Flood modeling is one of the recognized effective means of assessing the flood risk to people and property. In this study, the concept of flood modeling is applied in Musimusi river at Balingasag, Misamis Oriental. Using the Hydrologic Modeling System… More

Flood modeling is one of the recognized effective means of assessing the flood risk to people and property. In this study, the concept of flood modeling is applied in Musimusi river at Balingasag, Misamis Oriental. Using the Hydrologic Modeling System (HMS) and River Analysis System (RAS) of the Hydrologic Engineering Center (HEC), hydrologic and hydraulic models were developed to conduct simulations on the rainfall-runoff and flood inundation processes. Data from the Typhoon Seniang event was used as main input for the calibration of basin model and consequently validated using quantitative statistics. Further simulations on specific return periods using historical data from PAG-ASA were conducted using the calibrated model. River flow hydraulics was performed through unsteady flow analysis reconstructing the Typhoon Seniang event and constructing the 5-year, 25-year and 100-year return period scenarios, spatially illustrating flood inundations on the floodplain of Musimusi. Results of this research revealed successful simulation of flood scenarios indicating applicability of both developed HEC-HMS and HEC-RAS models. Moreover, with the integration of high resolution Digital Elevation Model (DEM), modeling is significant towards consequent development of highly precise and detailed flood hazard maps helpful especially to local governing units for the total improvement of disaster risk reduction strategies. Less

Flooding is one of the most devastating natural disasters in the Philippines, especially in Mindanao. This study aimed to generate datasets of flooding along the Gingoog River based on Geographic Information System (GIS). The method employed simulation and mapping of… More

Flooding is one of the most devastating natural disasters in the Philippines, especially in Mindanao. This study aimed to generate datasets of flooding along the Gingoog River based on Geographic Information System (GIS). The method employed simulation and mapping of flood hazards using the Hydrologic Engineering Center’s Hydrologic Modeling System (HEC-HMS) and the HEC-River Analysis System (HEC-RAS) within the GIS environment. Rainfall data on December 15, 2015, with a total amount of 20.8 mm and peak discharge of 43.49 m3s-1, were used to simulate flood hazards. The model was calibrated, and its accuracy was tested, and after which, its overall evaluation showed a satisfactory performance, implying applicability to simulate floods during extreme rainfall events. Using Light Detection and Ranging (LiDAR) data, flood maps of the three return periods were generated within HEC-RAS. Results showed that flooding extended up to 2.965 km2, 4.165 km2, and 5.040 km2 with maximum flood depths of 7.77 m, 8.12 m, and 8.49 m for 5-year, 25-year, and 100-year return periods, respectively. The model, together with the hydrologic behavior of the watershed such as the extent of flooding, is very helpful for the development and enhancement of early warning systems in the affected areas. Less