Scholarlink

<p>Floods are among the most recurrent hydrometeorological hazards in South Asia. The changing monsoon dynamics and reservoir operations influence downstream flooding. This study addresses three key aims: (i) to quantify the spatial extent of inundation during the 2025 flood event in the Sutlej Basin using multi-temporal Sentinel-1 Synthetic Aperture Radar (SAR) data, (ii) to assess land-cover exposure to flooding, and (iii) to evaluate the combined influence of extreme precipitation and reservoir operations on transboundary flood propagation. The flood extent derived from VH-polarised Sentinel-1 images indicated a total inundation of ~ 2693&#xa0;km² (2.3% of the basin area) with accuracy of 0.94 (95%CI: 0.89–0.97). Sentinel-1 + 2 landcover data showed that croplands accounted for more than 70% of the flooded surface, highlighting the vulnerability of agricultural zones in the transboundary plains. Extreme rainfall concentrated over the Bhakra and Pong reservoir catchments caused reservoir expansion of 57% and 91%, exceeding operational limits and triggering emergency releases that coincided with downstream precipitation. These combined effects intensified discharge peaks and flood propagation along the Sutej River (SR). Validation against official and media reports confirmed close agreement with satellite-derived estimates. The findings demonstrate that SAR-based monitoring provides reliable spatial assessment even under cloudy monsoon conditions and can complement existing flood management frameworks. Results showed good accuracy, but limitations due to classification ambiguity in vegetated and built-up areas and limited access to real-time reservoir operation data are still an issue. Integrating real-time satellite observation, rainfall analysis, and reservoir data is essential for early-warning systems, and coordinated response across the border would save structures and livestock damages.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Transboundary flood dynamics in the Sutlej basin (2025): Sentinel-1 SAR insights on inundation and reservoir release impacts

  • 期刊论文

  • 发表日期：

    2026年8月3日

查看全文
  • Aamer Amin,
  • Amir Ali,
  • Saira Batool,
  • Syed Amer Mahmood,
  • Hamid Gulzar

摘要

Floods are among the most recurrent hydrometeorological hazards in South Asia. The changing monsoon dynamics and reservoir operations influence downstream flooding. This study addresses three key aims: (i) to quantify the spatial extent of inundation during the 2025 flood event in the Sutlej Basin using multi-temporal Sentinel-1 Synthetic Aperture Radar (SAR) data, (ii) to assess land-cover exposure to flooding, and (iii) to evaluate the combined influence of extreme precipitation and reservoir operations on transboundary flood propagation. The flood extent derived from VH-polarised Sentinel-1 images indicated a total inundation of ~ 2693 km² (2.3% of the basin area) with accuracy of 0.94 (95%CI: 0.89–0.97). Sentinel-1 + 2 landcover data showed that croplands accounted for more than 70% of the flooded surface, highlighting the vulnerability of agricultural zones in the transboundary plains. Extreme rainfall concentrated over the Bhakra and Pong reservoir catchments caused reservoir expansion of 57% and 91%, exceeding operational limits and triggering emergency releases that coincided with downstream precipitation. These combined effects intensified discharge peaks and flood propagation along the Sutej River (SR). Validation against official and media reports confirmed close agreement with satellite-derived estimates. The findings demonstrate that SAR-based monitoring provides reliable spatial assessment even under cloudy monsoon conditions and can complement existing flood management frameworks. Results showed good accuracy, but limitations due to classification ambiguity in vegetated and built-up areas and limited access to real-time reservoir operation data are still an issue. Integrating real-time satellite observation, rainfall analysis, and reservoir data is essential for early-warning systems, and coordinated response across the border would save structures and livestock damages.