Flood inundation analysis using a distributed tank model for a flat, low-lying agricultural area undergoing urbanization in Hanoi, Vietnam. (Special Issue: Sustainable water and land management in tidal areas.)

摘要

In the 2000 s, urbanization has extended to approximately 30% of the total upstream area of the Song Nhue Hydraulic Structure Scheme (HSS) in Hanoi, Vietnam, and the Song Nhue HSS area is predicted to become completely urbanized by 2030. In this study, flood inundation analyses were carried out for the upstream area of the Song Nhue HSS. The analyses were conducted using a horizontally distributed continuous tank model. First, the distributed tank model was constructed on the basis of the hydraulic dimensions of rivers, irrigation and drainage canals, gates, and pumping stations, as well as information about land use and the drainage network. Then, six observed flood events with return periods of 2, 3, 5, 10, 30, and 100 years were selected from past records and simulated using the model. The comparison between the simulated and the observed upstream water levels in the outlets indicated that the developed model could accurately estimate variations in water levels. Second, a scenario analysis based on predictions of urban growth was conducted using the distributed tank model. The scenario analysis suggests necessary and effective measures that can be taken to prevent flood inundation in the targeted area.