Abstract
Chandmari Hill lies in Gangtok City in the Himalayan Mountain Ranges of Northeast India. The Himalayas are particularly prone to landslides due to complex geology combined with high tectonic activity, steep slopes, and heavy rainfall. Chandmari Hill has experienced a significant number of landslides, both rainfall and earthquake triggered, during the past several decades. Recently, the Government of India commissioned Amrita University to develop and deploy a landslide early warning system at Chandmari Hill. During the initial phase of the deployment, we conducted walkover surveys at Chandmari Locality, which comprises a large portion of Chandmari Hill. We also extracted and tested soil samples, drilled a 33.5 m borehole, and analyzed rock cores from the borehole. We present the results of laboratory soil tests and use these results in mathematical models. We examine all landslides (rainfall-triggered and earthquake-induced) recorded at Chandmari Locality during the past five decades. Simple calculations demonstrate that when the input parameters of the models mimic the field conditions precursory to an actual landslide, the factor of safety of the slope is less than unity. Gangtok City lies close to the Main Central Thrust, MCT2, which separates the gneissic rocks of the Paro/Lingtse Formation from the mica schists of the Daling Formation. Our field investigations revealed that at Chandmari Locality, gneissic rock overlies highly weathered mica schist. We postulate that surface runoff infiltrates through fractures in the overlying gneiss and results in an extrusion of the finer micaceous material, leading to subsidence which is routinely observed during the monsoon season. During torrential rains, rainwater infiltration causes the sliding of the soft micaceous bands underlying the gneissic rock, leading to rockslides at the hill. We suggest that similar processes are responsible for the frequent and widespread occurrences of landslides and subsidence observed throughout the region.
The original version of the chapter was revised: For detailed information please see correction. The correction to this chapter is available at https://doi.org/10.1007/978-3-319-53483-1_64
Change history
20 May 2017
In Chapter “Challenges of Real-Scale Production with Smart Dynamic Casting”, low-resolution Figure 4 is replaced with high resolution, Figure 5 is replaced with new figure and Figure 6 and the graph near are positioned as per the standard.
References
Anbarasu K, Sengupta A, Gupta S, Sharma SP (2010) Mechanism of activation of the Lanta Khola landslide in Sikkim Himalayas. Landslides 7(2):135–147
Arora KR (2003) Soil mechanics and foundation engineering. Standard Publishers Distributors, Delhi
Basu SR, De SK (2003) Causes and consequences of landslides in the Darjeeling-Sikkim Himalayas, India. Geographia Polonica 76(2):37–52
Bhasin R, Grimstad E, Larsen JO, Dhawan AK, Singh R, Verma SK, Venkatachalam K (2002) Landslide hazards and mitigation measures at Gangtok, Sikkim Himalaya. Eng Geol 64(4):351–368
Bhattacharyya K (2010) Geometry and kinematics of the fold-thrust belt and structural evolution of the major Himalayan fault zones in the Darjeeling–Sikkim Himalaya, India. Ph.D. thesis, University of Rochester, Rochester, USA
Chakraborty I, Ghosh S, Bhattacharya D, Bora A (2011) Earthquake induced landslides in the Sikkim-Darjeeling Himalayas—an aftermath of the 18th September 2011 Sikkim earthquake. Geological Survey of India, Kolkata
Dubey CS, Chaudhry M, Sharma BK, Pandey AC, Singh B (2005) Visualization of 3-D digital elevation model for landslide assessment and prediction in mountainous terrain: a case study of Chandmari landslide, Sikkim, Eastern Himalayas. Geosci J 9(4):363–373
Duncan JM, Buchignani AL, De Wet M (1987) An engineering manual for slope stability studies. Virginia Polytechnic Institute and State University, Blacksburg
Ghoshal TB, Sringanengam S, Sengupta CK (1998) Detailed investigation of Chandmari Landslide near Gangtok. Geological Survey of India, Kolkata
Gupta H, Gahalaut VK (2014) Seismotectonics and large earthquake generation in the Himalayan region. Gondwana Res 25(1):204–213
