Mesallam et al. (2026) Strategic dam site selection and hazard mapping using remote sensing: insights from Wadi Araba, Egypt

Identification

• Journal: Scientific Reports
• Year: 2026
• Date: 2026-03-19
• Authors: Mona A. Mesallam, Zenhom E. Salem, A. M.M. Al Temamy, Tamer Abu-Alam, Amr S. Fahil
• DOI: 10.1038/s41598-026-39883-9

Research Groups

• Geology Department, Faculty of Science, Tanta University, Tanta, Egypt
• Geophysical Exploration Department, Desert Research Center, El Matariya, Egypt
• Department of Arctic Marine Biology, UiT The Arctic University of Norway, Tromsø, Norway
• Outermost Regions Sustainable Ecosystem for Entrepreneurship and Innovation (OSEAN), University of Madeira, Funchal, Portugal

Short Summary

This study developed an integrated remote sensing, GIS, and Analytical Hierarchy Process (AHP) framework to map flash flood susceptibility and identify optimal dam sites for flood mitigation and groundwater recharge in Wadi Araba, Egypt. The framework successfully delineated flood-prone areas and prioritized dam locations, demonstrating its utility for water resource management in hyper-arid regions.

Objective

• To develop and apply an integrated remote sensing (RS), Geographic Information Systems (GIS), and Analytical Hierarchy Process (AHP) framework for flash flood susceptibility mapping and optimal dam site selection in Wadi Araba, Egypt.
• To identify flash-flood-prone areas and determine strategic dam locations for flood mitigation and groundwater recharge.

Study Configuration

• Spatial Scale: Wadi Araba basin, Egypt, covering approximately 2,800 square kilometers, located along the western margin of the Gulf of Suez between the Northern and Southern Galala Plateaus.
• Temporal Scale: Rainfall data aggregated annually from 2011 to 2021. Land Use/Land Cover (LULC) data from 2023.

Methodology and Data

• Models used:
  • Geospatial decision-support framework.
  • Remote Sensing (RS) and Geographic Information Systems (GIS) for data processing and mapping.
  • Multi-criteria decision analysis (MCDA) using the Analytical Hierarchy Process (AHP) for weighting and overlay.
  • Weighted overlay model for susceptibility and suitability mapping.
  • Receiver Operating Characteristic (ROC) analysis and Area Under the Curve (AUC) metrics for model validation.
• Data sources:
  • Satellite imagery: SRTM 30 meter Digital Elevation Model (DEM) (USGS Earth Explorer), Sentinel-2-derived 10 meter Land Use/Land Cover (LULC) (Esri Living Atlas).
  • Satellite precipitation product: University of East Anglia Climatic Research Unit gridded Time Series (CRU TS Version 4.06), monthly precipitation at 0.5° × 0.5° spatial resolution (2011–2021).
  • Ancillary datasets: Paved-road vectors (OpenStreetMap via BBBike extracts), regional lithology, soil texture (FAO).
  • Derived layers: Slope, elevation, hillshade, lineaments, drainage density (kilometers per square kilometer), distance to main streams, distance to roads, and Topographic Wetness Index (TWI).

Main Results

• Flash Flood Susceptibility: The final map classified Wadi Araba into high-risk (0.53 square kilometers), moderate-risk (2354.8 square kilometers), and low-risk (1671.34 square kilometers) zones. The highest risk areas were concentrated in the southern Galala Plateau, moderate-risk zones occurred in lowland and downstream basins, and low-risk zones were mainly located in the northern Galala Plateau and western Wadi Araba.
• Dam Site Suitability: High suitability zones for dam construction occupied only approximately 0.12% of the study area, primarily in the central Wadi where higher-order drainage converges, rainfall is relatively higher, distances to roads are shorter, and lineament density is lower. Among three proposed sites, Dam 1 was identified as the most suitable due to its superior storage geometry (lake volume ~31.6 million cubic meters), shorter crest length (688 meters), and more uniform side sector, compared to Dam 2 (~3.49 million cubic meters) and Dam 3 (~0.758 million cubic meters).
• Validation: The flash flood susceptibility model showed a medium AUC value of approximately 0.6–0.7 (specifically 0.690), while the dam site suitability model demonstrated a good AUC value of approximately 0.7–0.8 (specifically 0.742). The AHP consistency ratio (CR) was maintained at ≤ 0.1 for both analyses (CR = 0.09 for flood susceptibility and CR = 0.0736 for dam suitability).

Contributions

• Developed a reproducible and operational RS–GIS–AHP framework for flash flood susceptibility zonation and dam site prioritization in hyper-arid, data-scarce regions, providing a decision-ready tool for water resource management.
• Provided critical insights for protecting infrastructure, reducing flood risk, and securing freshwater resources through managed aquifer recharge in Wadi Araba, Egypt.
• Contributed to advancing reproducible methods for flood-hazard assessment in hyper-arid settings, supporting Sustainable Development Goals (SDG 6: Clean Water and Sanitation, SDG 9: Industry, Innovation, and Infrastructure, SDG 13: Climate Action).
• Distinguished the functional role of lineament density for water storage (lower density preferred for dam tightness) versus groundwater recharge (higher density suitable for enhancing focused recharge).
• Offered a practical framework for integrated water management, hazard mitigation, and sustainable development planning in the study area and similar hyper-arid environments.

Funding

• Science, Technology & Innovation Funding Authority (STDF) under grant number 48506.

Citation

@article{Mesallam2026Strategic,
  author = {Mesallam, Mona A. and Salem, Zenhom E. and Temamy, A. M.M. Al and Abu-Alam, Tamer and Fahil, Amr S.},
  title = {Strategic dam site selection and hazard mapping using remote sensing: insights from Wadi Araba, Egypt},
  journal = {Scientific Reports},
  year = {2026},
  doi = {10.1038/s41598-026-39883-9},
  url = {https://doi.org/10.1038/s41598-026-39883-9}
}