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It is important to explore air pollution and health effects in developing cities for early prevention rather than waiting for conditions to deteriorate as in the current megacities. This study aims to investigate the short-term health effects of air pollution in a large city in the Mekong Delta Region (MDR) of Vietnam. Air pollution data from January 2015 to December 2018 were collected from the Environmental Monitoring Centre of Can Tho City. The data of respiratory and cardiovascular disease (CVD) admissions in 18 hospitals and medical centers were collected. A time-series regression analysis was conducted using distributed lag models to examine the relationship between the air pollutants and hospitalizations including the delayed effect up to 7 days. The research findings reveal that a 10 μg increase in PM10 was associated with an increase of 2.5% in the risk of respiratory admission for all people and 2.2% in the risk of CVD admission for the elderly on the same day. The analysis stratified by age and sex indicates that PM10 resulted in a higher risk of respiratory admission among children (0–5 years old) and males compared with other groups. PM10 and NO2 were significantly associated with CVD admission among the elderly at lag 4 and 6 days. The effects of other air pollutants (SO2, O3) were not observed in this study. As development continues in this region, there is an urgent need for intervention measures to minimize the health impacts associated with the expected increases in air pollution in the MDR. [ABSTRACT FROM AUTHOR]

Despite the widespread implementation of flood control infrastructure, modern cities around the world remain vulnerable to flood hazards. Although flood management has in general placed less emphasis on structural measures, urban flood hazard mitigation continues to fixate on the flood control paradigm, the ideology that flooding must be prevented in the first place, as flooding is assumed to be disastrous. To promote urban flood resilience, this paper argues for the alternative flood adaptation paradigm, which concerns preventing damage when flooding occurs and allows flooding to enter the city. The argument is grounded on our fieldworks on the ecological wisdom of living with floods in the Vietnamese Mekong Delta in two hamlets, Vinh An and Ha Bao, where flooding is mostly harmless and brings benefits. To turn this ecological wisdom of the rural hamlets into practical knowledge, we extract lessons for modern cities: Modern cities need ecological knowledge to nurture ecological wisdom; and need to become agile by developing localized flood-response capacity, striving for timely systemwide adjustment, and turning amphibious. To make these lessons of the ecological wisdom actionable, we translate them into three urban design principles: Urban design should (1) anticipate and accommodate flooding, (2) incorporate the ecological process of flooding, and (3) reveal the flood dynamics to the public. [ABSTRACT FROM AUTHOR]

This study develops a tide propagation model in order to forecast water levels and velocities at a given time and location for the largest city in the Mekong Delta, Can Tho City. The simulation model is applied to a complex waterway system that is characterised by a number of small canals and tributaries, which connect with the main stream. The model, which is verified by comparison with observed water levels during a typical dry season, enables examination of the mechanisms of tidal propagation, which have an impact on floods, inundation and saline water intrusion. The model analysis indicates that the difference in tidal amplitude between a connecting tributary and the main stream is small, whereas the flow velocity largely varies depending on the location. The flow velocity in the tributary, which exceeded 1 m/s, is almost three times that of the main river. This kind of local amplification in flow velocity is important when evaluating flood/inundation risks in urban areas of the Mekong Delta, as small ships are likely to encounter difficulties in handling or risk being overturned due to unexpectedly rapid flows that occur during these abnormal high tides or typhoon storm surges. [ABSTRACT FROM AUTHOR]