The Oct 2023 Teesta Valley GLOF disaster gets its due recognition: An article published on the disaster in SCIENCE MAGAZINE

The GLOF sweeping past the Teesta bazar (W Bengal) on 04Oct2023. This drone photo by Praveen is certainly one of the most iconic images of a GLOF.

The SCIENCE MAGAZINE (https://www.science.org) is widely recognized as the world's most prestigious journal on science, publishing the very best in research across the sciences, with articles that consistently rank among the most cited in the world. It is published by the American Association for the Advancement of Science (AAAS), the world’s oldest and largest general science organization.
Dr Ashim Sattar (IIT Bhubaneshwer) is a glaciologist who has done a huge amount of research on the South Lhonak glacial lake and had almost predicted accurately the GLOF which occurred on 03/04Oct2023. I have quoted extensively from his write up earlier in this blog and had the good fortune of meeting him at Chitrey, in the Teesta valley last year when he was enroute to Gangtok, Sikkim.

With Ashim (left) on 21Feb2024 at Chitrey

In our brief interaction, he mentioned he was working with many world experts on a paper on the 03/04Oct2023 Teesta Valley GLOF disaster which I daresay was all but ignored by government and the media even  though it was the largest GLOF disaster in the Himalayas in the recent past.
Since then I have personally had many interactions with him, shared photographs of the GLOF and affected areas and discussed the impact at the many places we had visited while recording the GLOF.
Even though I am unaware of the technical details of the mammoth work that Ashim and all the associated scientists have put in, I know getting it published in Science Magazine was another huge challenge and it took months of meticulous work by Ashim with literally many emails being exchanged between all of us.
The full article published by SCIENCE MAGAZINE yesterday, is here (https://www.science.org/doi/10.1126/science.ads2659)
In addition, Dr Dave Petley, VC Univeristy of Hull (UK) who is one of the co - authors has published his synopsis of the whole article - which is here (https://eos.org/thelandslideblog/sikkim-glof-october-2023)
My grateful thanks to Dr Ashim Sattar and all the eminent scientists who devoted so much time and effort towards this article.

Praful Rao
SaveTheHills
savethehills@gmail.com
9475033744

Commemorating the 'Teesta Valley GLOF of 04Oct2023' with photos of the event and its aftermath.

A woman washes the money she recovered while scavenging for lost property in a flood affected area of Rangpo (Sikkim) on 06Oct2023 - photo credit Praveen

As I write, it is very early morning on 04Oct2024 and it was exactly at this time last year that I was up at my home in Kalimpong, trying to contact and verify with people, mainly in Sikkim, about whether a GLOF had actually taken place in the Teesta valley.
In the meantime my cellphone was receiving images and videos of the floods as the wall of water tore down the valley. Just verifying what was happening in order to report and record it accurately  kept me engaged the entire day and next, while my young friend and photographer Praveen Chhetri visited Teesta Bazar which the GLOF hit around 4am. He recorded the impact of the GLOF as it happened.
I did not know then that this process of recording the GLOF and its impact would keep us busy for an entire year but it has - and has required numerous visits to many parts of the Teesta valley including one trip made in Nov2023 to Chungthang where the 1200mw Sikkim Urja hydroelectric dam was destroyed by the GLOF.
What we have in this blog is perhaps the most comprehensive photographic record of what was the largest GLOF which took place in the Himalayas. Praveen and I certainly have hundreds of images, many videos and voice recordings of the interviews of affected people that we did during the course of the year.

    Interviewing an affected person who had lost everything to the GLOF - Rangpo (Sikkim), 06Oct2023.

This post, where I publish some photos is only to commemorate that momentous event which changed the lives of so many
Lest we forget...

Army personnel recovering buried vehicles at Bardang (Sikkim) on 06Oct2023. 22 army persons who were a part of a convoy were swept away by the GLOF here

Landslide affected areas of Naga, a village between Mangan(district headquarters, North Sikkim) and Chungthang in Nov2023 (telephoto image from opposite hill). The village was almost entirely evacuated during the monsoons of 2024.

