Abstract—Rainfall-induced landslides pose a significant
threat to tropical mountain roads, where the interaction of
hydrological loading, geomorphic development, and soil
weakening drives failure. This study presents an integrated
hydro-geomorphic diagnosis of the July 2022 Callawa–Fatima
landslide in Davao City, Philippines, by combining field surveys,
drone photogrammetry, historical satellite imagery, Digital
Elevation Models (DEMs), rainfall records, and numerical slope
stability modeling. Multi-temporal analysis revealed a tensile
crack along the ridge crest as early as 2015, while 5-m contour
interpretation highlighted topographic irregularities that
signaled long-term geomorphic preconditioning. Hydrological
assessment based on rainfall data revealed that several days of
antecedent wetting, from July 8 to 12, 2022, saturated the slope
before the short-duration, high-intensity rainfall on July 13-14,
2022, triggered the failure. Catchment modeling in Quantum
Geographic Information System (QGIS): Geographic
Resources Analysis Support System (GRASS) module
confirmed concentrated flow paths converging toward the
failure zone. Limit-equilibrium simulations conducted in GEO5
demonstrated that the slope was already marginally unstable
under dry-season conditions with Factor of Safety,
FoS≈0.87–1.35, and transitioned to global instability under
rainfall-induced pore-pressure loading with FoS ≈ 0.58–0.76.
During the spatial exposure, QGIS deep-learning mapping,
identified house location along the active scarps as directly
exposed and downstream community as indirectly at risk. The
integrated framework offers a cost-effective and transferable
approach for diagnosing rainfall-induced slope failures and
enhancing community resilience in tropical mountain regions.
Keywords—hydro-geomorphic diagnosis, catchment
hydrology, slope stability, tropical mountain roads, community
resilience
Cite: Lester G. Padilla and Eleonor V. Palconit, "Hydro-Geomorphic Diagnosis of a Rainfall-Induced Landslide in Davao City, Philippines: Implications for Community Resilience," International Journal of Environmental Science and Development vol. 17, no. 2, pp. 164-175, 2026.
Copyright © 2026 by the authors. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).