Thesis (B.S.) -- Cagayan State University, 2025.

Rivers are becoming more unpredictable due to climate change. Cagayan has experienced extensive flooding during monsoon season which brought drastic impacts on the communities, threatening public health, weakening economies, and decreasing the quality life in many places. The study analyze the riverbank stability aligning with the Department of Public Works and Highways (DPWH) guidelines. The methodology integrates hazard vulnerability assessments (seismic and hydro-meteorological), geotechnical investigations, and slope stability modeling using Rocscience Slide 2 software. Results were identified considering both original and maximum expected water level having a Factor of Safety equal to 0.997 and 0.996 for Bishop Simplified Method and Janbu Method respectively, which is considered unstable. On the other hand, the Factor of Safety for maximum expected water level is 1.036 and 1.035 for Bishop Simplified Method and Janbu Method respectively, and identified as quasi stable which means it has a low stability. Countermeasures against river erosion were selected based on the guidelines of the JICA and DPWH standards. The selected countermeasure against riverbank failure was based on these site-specific conditions and constraints of the area concluding that gabion walls were found to be the most appropriate slope protection option and represented a cost- conscious, could withstand dynamic hydraulic condition, ecofriendly method of stabilizing slopes and extending embankment construction lifetimes making a versatile solution in the study area.