Research

🔬 Overview

My research centers on understanding the evolution of glacial lakes and associated hazards, particularly Glacial Lake Outburst Floods (GLOFs), in the Sikkim Himalaya. I use remote sensing, GIS, and field-based approaches to monitor lake dynamics and assess climate-induced changes in fragile mountain ecosystems.

Key Themes

1. Glacial Lake Evolution

• Mapping and monitoring glacial lakes using multi-temporal satellite imagery
• Analyzing spatial expansion trends and climate sensitivity
• Bathymetric and geophysical profiling of glacial lakes

2. GLOF Hazard Assessment

• Risk zonation using Multi-Criteria Decision Analysis (MCDA)
• Identification of high-risk lakes using morphometric and hydrological indicators
• GLOF modeling and impact forecasting

3. Remote Sensing and Geospatial Tools

• Image classification using Sentinel, Landsat, and PlanetScope data
• Analysis with Google Earth Engine (GEE), QGIS, and ArcGIS
• Integration of UAV/drone data with satellite observations

4. Field Research

• Expeditions to high-altitude glacial lake regions in Sikkim and Ladakh
• On-site measurements of lake depth, sediment cores, and geomorphic features
• Collaborations with local authorities for community risk awareness

Ongoing Projects

• Sikkim Glacier Hazard Commission (2025–present)
  Supporting hazard assessment and public communication strategies for glacial risks.

• DST Centre of Excellence Project (2023–present)
  Investigating climate-driven lake formation and developing risk mitigation approaches in high-mountain Asia.

Selected Publications

• Rajak, R. et al. (2024). Dynamics of Vulnerable Glacial Lakes in the Sikkim Himalayas. Journal of Climate Change
• Rajak, R. et al. (2022). GLOF Risk using MCDA in Changme Khangpu Basin. (In Review)
• Sattar, A. et al. (2025). The Sikkim Flood of October 2023. Science

Collaborations

• Association of Polar Early Career Scientists (APECS)
• Sikkim University, DST India
• International Cryosphere Climate Programs (IGCP/UNESCO)

Tools & Skills

• GIS/RS: QGIS, ArcGIS, SNAP, Google Earth Engine
• Programming: Python for image analysis and geospatial modeling
• Fieldwork: Glacier monitoring, bathymetry, geophysical surveys