-url=https://web.archive.org/web/20231006070928/https://www.reuters.com/world/india/least-40-killed-after-glacial-lake-flooding-indian-himalayas-officials-2023-10-06/ |url-status=live }} By 18 October, 92 were confirmed dead, with more bodies being retrieved.{{Cite web |last=Lama |first=Prawesh |date=2023-10-17 |title=As Sikkim rescue op winds down, the search continues for local hero |url=https://www.hindustantimes.com/india-news/as-sikkim-rescue-op-winds-down-the-search-continues-for-local-hero-101697567152395.html |access-date=2023-12-02 |website=Hindustan Times |language=en}} Among the missing were 23 Indian Army personnel, of whom seven were subsequently found dead and one rescued alive.{{Cite web |date=4 October 2023 |title=Sikkim Flash Floods Updates: One out of 23 missing Army personnel rescued |url=https://www.hindustantimes.com/india-news/flash-flood-alert-sikkim-teesta-river-cloudburst-live-updates-4th-october-2023-101696390912870.html |url-status=dead |archive-url=https://web.archive.org/web/20231004185500/https://www.hindustantimes.com/india-news/flash-flood-alert-sikkim-teesta-river-cloudburst-live-updates-4th-october-2023-101696390912870.html |archive-date=4 October 2023 |access-date=4 October 2023 |website=Hindustan Times |language=en}}{{Cite web |date=2023-10-06 |title=Sikkim flood: Death toll rises to 25; 'explosive, firearms' warning issued |url=https://www.hindustantimes.com/india-news/sikkim-flood-death-toll-rises-to-22-army-issues-explosive-firearms-warning-101696587365494.html |access-date=2023-10-06 |website=Hindustan Times |language=en |archive-date=2023-10-06 |archive-url=https://web.archive.org/web/20231006103605/https://www.hindustantimes.com/india-news/sikkim-flood-death-toll-rises-to-22-army-issues-explosive-firearms-warning-101696587365494.html |url-status=live }} One of the dead soldiers was found floating in the Teesta in Nilphamari, Bangladesh; the Border Guard Bangladesh handed over the body to the Indian officials through a flag meeting.{{cite web |title=Indian soldier's body found in Teesta handed over to BSF |url=https://www.dhakatribune.com/amp/bangladesh/nation/327225/indian-soldier%E2%80%99s-body-found-in-teesta-handed-over |website=Dhaka Tribune |date=6 October 2023 |access-date=6 October 2023 |archive-date=7 October 2023 |archive-url=https://web.archive.org/web/20231007063854/https://www.dhakatribune.com/amp/bangladesh/nation/327225/indian-soldier%E2%80%99s-body-found-in-teesta-handed-over |url-status=live }} One child was killed and six injured in the neighbouring state of West Bengal when a mortar shell carried downstream from Sikkim exploded after being picked up by locals.
Notes
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References
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{{2023 floods}}
{{Disasters in India in 2023}}
{{DEFAULTSORT:Sikkim flash floods, 2023}}
Category:2023 disasters in India
Category:October 2023 in India