Skip to main content
Log in

Lithological and tectonic response on catchment characteristics of Rishi Khola, Sikkim, India

  • Original Article
  • Published:
Journal of Mountain Science Aims and scope Submit manuscript

Abstract

Rishi Khola, a sub-watershed of Teesta river, traverses along the Main Central Thrust (MCT) with a multitude of litho units and structural entities. This study examines the impact of tectonic and lithologic controls in configuring the catchment characteristics of Rishi Khola, Sikkim, India. Corrected SRTM 30 m DEM and Landsat 8 satellite image have been used for extracting the river network, preparing the sub-catchments, the longitudinal profile and thereby calculating the morphotectonic indices. An aggregated tectonic index (ATI) has been prepared to map the intensity of tectonic perturbations in the fluvial environment using the entropy weightage method (EWM) and Weighted Linear Combination (WLC). The undulating nature of the longitudinal profile with prominent knick points confirms the presence of tectonic disturbances and lithological variations. From all the computed morphotectonic indices and the ATI, it has been evident that the region has experienced surface deformations. When viewed at the entire catchment, the morphotectonic indices suggest ample responses to the tectonic perturbations due to the dominance of lithology-controlled hill slope processes and fluvial erosion. The spatiality of the tectonic sensitiveness is rather concentrated into certain pockets of differential stress field formed due to fault thrusting of the Himalayas. The study chiefly focuses on the peculiarity of the watershed which displays a complex response of tectonic and rock structure; wherein the proposed methodology has been successful in excavating such complex responses around the Himalayan thrusts.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

Download references

Acknowledgement

The authors thank Soumik Roy, Debolina Mitra and Chandradeep Mukherjee, post graduate students of Department of Geography, Vidyasagar College for their assistance in capturing field photographs. We also thank the assistance received from the Department of Geography, Vidyasagar College, Kolkata. We profusely thank Dr. Partha Basu, Former Professor, Department of Geography, Bhairab Ganguly College, Kolkata for his valuable insight during the fieldwork.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Sohini Neogy.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Saha, U.D., Neogy, S., Kar, J. et al. Lithological and tectonic response on catchment characteristics of Rishi Khola, Sikkim, India. J. Mt. Sci. 18, 3003–3024 (2021). https://doi.org/10.1007/s11629-021-6666-x

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11629-021-6666-x

Keywords

Navigation