Shahab et al. (2025) Spatiotemporal Evolution of Water Bodies in the Tarbela Dam Region: Drought Impact and Propagation Mechanisms Using Google Earth Engine

Identification

• Journal: Water Resources
• Year: 2025
• Date: 2025-11-20
• Authors: Muhammad Shahab, Fahad Alshehri, Liaqat Ali, Seema Anjum Khattak
• DOI: 10.1134/s0097807825700320

Research Groups

• Abdullah Alrushaid Chair for Earth Science Remote Sensing Research, Geology and Geophysics Department, King Saud University, Riyadh, Saudi Arabia
• National Centre of Excellence in Geology, University of Peshawar, Peshawar, Pakistan

Short Summary

This study investigated the spatiotemporal dynamics of water bodies in the Tarbela Dam region using remote sensing and Google Earth Engine, revealing significant losses of permanent water bodies, emergence of new seasonal features, and transitions between water body types, primarily driven by climate change, sedimentation, and anthropogenic factors.

Objective

• To examine the spatiotemporal dynamics of water bodies in the Tarbela Dam region, leveraging transition mapping and pixel-level analysis to identify key hydrological changes and their potential drivers.

Study Configuration

• Spatial Scale: Tarbela Dam region, located on the Indus River in Haripur District, Khyber Pakhtunkhwa province, Pakistan.
• Temporal Scale: 1984 to 2022.

Methodology and Data

• Models used: Google Earth Engine (GEE) for large-scale geospatial analysis, threshold-based classification, and change detection techniques.
• Data sources: European Commission’s Joint Research Centre (JRC) Global Surface Water (GSW) product, derived from Landsat imagery, with a spatial resolution of 30 meters. Key GSW layers utilized include Permanent Water Layer, Seasonality Layer, Recurrence Layer, and Transition Layer.

Main Results

• Water bodies were classified into nine distinct transition classes, including permanent, seasonal, ephemeral, and their transformations (e.g., new seasonal, lost permanent, seasonal to permanent).
• Significant losses of permanent water bodies were observed, alongside the emergence of new seasonal and permanent features, and transitions from seasonal to stable regimes.
• Pixel-based analysis showed high recurrence (100%) and stability in permanent water bodies.
• Areas categorized as "lost permanent" or "lost seasonal" exhibited marked reductions in occurrence and seasonality, with a decrease in occurrence of -83% for lost permanent water bodies.
• The observed changes are attributed to a combination of climate change (e.g., extreme rainfall events), sedimentation, and anthropogenic factors such as upstream water management, water extraction, and land-use changes.
• The formation of new permanent water bodies showed moderate recurrence rates (50%), suggesting a gradual transition towards stability influenced by upstream water management and groundwater recharge.

Contributions

• Provides a detailed spatiotemporal assessment of water body dynamics in the critical Tarbela Dam region, a key hydrological area in the Indus River basin.
• Offers valuable insights into the complex interplay of climatic variability and anthropogenic activities driving hydrological transformations.
• Highlights the utility of JRC Global Surface Water data within Google Earth Engine as a standardized tool for monitoring water resources globally.
• Underscores the urgent need for integrated watershed management strategies, climate-resilient planning, and sustainable interventions (e.g., afforestation, optimized irrigation, rainwater harvesting) to mitigate water loss and enhance resilience to climate change impacts.

Funding

• Abdullah Alrushaid Chair for Earth Science Remote Sensing Research at King Saud University.
• Ongoing institutional funding.

Citation

@article{Shahab2025Spatiotemporal,
  author = {Shahab, Muhammad and Alshehri, Fahad and Ali, Liaqat and Khattak, Seema Anjum},
  title = {Spatiotemporal Evolution of Water Bodies in the Tarbela Dam Region: Drought Impact and Propagation Mechanisms Using Google Earth Engine},
  journal = {Water Resources},
  year = {2025},
  doi = {10.1134/s0097807825700320},
  url = {https://doi.org/10.1134/s0097807825700320}
}