Besnier et al. (2026) Crossing the Threshold: Land Cover Change Triggers Hydrological Regime Shift in Brazil’s Itaipu Hydropower Region

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Identification

• Journal: Remote Sensing
• Year: 2026
• Date: 2026-03-10
• Authors: Jessica Besnier, Augusto Getirana, V. Lakshmi
• DOI: 10.3390/rs18060848

Research Groups

Not explicitly mentioned in the provided text.

Short Summary

This study investigates hydrological transitions and their statistical associations with land cover changes in the Itaipu study region from 2002 to 2023. It identifies a significant basin-wide shift in Terrestrial Water Storage Anomalies (TWSAs) in mid-2009, strongly coupled with agricultural expansion and land cover changes, leading to increased runoff generation.

Objective

• To investigate hydrological transitions and their statistical associations with land cover changes in the Itaipu study region from 2002 to 2023.

Study Configuration

• Spatial Scale: Upper Paraná River Basin (UPRB), Itaipu study region (basin-wide).
• Temporal Scale: 2002 to 2023.

Methodology and Data

• Models used: Pettitt’s breakpoint test, Mann–Kendall trend analysis, Principal Component Analysis, Granger causality analysis, Water balance decomposition.
• Data sources: GRACE/GRACE-FO (Gravity Recovery and Climate Experiment Follow-On) Terrestrial Water Storage Anomalies (TWSAs), MODIS (Moderate Resolution Imaging Spectroradiometer) land cover, CHIRPS (Climate Hazards Group InfraRed Precipitation with Station data) precipitation, LandScan population density.

Main Results

• A significant basin-wide shift in Terrestrial Water Storage Anomalies (TWSAs) was detected in mid-2009.
• Post-2009, storage increased by 151.6 cm at Itaipu and 103.1 cm at Yguazú Reservoir.
• Cropland expanded from 13.5% to 37.9% of total land cover, while savanna declined from 28.1% to 24.2% over the study period.
• After 2009, correlations between land cover and TWSAs strengthened substantially: wetlands (r = 0.88), croplands (r = 0.73), and savannas (r = −0.81; all p < 0.001).
• Land use change explains 39–41% of TWSA variance, exceeding hydroclimatic contributions.
• Granger causality analysis revealed bidirectional coupling between wetlands and water storage at Itaipu, and predictive influence of cropland and savanna dynamics on downstream hydrology in the Yguazú basin.
• Water balance decomposition indicated a post-2009 regime shift, with residual storage transitioning from −10.6 cm to +4.7 cm and 78% greater runoff generation per unit precipitation, consistent with reduced infiltration capacity.

Contributions

• Provides a comprehensive characterization of regional hydrological responses to land cover change and climate variability at management-relevant scales in the Upper Paraná River Basin.
• Quantifies the strong coupling between landscape transformation, particularly agricultural expansion, and basin-scale water storage variability.
• Demonstrates that land use change is a dominant driver of Terrestrial Water Storage Anomalies, explaining a greater proportion of variance than hydroclimatic factors.
• Identifies a significant post-2009 hydrological regime shift marked by increased runoff generation and reduced infiltration capacity, directly linked to land cover changes.
• Highlights the intensifying land–water feedback and the critical need for adaptive watershed management strategies in regions facing rapid agricultural expansion and climate variability.

Funding

Not explicitly mentioned in the provided text.

Citation

@article{Besnier2026Crossing,
  author = {Besnier, Jessica and Getirana, Augusto and Lakshmi, V.},
  title = {Crossing the Threshold: Land Cover Change Triggers Hydrological Regime Shift in Brazil’s Itaipu Hydropower Region},
  journal = {Remote Sensing},
  year = {2026},
  doi = {10.3390/rs18060848},
  url = {https://doi.org/10.3390/rs18060848}
}