Flood risks in urban areas: More than an act of nature

Flood risks have been escalating in urban and peri-urban areas in Vietnam. However, flood risk management in many of these areas has not received due attention or is not effective. Until now, disaster risk management in Vietnam has mainly focused on rural areas, yet in some cases, flood resilience of urban and peri-urban communities is lower than that of rural areas. Extreme rainfall and flooding events are increasing in frequency, becoming more abnormal and not following the patterns of the past. In the future, this tendency is expected to intensify due to the impacts of climate change. But the increased flood risk and vulnerability in urban areas is not only the result of changes in rainfall and impacts of climate change; it is also a result of many other factors, especially improper urbanization and poor land use and urban development planning. These factors are often beyond the geographical boundaries of individual communities and require interventions that go beyond the capacity of those communities and their authorities. Typical examples include the loss of natural naturepermeable surfaces and water retention areas due to over-concreting; the obstruction of drainage flows and reduction of room for flood water storage due to ground leveling and construction in low-lying areas; and the blocking of floodways by new infrastructure, especially traffic works. These non-climate related causes are not being thoroughly considered and addressed in flood response and urban development planning.