Friday, September 18, 2020

A picture which is our shame : a spring in Kalimpong


 As is known, springs all over the Himalayas are fast drying up and I have been involved in several attempts to rejuvenate springs in Kalimpong in the past (see 1 and 2).
It is therefore shocking to see the condition of many of springs from which so many draw their drinking water, this is just one example.

Praful Rao,
Kalimpong district
Darjeeling Sikkim Himalayas

Sunday, September 13, 2020

Landslide Report 3 (Kalimpong) - Sep2020

Continuing with the landslide surveys (See Report 1 and Report 2 in this blog)  around Kalimpong town, on 09Sep2020, we went to the north eastern sector of Kalimpong along Reshi Road upto ALGARAH. This road is of strategic importance to India since much of the logistics for the Indian army in East Sikkim (opposite Doklam) goes thru this road. Also in case of NH10 being blocked, this road, via Lava/Gorubathan serves as the alternate route to Siliguri.
Regarding the survey:
  • Besides the landslide/subsidence zones mentioned below, what was very evident was the serious deterioration in the condition of the Kalimpong -Algarah section of Reshi road with numerous sinking areas visible on many parts of the road, where another heavy shower or two could result in collapse of the road at multiple places.
  • What should be also noted here is that the entire region has many natural springs and jhoras which during heavy rain causes a lot of erosion and landslides in the area.
  • STH has recorded the extreme rainfall events of AUGUST 2020 and their effects in earlier posts (see 1 and 2). Further the rainfall of August 2020 is also available in this blog. All the landslides recorded below were the result rainfall during the extreme rainfall events.
GHATEY KHOLA subsidence

Coordinates: 27° 4'42.00"N, 88°29'50.88"E
Size of subsidence of road : approx 45m in length
During periods of intense rain, Ghatey Khola is notorious for causing landslides in this area since the runoff from the entire populated areas at the crest of the hill finds its way into this drain.
14th Mile sinking zones
The 14th mile sinking areas have been featured in this blog numerous times (see 1 and 2) and are one of the oldest landslide zones in Kalimpong. During the heavy rains of August 2020, these areas were re-activated at almost the same locations causing large portions of the Kalimpong- Algarah road (Reshi Road) to subside.
No other damage to farmland or infrastructure was observed.


Sinking areas of Algarah town
Algarah town is approx 15 kms NE of Kalimpong and has a long history of landslides. I had visited the area some years ago and marked out the sinking areas (above). WIth less rainfall in the past few years, the landslide and sinking zones had also diminished. This year with the intense rains that we have had, the hotspots have re-emerged and perhaps the most crucial one is the one in LAMA WARD which is located in the centre of Algarah town.

Coordinates: 27.1172° N, 88.5837° E
Landslide at HART spring, Dr Graham's Homes, Kalimpong

Coordinates: 27° 4'56.22"N, 88°29'48.48"E 

Photo credits: Ms Shreya Gurung

Praful Rao,
Kalimpong district
Darjeeling- Sikkim Himalaya

Sunday, September 6, 2020

Rainfall data of some towns in the Darjeeling- Sikkim Himalaya - AUGUST 2020

 Surprisingly:
  • Darjeeling town had less rain than Kalimpong town.
  • Sikkim rainfall (all 4 districts) was much less than that of Kalimpong and Darjeeling.
The New Normal : Intense bursts of rain in overnight thundershowers

Graphs from AWS of SaveTheHills show the pattern of rainfall at Kalimpong on 05/06Aug2020 and 26/27Aug2020. In both cases, thundershowers commenced in the late evening or night and got over within a couple of hours with instantaneous rainfall intensities going upto 252mm/hr on 05Aug.

Did we have a cloud burst on 05Aug2020?
Even though we cannot prove it, I do believe we had one. Rainfall intensities reached never before levels of 252mm/hr and the event caused major damage to roads in Kalimpong and infrastructure in W Sikkim.

And it is not as if we have not had cloudbursts earlier
STH has already recorded the extreme rainfall events of AUGUST 2020 and their effects in earlier posts (see 1 and 2).

My thanks to Ms Shreya Gurung for compiling the rainfall data.

Praful Rao
Kalimpong district
Darjeeling-Sikkim HImalaya

 

Tuesday, August 25, 2020

All about a sleek, shiny young visitor: Lucans (Odontolabis) gazella(Odontolabis) OR a Oriental Stag beetle

Photo credit : Ms Maya Rao
Last evening this winged visitor literally barged into our home just as it became dark. And each year, around this time, one or two of these stag beetles stray in; they are looking around for a consort, a quick marriage perhaps, then to vanish again for a year or so.
And we feature this wonderful creature in our blog because the stag beetle ALSO is among our vanishing species.
The reason is obvious: human activity.
These creatures literally spend all their lives, whether as beetles or as larvae in damp, warm forests and inside rotting wood or logs and when we remove forests and set fire to our fields, we destroy their habitats. Climate change is another big factor where excessive dry or wet weather can kill the larvae in the soil.
Many of the species are red listed all around the world and have gone extinct in many European countries. I have modified the life cycle drawing of the stag beetle and placed it below:

Praful Rao,
Kalimpong
Darjeeling-Sikkim Himalaya

Saturday, August 22, 2020

The New Normal: Extreme Rain (19/20Aug - Kalimpong)

 This image was posted in 'HAZARD ALERTS' our WhatsApp group at around 8.15pm on 19Aug2020


 
Other places of damage
  • Topkhana (near CST - ward no 7)
  • Upper Gairigaon (Painyun), Algarah.
  • Soureni (near Algarah)

My thanks to all who contributed with the photos and information.