A man crosses the Teesta river on a bamboo bridge at Toong, North Sikkim in Nov2023. The bridge connecting Chunthang to Mangan was torn down by the GLOF

GLOF affected areas between Chungthang and Lachen town where there was no impact of the Sikkim Urja dam burst. The scale of the devastation caused by the GLOF alone is apparent in the photo - photo courtesy Dathup, Lachen.

GLOF eroded parts of NH10 between Teesta bazar and Melli in Oct 2023. With the Teesta river running 4-5m above the pre-GLOF levels, the erosion of NH10 increased remarkably in 2024.

Debris and vegetation which the GLOF had dumped on top of the NHPC Stage V 510MW dam at Dikchu, SIkkim. The Teesta river 'over toppled ' ie went over the dam at this site.

Tree stumps and debris inside the NHPC Stage VI dam at Sirwani, Singtam (Sikkim), Nov2023

Vehicles strewn around like battered toys, on the banks of the Teesta at Singtam (Sikkim).

Part of Teesta town (Krishnagram or Bhasuwa) literally sliding slowly into the river - Sep2024

A marooned COVID hospital on the banks of the Teesta and Rangeet rivers at Tribeni, (Darjeeling district) - Sep2024. There is no road access to the hospital with the Teesta river having kept large parts of the access road submerged after the GLOF.

Rangpo town in Sept24. One year after the GLOF, parts of the town are still trying to recover. The river still flows uncomfortably close to the town and the police checkpost (green roofed structure on the top left is literally tilting into the river.

Undoubtedly one of the most iconic images of a GLOF.

Drone image taken by Praveen at around 11.00am on 04Oct2023 from the Teesta bridge when the GLOF was passing thru the area. As can be seen much of the Teesta bazar was already submerged.

Documentation of parts of the above report was supported by Royal Enfield, as part of their Social Mission Initiative


With
Praveen Chhetri (9733185815)

Praful Rao
SaveTheHills
9475033744
savethehills@gmail.com

Impact of the Oct 2023 Teesta Valley GLOF: Photosurvey of the Geil khola - Likhu bhir section of NH10 on 23Aug2024

NH10 winds itself along the banks of the Teesta river. Gangtok and Kalimpong are towards the right hand side whereas Siliguri is towards the left.

The monsoons have been playing truant in our region recently. Broadly speaking, after the heavy rains in Jun2024, going into mid July, we had less rain towards the latter part of July2024 and deficient rains in August2024.
The deficient rainfall is worrisome in terms of water availability in our region but has allowed the NH10 repairs to progress and yesterday (23Aug2024) the highway was declared open once more:

I photographed the Geil Khola - Likhu Bhir section on 23Aug2024 and have placed several large images of this area which has been one of the most troublesome part of NH10 for maintenance after the Oct 2023 Teesta Valley GLOF in the hope that it may benefit  researchers, engineers and especially lay people who use the highway. You might even like to compare these recent images with our report of the same area done on 18Oct2023.

With the river flowing 4-5m above pre-GLOF levels, it is now running close to the level of the road (and also closer to the IRCON tunnel as well), increasing erosion of the road and the maintenance problems. Teesta bridge is in the top right hand corner.

This image clearly shows how close the river is to Teesta bazar (top right hand corner) of which several areas are sinking and the level of the river between Rabi jhora (see map) and the Teesta bridge thru which the Darjeeling- Kalimpong is routed.

Notice the level of the Teesta as it hugs the NH10 in between Geil Khola (extreme right) and the settlement (29Mile or Baluatar) at the center of the photo.

Section of NH10 between Baluatar (settlement on the right hand side) and Teesta Low Dam Project III (TLDPIII), left top.

The Likhu Bhir section of the NH10 - perhaps the most troublesome part for maintenance as well as traffic jams.

Geil khola - Likhu Bhir - Teesta Bridge (top right) section. The post -GLOF Teesta river is flowing bank to bank even with deficient rainfall in Darjeeling -Sikkim Himalaya over the past two weeks. We still have a month or more of rains left.

Documentation of the above report supported by Royal Enfield, as part of its Social Mission Initiative

Praful Rao
SaveTheHills,
Darjeeling-Sikkim Himalaya
savethehills@gmail.com
9475033744

Rainfall data of July 2024 of some towns in Sub-Himalayan W Bengal and Sikkim

IMPACT OF THE JULY 2024 RAINS AT TEESTA BAZAR:
Some young men at Teesta bazar had started a two wheeler repair business in this shop on the Darjeeling-Kalimpong road after they shovelled out all the sand and debris brought in by the 04Oct2023 disaster (notice the damaged ceiling fans). The rains of July2024 put an end to their business venture and dreams when the Teesta river, flowing in the vicinity and almost at the same level flooded their shop again during heavy rains.

