Massart et al. (2026) Filling the Gap: Elevation-Based Sentinel-1 Surface Soil Moisture Retrieval over the Austrian Alps

⚠️ Warning: This summary was generated from the abstract only, as the full text was not available.

Identification

• Journal: Remote Sensing
• Year: 2026
• Date: 2026-03-10
• Authors: Samuel Massart, Mariëtte Vreugdenhil, Juraj Parajka, Carina Villegas-Lituma, Ignacio Borlaf-Mena, Patrik Sleziak, Wolfgang Wagner
• DOI: 10.3390/rs18060855

Research Groups

Not explicitly stated in the provided text.

Short Summary

This study introduces a novel approach to retrieve surface soil moisture (SSM) across the complex topography of the Austrian Alps by aggregating Sentinel-1 backscatter into 100 m elevation bands. The resulting product provides consistent and elevation-stratified SSM information across over 80% of the region, demonstrating satisfactory agreement with ERA5-Land and capturing precipitation-driven anomalies.

Objective

• To develop and evaluate a novel retrieval approach for surface soil moisture (SSM) using Sentinel-1 data, specifically designed to overcome the limitations of existing operational products in capturing SSM spatial variability across the steep and complex terrain of the Austrian Alps.

Study Configuration

• Spatial Scale: Austrian Alps, with data aggregated into 100 m elevation bands per sub-basin and aspect, covering more than 80% of the region.
• Temporal Scale: 2016 to 2024.

Methodology and Data

• Models used: Orbit-wise change detection algorithm for surface soil moisture retrieval.
• Data sources:
  • Sentinel-1 radiometric terrain-corrected backscatter (γ0).
  • ERA5-Land (for evaluation).
  • 264 precipitation stations from Geosphere (for comparison).

Main Results

• The novel retrieval approach generated over 34,000 surface soil moisture timeseries for the Austrian Alps.
• Satisfactory agreement was observed with ERA5-Land (Pearson correlation > 0.46 below 400 m).
• The product effectively captured in situ precipitation-driven anomalies, showing the strongest performance below 400 m (Spearman correlation > 0.47), particularly over grasslands and south-facing slopes.
• Sentinel-1 provides consistent and elevation-stratified information across more than 80% of the Austrian Alps, a region typically excluded from operational products.
• Limitations were noted at high elevations and over dense vegetation.

Contributions

• Presents a novel and robust retrieval approach for surface soil moisture specifically tailored for complex Alpine topography, addressing the limitations of existing operational products that often mask steep terrain or lack sufficient spatial resolution.
• Provides a unique, consistent, and elevation-stratified surface soil moisture product for over 80% of the Austrian Alps, a region critical for water resources but challenging for remote sensing.
• Highlights the significant potential of Sentinel-1 data to support hydrological modeling, drought monitoring, and water resource management in mountainous regions.

Funding

Not explicitly stated in the provided text.

Citation

@article{Massart2026Filling,
  author = {Massart, Samuel and Vreugdenhil, Mariëtte and Parajka, Juraj and Villegas-Lituma, Carina and Borlaf-Mena, Ignacio and Sleziak, Patrik and Wagner, Wolfgang},
  title = {Filling the Gap: Elevation-Based Sentinel-1 Surface Soil Moisture Retrieval over the Austrian Alps},
  journal = {Remote Sensing},
  year = {2026},
  doi = {10.3390/rs18060855},
  url = {https://doi.org/10.3390/rs18060855}
}