Iverson RM (2000) Landslide triggering by rain infiltration. Water Resour Res 36(7):1897–1910
James N, Sitharam TG (2015) Macro-level assessment of seismically induced landslide hazard for the State of Sikkim, India based on GIS technique. In: IOP Conference series: Earth and Environmental Science 26(1):012027. IOP Publishing
Kanth S R, Iyengar R N (2007) Estimation of seismic spectral acceleration in peninsular India. Journal of Earth System Science. 116(3)
Newmark NM (1965) Effects of earthquakes on dams and embankments. Geotechnique 15(2):139–160
Ramesh MV, Vasudevan N (2012) The deployment of deep-earth sensor probes for landslide detection. Landslides 9(4):457–474
Rawat RK (2005) Geotechnical investigations of Chandmari landslide located on Gangtok-Nathula road, Sikkim Himalaya, India. J Himalayan Geol 26(2):309–322
Reuters (1997) Landslides claim at least 28 in India. CNN. 9 June 1997. http://edition.cnn.com/WORLD/9706/09/india.mudslides/. Last accessed 7 Sept 2016
Roy S, Baruah A, Misra S, Mandal N (2015) Effects of bedrock anisotropy on hillslope failure in the Darjeeling-Sikkim Himalaya: an insight from physical and numerical models. Landslides 12(5):927–941
Sharma AK (2008) Landslide and its mitigation for disaster management using remote sensing and GIS technique-a case study of Gangtok area, East Sikkim. MSc thesis Sikkim Manipal University of Health, Medical and Technological sciences, Gangtok, India
Sharma ML, Douglas J, Bungum H, Kotadia J (2009) Ground-motion prediction equations based on data from the Himalayan and Zagros regions. J Earthquake Eng 13(8):1191–1210
SikkimNow (2011) Around Gangtok, 19 Sept 2011. http://sikkimnow.blogspot.in/2011/09/around-gangtok-19-sept-2011a-four.html. Last accessed 9 Sept 2016
The Sikkim Times (2011) Heavy rains trigger landslides across Gangtok. http://sikkimnews.blogspot.in/2011/06/heavy-rains-trigger-landslides-across.html. Last accessed 14 Sept 2016
Vasudevan N, Ramanathan K (2016) Geological factors contributing to landslides: case studies of a few landslides in different regions of India. In: Institute of Physics Conference Series: Earth and Environmental Science. 30(1):012011-012016. IOP Publishing
Vasudevan N, Kolathayar S, Sridharan A, Ramanathan K (2016) An investigative study of seismic landslide hazards. In: Proceedings of the international conference on recent advances in rock engineering (RARE-2016), 16–18 November 2016, Bengaluru, India, pp 195–204
Acknowledgements
We thank Mr. Ranjith N. Sasidharan for helping us prepare the figures for this paper, Dr. H. M. Iyer, Dr. R. Dhandapani, Dr. Sreevalsa Kolathayar, Dr. P. Thambidurai, Dr. Malay Mukul, Dr. Ganesh Khanal, and Mr. Keshar Kumar Luitel for technical discussions, Mr. Kevin Degnan for help with technical writing and painstakingly proofreading the entire manuscript, and Sri P. P. Shrivastav for his support of this work. We thank the session editor, Dr. Jan Klimeš, for reading our original submission with great care and providing insightful comments. The Amrita University landslide projects, aimed at developing wireless sensor network-based landslide early warning systems, are vast, multi-disciplinary efforts. The team is too large for us to name every member; we gratefully acknowledge their help and support. Above all, we express our heartfelt gratitude for the immense guidance and motivation provided by the Chancellor of our University, Sri Mata Amritanandamayi Devi (Amma). This work was funded by the Ministry of Earth Sciences (MoES), Government of India.
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2017 Springer International Publishing AG
About this paper
Cite this paper
Vasudevan, N., Ramanathan, K., Sridharan, A. (2017). Understanding the Chandmari Landslides . In: Mikoš, M., Vilímek, V., Yin, Y., Sassa, K. (eds) Advancing Culture of Living with Landslides. WLF 2017. Springer, Cham. https://doi.org/10.1007/978-3-319-53483-1_23
Download citation
DOI: https://doi.org/10.1007/978-3-319-53483-1_23
Published:
Publisher Name: Springer, Cham
Print ISBN: 978-3-319-53482-4
Online ISBN: 978-3-319-53483-1
eBook Packages: Earth and Environmental ScienceEarth and Environmental Science (R0)