Praful Rao
Kalimpong district
Darjeeling - Sikkim

Monday, August 10, 2020

Reporting an extreme event in the Darjeeling - Sikkim Himalaya (05Aug-06Aug2020)

RAINFALL DATA (24hrs) in Darjeeling- Sikkim -06Aug2020
W Bengal
Kalimpong - 106, Darjeeling - 99.4, Kurseong - 13
Sikkim
Gangtok - 59.2, Khanitar -119.4, Mangan - 104.2, Singhik - 130.8, Gyalsing - 83.6, Damthang - 82
Much of the rain was very high intensity - and came down within a couple of hours

CLOUD IMAGE AND RAINFALL CHARACTERISTICS OF 05/06AUG2020

What is apparent from the above graph and the AWS chart is the intensity of the rainfall - which peaked within hours to an incredible 252mm/hr at Kalimpong resulting in massive volumes of surface runoff from paved areas of urban centres. Videos of torrents of water gushing into residential areas, shops and flooding streets in Darjeeling, Kalimpong and Gangtok went viral. The intensity of the rain was ascribed to vertical buildup of the clouds - reaching well into the stratosphere with cloud top temps being -80 deg C.
While this sort of rainfall data for other towns is not available, similar scales of damage has been widely reported from Darjeeling, Kalimpong and Sikkim.

IMPACT AND DAMAGE FROM THE STORM

WEST BENGAL
Kalimpong suffered a fatality wherein a heavily swollen stream during the downpour in Lamini Gaon, Chota Bhalukhop swept away a 10yr old boy. This area lies in the western face of the Kalimpong ridge line. The body was recovered 3 days later.
A bridge in Dungra village (which lies below the town, on the eastern face of Kalimpong town) was washed away in the deluge
Many subsidences and landslides were reported on NH10 which is a vital link from
Siliguri to Gangtok. Most occurred between Teesta bazar and Coronation bridge.
 
SIKKIM - River Rangeet's Rampage 

Rangeet river is the biggest tributary of the Teesta river originating partly in West Sikkim. Older residents of Legship a town on the banks of the river in W Sikkim, recall that the last time the river was in full spate was during the Oct 1968 disaster.

Special thanks to Mr Mukesh Sharma (Kalimpong) for his inputs and photos.

Praful Rao
Kalimpong district
Darjeeling-Sikkim Himalaya

 

Monday, August 3, 2020

Landslide Report 2 (Kalimpong) July 2020 - contd

Landslide 4
I was with Prof Indira Lepcha (2nd from L) and a group of Geography Dept Students of North Bengal University in Feb2020 at this site in Lower Chibo area of Kalimpong. At that time the slide near the jhora was much smaller
Toe erosion at the same spot on 27July2020 has caused a much bigger slide now even though the road
is quite intact.
Location: Lower Chibo, Kalimpong
Coordinates: 27°03.077´N 088°26.732´E
Elevation: 923m
Date of Occurrence: 27July2020.
Landslide type: Debris
Size: Large (size of a 3 storey building)
Cause of Landslide: Heavy rainfall and toe erosion
Damage:
No apparent damage but if further slippage occurs the slide may block the jhora, forming a small landslide dam
Rainfall: 06July -109mm, 23Jul - 62.8mm, 27Jul - 88mm

Landslide 5
Location: Chitrey, Kalimpong district
Coordinates: 27°03´51.09"N 088°25´42.20"E
Elevation: 277m
Date of Occurrence: 27July2020.
Landslide type: Debris
Size: Large (size of a 3 storey building)
Cause of Landslide: Heavy rainfall
Damage:  Chitrey lies on NH10 and is where the road bifurcates to Sikkim and Kalimpong. The landslide here was troublesome and active below the road several years ago because of toe erosion by the Chitrey jhora. It has somehow remained dormant.
This slide from above the road was activated on 27Jul and threatens to cut off Kalimpong and SIkkim on NH10.
Rainfall: 06July -109mm, 23Jul - 62.8mm, 27Jul - 88mm

Landslide 6

          Signatures of some of the people of 3rd Mile who are affected by the landslides

Location: Lower Tashiding (3rd Mile) Kalimpong district
Coordinates: Between 27°03.721'N 088°26.214'E  and 27°03.694'N 088°26.346'E 
Elevation:
615m to 687m
Date of Occurrence:
27July2020.
Landslide type:
Debris
Size:
Villagers estimate approx 300m of farmland and populated areas maybe subsiding.
Cause of Landslide:
Erosion during heavy rain by the 6th Mile and Gurudev jhoras (mountain rivulets) which gets charged by the large runoff from urban areas (Kalimpong town) at the crest. This subsidence is not new but has been accelerated by the heavy rains of Jun/Jul2020.
Damage:
As per villagers I talked to, approx 40 homes are affected, along with farmland at the 3rd Mile area are affected. Also State Highway 12 which connects Teesta Bazar to Kalimpong is likely to be affected at the 3rd Mile area due to its proximity to the subsiding areas.
Rainfall: 06July -109mm, 23Jul - 62.8mm, 27Jul - 88mm

Unverified Damage Reports

Praful Rao
Kalimpong district
Darjeeling-Sikkim Himalaya