ABSTRACT:

Flooding is one of the most destructive natural hazards in tropical mountain basins, yet detailed vulnerability assessments remain scarce where observational data are limited. In this study, we compiled and harmonized high‐resolution geomorphological, hydroclimatic, land‐cover, soil, and population datasets for the 1,777 km² Guatiquía River watershed in the Colombian Andes, covering the period 1991–2022 (DEM at 12.5 m, CHIRPS precipitation at 5.5 km, ERA5 reanalysis at 25 km, MapBiomas land cover at 30 m, and IGAC soil maps) ArticleGuatiquiaRiverWa…. We derived key conditioning factors: slope, Topographic Wetness Index (TWI), Curve Number (CN3), population density, and an Extreme Precipitation Susceptibility Index (EPSI) composed of six ETCCDI climate extremes, and applied a Frequency Ratio (FR) model to quantify their spatial correlation with historical flood occurrences. The resulting vulnerability map highlights the middle‐lower basin, particularly around Villavicencio, as the most susceptible zone, driven by flat terrain, high moisture accumulation, low infiltration (CN3 > 70), and recurrent intense rainfall. Model validation via Receiver Operating Characteristic (ROC) analysis yielded an Area Under the Curve of 0.82, demonstrating robust predictive performance. This work provides the first comprehensive, data‐driven flood vulnerability assessment for the Guatiquía watershed and offers a transferable methodology for other data‐scarce Andean basins. All processed datasets and derived layers are publicly available to support regional water‐resources management and climate‐adaptation planning.