Monday, November 23, 2015

Chasing landslides in the Darjeeling Himalayas (1) - 22Nov2015

STH has over the years endeavored to maintain a historical record of the landslide activity in the Darjeeling-Sikkim Himalaya in this blog since our region happens to be one of the most landslide prone in the world.
In a bid to update our records we will carryout surveys of landslide areas and publish our findings here - they will not be technical documents rather just factual data to highlight the severity of landslides in this region, in a hope that this disaster form will get the importance that it deserves.

27th Mile Landslide

1. Coordinates: N 26°59.913´ E 088°25.898´
2. Elevn : 299m 
3. Date of activation: 01July2015 - triggered by heavy rain
4. Approx size (from Google Earth): 236m X 400m 
5. Likely impact :
National Highway (NH) 10 and possibly Teesta Low Dam Project (TLDP III)

Karmat Landslide

1. Coordinates: N 26°55.749´ E 088°25.782´
2. Elevn: 675m
3. Date of Activation: Not known
4. Approx size (from Google Earth): 374m X 586m 
5. Likely impact:
Road communication from NH10 to Latpanchar cinchona plantation, Sittong 1/2/3 villages.

Sittong (3) Landslide

1. Coordinates: N 26°56.074´ E 088°23.708´
2. Elevn: 1143m
3. Date of Activation/cause : July1999 - triggered by heavy rain 
4. Approx size (from Google Earth): 290m X 1332m 
5. Fatalities : 08 in 1999. 
6. Relocated : 11 families shifted to Namthing Pokhari by Kurseong block office.
7. Planning relocation due to instability : 4 families with 18 members
8. Impacted:
Many acres of orange orchards and broom plants in the area.

A Different Type of Disaster :
Sittong (1/2/3) village was known for its fine oranges which used to flood the market places of Darjeeling district in Dec/Jan and was one of the main cash crops for many of its citizens. During my visit there yesterday, I learnt that for the last 3 years or so the crop production had declined drastically and now in Nov 2015 they were expecting yields, 90% below their optimum levels.
I was told that a peculiar disease had infected all the orange trees, wherein they would start dying from the inside and then a certain insect would lay eggs on the fruit which would make it rot prematurely -  and all this happening more to orange orchards at the lower elevations.
Some villagers went so far as to tell me that in 2016, they would most probably not produce any oranges from Sittong.

My thanks to
Sachin Tamang of Kurseong (9832320738)
Dilkumar Rai of Shelpu, Sittong3 (9547280057)
MB Sarki of the Sittong landslide area (9832406234)
for their time and inputs.

Praful Rao,
Dist Darjeeling

Wednesday, November 18, 2015

International Mountain Day (11Dec2015)

For more on the above see here. As a part of the InMI we in Darjeeling will be observing International Mountain Day.

Praful Rao,
Dist Darjeeling

Tuesday, November 17, 2015

STH stormwatch (17Nov2015) : Update on the low position

As per IMD the well marked Low Pressure Area now lies off the Andhra Pradesh and North Tamil Nadu coast (see above).
Had it moved inland it would have weakened quickly - now that it is still in the Bay of Bengal, I hope it does not intensify further. The storm though not a depression or cyclone has caused enough fatalities and damage in Tamil Nadu already.

Praful Rao,
Dist Darjeeling

Thursday, November 12, 2015

Impact of humans on landslides : 14th Mile landslides (Kalimpong) in 2002 and now (2015).

The 14th Mile landslides (top) or sinking zone is one of the oldest in Kalimpong and has been featured in this blog earlier
Placed above are 2 Google Earth images of the same landslide zone of 2002 and 2015.
Both are photos were taken in January and the areas numbered 1 and 2 show significant increase in human habitation in the intervening 13yr period between the two photos.
Site 3 shows the 14th Mile landslides which are much bigger in the 2015 image even though we have had deficient rainfall in Kalimpong for 3 consecutive years from 2013 ie we are seeing an increase in landslides even though there is a decrease in precipitation (rainfall data of this region for the last three years is documented month-wise elsewhere in this blog).
Without being overly simplistic, as human activity grows along mountain crests, surface run-off of rain water from paved areas sharply increases the torrents of water charging the mountain streams or jhoras, leading to higher levels of erosion and landslides.
Increasingly, human activity is therefore emerging as a major cause of landslides in the mountains and is undoubtedly the main trigger for all fatal landslides that have taken place in Darjeeling-Sikkim in the recent past.
While it is well within our reach to control these actions and mitigate the landslides, neither the community nor the government (includes politicians) are bothered.

Praful Rao,
Dit Darjeeling

Saturday, November 7, 2015

STH stormwatch : Low Pressure forms in the Bay of Bengal - 07Nov2015

A Low Pressure Area has formed in the Bay of Bengal and as per IMD, it is likely to intensify into a well marked low pressure and then become a depression in the next 48hrs.

