Beyond Capacity Monitoring: Sentinel-1 Storage Time Series as an Unplanned Auditor of Reservoir Operational Disruptions after the 2023 Yaku Cyclone in Northern Peru

Analysis package for: “Beyond Capacity Monitoring: Sentinel-1 Storage Time Series as an Unplanned Auditor of Reservoir Operational Disruptions after the 2023 Yaku Cyclone in Northern Peru” (manuscript in review). Four reservoirs on the Pacific slope of northern Peru (Poechos, San Lorenzo, Tinajones, Gallito Ciego) are monitored with Sentinel-1 SAR-derived storage time series. Rather than using these series only to estimate storage capacity, this study asks whether their temporal structure alone can reveal operational disruptions of the dam infrastructure. An unsupervised spectral–statistical pipeline (Lomb–Scargle periodogram, bootstrap significance testing, Ward regime clustering, flat-streak detection, Pettitt change-point testing) flags a non-stationary storage regime in Tinajones and Gallito Ciego during 2024–2025. The anomaly is independently confirmed in official daily records from Peru’s National Water Authority (ANA) and, for Tinajones, attributed to unrepaired discharge-canal damage from the March 2023 Yaku cyclone, documented in an official dam-safety report. Poechos and San Lorenzo serve as negative controls. What this repository contains data/sentinel1_series/ — Sentinel-1-derived daily reservoir storage series (2021–2026), one file per reservoir. data/ana_records/ — official daily storage records from Peru’s National Water Authority (ANA), used as independent ground truth. data/gis_basemap/ — third-party GIS layers (SRTM DEM, water-extent masks, country/basin outlines) used only to render the study-area map. data/derived_tables/ — result tables (spectral verification, annual streak summary, seasonal-feature/cluster table). scripts/ — five Python scripts (data analysis, figure generation, methodological flowchart, location map), runnable end-to-end with relative paths. figures/ — all figures as included in the manuscript, plus the methodological flowchart source (.drawio). Relationship to prior work The Sentinel-1 storage time series analysed here are reused, as an input signal only, from a separate study that reconstructed the elevation–area–volume curve of the Poechos reservoir using a deep learning segmentation ensemble, and transferred it zero-shot to the other three reservoirs (manuscript in review; dataset archived at Zenodo, DOI: 10.5281/zenodo.21253273). None of the segmentation, altimetry, or sedimentation results of that study are reused. The present analysis — spectral regime characterization, independent ground-truth anomaly detection, and documentary attribution of an operational disruption — is new. How to cite If you use this repository, please cite both the manuscript and this dataset: Breña Aliaga, J. C., Cruz Machacuay, J., Breña Ore, J. L., & Tacusi Cuadros, D. A. (2026). Beyond Capacity Monitoring: Sentinel-1 Storage Time Series as an Unplanned Auditor of Reservoir Operational Disruptions after the 2023 Yaku Cyclone in Northern Peru. Manuscript submitted for peer review. Breña Aliaga, J. C., Cruz Machacuay, J., Breña Ore, J. L., & Tacusi Cuadros, D. A. (2026). Analysis package for “Beyond Capacity Monitoring: Sentinel-1 Storage Time Series as an Unplanned Auditor of Reservoir Operational Disruptions after the 2023 Yaku Cyclone in Northern Peru” [Data set]. Zenodo. https://doi.org/10.5281/zenodo.21364111 License Creative Commons Attribution 4.0 International (CC BY 4.0). Contact Corresponding author: Juan Carlos Breña Aliaga ([e-mail]), National Water Authority (ANA), Peru.