DEVELOPMENT OF FLOOD FORECASTING MODEL AND WARNING SYSTEMS AT RIVER OF WAY RUHU - AMBON

Way Ruhu river has a main river length of 11.8 km with a watershed of 17.2 km2 , and the slope of the land is steep. People in the Way Ruhu river watershed are often threatened by flash. Therefore, this study was conducted with the aim to determine the magnitude and time of flooding in the Way Ruhu river watershed, the modeling results will applied in android, so that people can evacuate early because information can be received more quickly and the Government can prepare better mitigation programs. Modeling methods are carried out using 2D software HEC-RAS 5.0.7 which requires hydrological and topographical data as the main inputs. Output from HECRAS is flood map, flood height, and duration of flood. The results of this study indicate that the time between upstream river rise and the arrival of floodwater in the downstream is less than one hour, with flood characteristics as high as 1-5 meters and receding within 4 to 11 hours