UPDATE on the storm (2100hrs) on 07Nov2015
IMD has upgraded the storm from a 'Low' to a 'Well Marked' low pressure area which will intensify into a depression in the next day or so

 UPDATE on the storm 08Nov2015
Track of storm is from JTWC

UPDATE (2) on the storm 08Nov2015
IMD has upgraded the storm from a 'well marked low' to a 'depression' in their midday weather bulletin. 
For anyone interested to check Chennai weather live see here 

UPDATE on the storm 09Nov2015

UPDATE (2) on the storm 09Nov2015
The depression intensified into a deep depression and crossed north Tamil Nadu coast at

UPDATE (last)  on the storm 10Nov2015 (evening)
The depression has moved inland and has weakened into a low pressure area and lies north of Tamil Nadu.

Praful Rao,
Dist Darjeeling

Friday, November 6, 2015

A tale of Two Cyclones : Cyclone 'Chapala' followed by Cyclone 'Megh' in the Arabian sea

Cyclones in the Arabian Sea are comparatively less frequent than those in the Bay of Bengal, and it is rare to see two cyclones in that area, riding bumper to bumper and heading towards the same region (ie the Yemen coast) all within a week!
Cyclone 'Megh' has now formed in the Arabian Sea, hard on the heels of 'Chapala' which dumped almost a decades' worth of rainfall in the deserts of war-torn Yemen a few days ago. The forecast track from JTWC show 'Megh' heading to the same region.

Praful Rao,
Dist Darjeeling

Thursday, November 5, 2015

Rainfall data Darjeeling and Sikkim Oct2015 and IMD End of Season Report

The SW Monsoons of 2015 have withdrawn from the country as a whole. October 2015 again was a month of deficient rainfall for the entire Darjeeling- Sikkim Himalaya.
No landslides were reported during this month.

Praful Rao,
Dist Darjeeling

Saturday, October 31, 2015

Good news for Darjeeling -Sikkim Himalaya : Landslide Prediction Study by Ulster University in early 2016.

Ulster University (UK) has secured funding for a new study focusing on landslide prediction in the Indian Himalayas, which will use novel techniques to help predict massive landslide disasters and save lives.
The team of researchers from Ulster University, and other collaborators, will use their expertise in sensor development, landslide physics and impacts of hazardous weather throughout the project. They will explore state of the art technical and functional requirements for a novel landslide prediction system using low-cost, high-density sensor networks and smart landslide prediction techniques.
India Education and Research Initiative (UKIERI) and is supported by the Department for Employment and Learning. It was secured in close collaboration with key project partners including the University of East Anglia, Indian Institute of Technology Delhi, India Institute of Technology Hyderabad and University College London.
Ulster University's Professor Gerard Parr said: "This specific study will focus on predicting massive landslides due to extreme weather events in remote mountainous areas in the Indian Himalayas, namely in the Darjeeling region where unfortunately landslides have historically claimed many lives and damaged infrastructure.
"The results of this study will not only help to underpin critical landslide prediction solutions for remote rural Indian communities but for other countries around the world, including the UK, where flooding and extreme weather conditions can result in landslides and also threaten human life, lifestock and economic infrastructures.
"We are delighted to have been successful in our bid for this Feasibility Study which builds on aspects of our previous research within the India-UK Advanced Technology Centre (IU-ATC), the largest ICT project of its kind between UK and India."
The project will be led by Professor Gerard Parr together with colleagues Professor Sally McClean, Professor Bryan Scotney and Professor Philip Morrow from the Information and Communications Research Group at Ulster University's Coleraine campus. They will be joined by Professor Stephen Hailes who is Chair of Wireless Systems and Deputy Head of Department of Computer Science at University College London, Prof Dave Petley (University of East Anglia- UEA) Pro-Vice Chancellor for Research and Enterprise at UEA and a world authority on Landslide Physics; Dr Christopher Kilburn (UCL) who is the Director of the Aon Benfield Hazard UCL Centre ; Professor Subrat Kar (Indian Institute of Technology New  Delhi) and Professor Uday Desai- Director of Indian Institute of Technology Hyderabad. 

Praful Rao,
Dist Darjeeling

Monday, October 26, 2015

Indian National Academy of Engineering (INAE) Round Table meeting on 'Landslide Risk Reduction' : 04Nov2015

As is known, Indian National Academy of Engineering (INAE), is the apex body for Engineering in the country.
Its Forum on Engineering Interventions for Disaster Mitigation is holding a one day Round Table 2 discussion on Landslide Risk Reduction on 04Nov2015.
The main thrust of the meeting will be on
  •  Large scale Landslide Hazard mapping for anticipation of landslide hazards and their mitigation, and 
  •  Science, Engineering and Innovation in Landslide Investigation, studies and management.
Venue : Central Road Research Institute(CRRI), New Delhi (near Okhla on the Delhi-Mathura highway.)

You can download the Abridged Recommendations (ii) Recommendations and (iii) The Backgrounder and the Basis Paper of the meeting here

Praful Rao,
Dist Darjeeling