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Natural disasters are common worldwide, especially in tropical countries. Floods are one such frequent disaster that occur in the tropical country of Indonesia. Floods cause disasters in many vulnerable societies living in the area. Therefore, it is necessary to conduct risk assessments for flood mitigation. The objective of this research is to support decision-making for flood risk assessment by selecting priority sub-systems. The research was conducted in Surabaya, East Java, and Indonesia. The Surabaya drainage system is divided into five districts consisting of several sub-systems facing inundation problems. This causes challenges for the government in selecting which sub-systems should be prioritized to overcome these problems. Consequently, a rank priority for sub-systems is required. This research validated whether the Analytics Hierarchy Process (AHP) method was applicable and appropriate to weight priority factors to select the priority drainage system. It weighs historical flood data by considering several criteria related to floods, consisting of flood hazards, social economics, and the environment. Flood hazard is defined as the severity level of flooding indicated by three indicators: inundation area, inundation depth, and inundation duration. Social-economics is a criterion covering population density and land use types consisting of residential areas, commercial and services areas, public facilities, industrial areas, port areas, and mix used development support areas. Environment is a criteria indicated by green open space, flood-prone areas, watershed catchment areas, and storage areas. The weighting result convinced the decision makers as to the related parameters which should be considered in order to support appropriate and effective flood mitigation. Further, due to budget constraints, the results of the research can be used to assist the municipal government in selecting which drainage system should be prioritized for management. The AHP result reveals that the priority drainage systems are Wonorejo sub system (Jambangan district), Greges sub system (Genteng district), Kedurus sub system (Wiyung district), Kalibokor sub system (Gubeng district), and Tambak Dono sub system (Tandes district). The result was confirmed to several respondents from Department of Public Works, Highways, and Drainage Management involved with the drainage system in Surabaya. It is indicates that the AHP results mostly are applicable to the existing condition. [ABSTRACT FROM AUTHOR]

Continually changing shipping industry practices, cargo composition, world markets, and competition among ports are making revenue estimates uncertain. This paper demonstrates the application of Monte Carlo simulation for scrutinizing sources of uncertainty and their impact on investment risk. Strengths and weaknesses of Monte Carlo simulation are discussed using the Port of Colombo development project in Sri Lanka as a case example.

This paper presents a flood inundation analysis to determine the possibility of flooding in urban areas. Many studies have conducted flood simulations to generate inundation problems due to river overflow. Urban flood problems commonly occur because of rainfall in subcatchments that do not enter the channel effectively. Therefore, it is necessary to analyze the inundation that occurs owing to overland flow. This study investigates the usefulness of rain-on-grid boundary conditions compared to flow hydrographs to represent the overland flow. The 2D shallow water equation was applied using the HEC RAS 2D model to select suitable boundary conditions to describe watershed problems. The rain-on-grid boundary condition gives a direct rainfall-runoff calculation in the simulation. The flow hydrograph was calculated separately using the rainfallrunoff analysis based on the storm-water-management model. Although rain-on-grid represents the real physical condition, it is difficult for the 2D hydrodynamic model to assess the drainage channel. However, the flow hydrograph boundary condition shows good results compared qualitatively with historical data based on on-site observations obtained from the Department of Public Works, Highways, and Drainage Management. Furthermore, this research provides the capability of flow hydrographs and rain-on-grid boundary conditions for flood simulation in urban areas. The results can be used to conduct an appropriate future simulation of urban drainage planning. [ABSTRACT FROM AUTHOR]