EDUCATIONE: Journal of Education Research and Review
Volume 4, Issue 2, July 2026

INTEGRATED HYDROLOGICAL-HYDRAULIC MODELING FOR FLASH-FLOOD INUNDATION EXPOSURE ASSESSMENT

Ficky Marcellino Oroh (Universitas Sam Ratulangi)
Cindy Jeane Supit (Universitas Sam Ratulangi)
Tommy Miran (Kementerian Pekerjaan Umum)



Article Info

Publish Date
31 Jul 2026

Abstract

Flash floods in small tropical catchments require spatially explicit analysis, yet data scarcity often limits model verification. This study integrates HEC-HMS rainfall-runoff modeling and HEC-RAS two-dimensional hydraulic simulation to reconstruct the 19 February 2017 flood in the Nuay River watershed and to assess village-scale inundation exposure. Annual-maximum daily rainfall records for 2014-2024 were compiled from the Ranowangko Tara-Tara and Tondano-Paleloan stations. Missing Tondano-Paleloan observations in 2015, 2021, and 2024 were not treated as zero; Thiessen weights were renormalized to the available station for those years. The corrected annual-maximum series was analyzed with the Log Pearson Type III distribution, giving design rainfall from 111.39 mm for the 2-year return period to 283.57 mm for the 1,000-year return period. The reconstructed 2017 HEC-HMS event produced a peak discharge of 20.0 m3/s at 03:00. HEC-RAS 2D outputs show inundation concentrated near the river corridor and low-lying terrain, with displayed depth classes extending from less than 1 m to 5 m. Talikuran Satu and Tounelet Satu had the largest inundated-area proportions, 3.2% and 2.1%, respectively. These classes are interpreted as inundation exposure rather than comprehensive flood risk because population, assets, vulnerability, and velocity were not included. The integrated workflow supports screening-level mitigation prioritization, while uncertainty remains due to the short rainfall record, event-based non-gauged calibration evidence, and incomplete hydraulic-project metadata.

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Journal Info

Abbrev

educatione

Publisher

Subject

Education Social Sciences

Description

EDUCATIONE: Journal of Education Research and Review publishes critical, integrative reviews of research literature bearing on education. Such reviews should include conceptualizations, interpretations, and syntheses of literature and scholarly work in a field broadly relevant to education and ...