Rainfall normally peaks in July during the monsoons after which the rainfall gradually declines in August and Sept with the monsoons normally exiting our region in October.
As is clearly visible from the top data, rainfall was heavier in the Dooars area and foothills of Kalimpong district (and Bhutan hills).
IMPACT
The amount and intensity of rainfall impacted road communication a lot with NH10 and the Darjeeling - Kalimpong road being closed OFF and ON thru the month.

Even Rohini road to Darjeeling from Siliguri was closed for some time on 02Jul2024

                                Landslide near Loreto School, Darjeeling - 05July2024

INFACT NH10, WHICH HAD CLOSED ON 01JULY2024, COULD NOT BE RE-OPENED FOR TRAFFIC UNTIL 31JULY2024 - WHICH WAS THE LONGEST DURATION THAT THE HIGHWAY WAS CLOSED CONTINUOUSLY EVER - ALL DUE TO THE TEESTA VALLEY GLOF OF 04OCT2023.

Landslide on NH10, at Andheri, near Rangpo on 16July2024.

A low pressure area in the Bay of Bengal which brought in a drier spell of weather in our region after the heavy rains in the first half of July2024.

My thanks to all our What's App group ('Hazard Alerts') members whose images and stories I have used in this post

Praful Rao
with
Yukta Acharya

SaveTheHills
Kalimpong district
Darjeeling-Sikkim Himalaya
savethehills@gmail.com
9475033744

Rainfall data of June 2024 of some towns in the Sub Himalayan W Bengal (SHWB) and Sikkim.

Even though the SW monsoons set in our region on 31May2024, the Darjeeling-Sikkim Himalaya started receiving significant rainfall only after the 10Jun2024.

IMD had issued appropriate warnings and press releases which attributed the heavy rain to 'a cyclonic circulation lying over northeast Assam & neighbourhood in lower tropospheric levels. and a trough which runs from East Uttar Pradesh to Nagaland'.

This weather system persisted for an inordinately long period resulting in a RED WARNING for heavy rain in our region which lasted for almost 10 consecutive days in mid Jun2024 and which caused a delay in the progress of the monsoons.
A senior meteorologist, I talked with said he had never witnessed this sort of phenomenon in his entire professional career:

Satellite image post in 'Hazard Alerts', our What'sApp group.

A typical rainfall pattern of thundershowers which are more often the norm in our region these days is shown below - these are sharp, heavy bursts of rain from Cumulonimbus (CB) clouds.

IMPACT

 

What is clear from the rainfall in June2024 is

• The heaviest rainfall took place in the plains of the Dooars with Alipur Duar clocking the highest rainfall.
  
• The foothills (Jhallong) also receive very heavy rain, some 4000mm annually and both our alternate roads (NH717A and the Gorubathan-Lava roads) to NH10 largely pass thru these foothills.
• Sikkim received more rain than Darjeeling and Kalimpong districts
• Even with this rain, many of our roads, especially NH10 are in tatters and unfortunately, things are not going to improve at least for the next 2 months or more - obviously, the Oct 2023 GLOF is the single most important factor causing this chaos.
  

While in the airforce many years ago, I was posted to Air Force Station Hashimara (which is very close to Alipur Duar) where receiving 200mm of rainfall overnight during the monsoons was not abnormal and the best part was NOTHING USED TO HAPPEN when we had such heavy rain. The river Torsa which flows close by never flooded and the drainage in the area used to swiftly take away the excess storm water into canals.
But we saw what happened in Mangan (North Sikkim), when they received 220mm rain on 12Jun2024 - there were many landslides, 6 people died and 1500 tourists were stranded in North Sikkim.
Bottom line: Our mountains are just too fragile and sensitive compared to the plains and we have to take care of them.

Praful Rao
with
Yukta Acharya

Kalimpong district
Darjeeling-Sikkim Himalaya
savethehills@gmail.com
9475033744