Flash flood is one of the hydro-meteorological hazards that often occurs in Indonesia. Some major factors affecting this hazard are high topography and weak soil structure. Every incident of flash flood has caused losses in the form of damage to infrastructure, victims, and the other losses. Therefore, flash flood hazard areas should be mapped so that community and local government can anticipate the event during heavy rainfall. This study developed a flash flood hazard index using a decision-making model, with approach of the Analytic Hierarchy Process (AHP). With this method, four parameters were calculated, namely the distance to the stream channels, slope, cover and soil types. The weight and rank values were assigned to the layers and classes of each layer respectively. A hazard map was obtained using an algorithm that combines factors in weighted linear combinations. The index of flash flood hazard zone with rainfall factor was analysed with sensitivity analysis shows better result since 13 of 16 flash flood points (81.25%) are in high vulnerability to flooding.

The strategy of design engineering is very important to produce the modernization of technology. The propeller is one of crucial part in the marine design especially for the marine transportation especially for traditional fishing vessel. In this paper, presents a study for analysis of the propeller performance by using numerical simulation in the computational fluid dynamics (CFD). Since the development of CFD simulation, still facing several problems to solve the CFD analysis. The OpenFOAM is open source CFD tool used in this study in order to investigate the propeller performances. OpenFOAM is implemented for open water performances of KCS propeller (KP505). Reynold-averaged Navier Stokes equations (RANS) was applied to estimate the turbulence of K-w SST model. Unstructured mesh in this simulation was employing a hexahedral mesh as mesh generation. The multiple rotating frame (MRF) was produced as method to analysis of propeller performances. The velocity inlet and pressure outlet were put for inflow and outflow boundaries. The wall was set to a far-field boundary. The current study compared to the experimental result for the thrust and torque coefficient to validate the propeller performances. By using MRF technique, the simulation of interaction for the propeller with a relative error less than 2%. Thus, The MRF technique can be used for the practical technique to simulate the ship propeller model especially for the moving multiple zones.