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Alternative Energy: Hydropower
Published in Brian D. Fath, Sven E. Jørgensen, Megan Cole, Managing Air Quality and Energy Systems, 2020
Andrea Micangeli, Sara Evangelisti, Danilo Sbordone
A removable type of floodgates is flashbooks gates—wooden panels usually installed on the cap of the barrier that allow the increase of the water surface and that can be removed during floods, avoiding the inundation of the upstream fields.[8]
Categories and types of flood adaptation measures applicable in the design of public spaces
Published in Maria Matos Silva, Public Spaces for Water, 2019
The case of Main’s riverside in Miltenberg, Germany, is a good example of a sculpted floodwall integrated in the design of a public space. With changing slopes and a base of varied thickness, the wall enriches the surrounding public space as an individual sculptural element. Besides encompassing a car park, green open spaces and pedestrian and bicycle paths, the public space adjoining to this sculpted floodwall is also used as an event area, namely for the Michaelismesse fair. At night, its design is exacerbated by means of illumination. During extreme flooding, the height of the wall can be further increased with additional automatic floodgates, thus also protecting the area to the one-in-100-year flood events (Prominski et al., 2012).
Public perception of typhoon signals and response in Macau: did disaster response improve between the 2017 Hato and 2018 Mangkhut typhoons?
Published in Georisk: Assessment and Management of Risk for Engineered Systems and Geohazards, 2021
Hiroshi Takagi, Xiong Yi, Jinghui Fan
The Macau SAR Government announced a plan for protecting the Inner Harbor Area – one of the areas most impacted – from storm surge. This plan involves a 650-m long huge movable floodgate system at the mouth of the Wan Chai waterway (Moura 2018). Figure 2-Q8 demonstrates that many respondents hope that the river mouth floodgate will be constructed and the existing dikes are improved. During our survey, however, no construction of the floodgate or improvement of the dikes was apparent. Although the existing dike was not capable of holding back the storm surge, Figure 1(a) shows that it has yet to be raised. Given that no such construction or improvements have been implemented, it is interesting that the citizens’ impressions of the government’s disaster response improved significantly. During our second survey, we found indications of possible storm-surge height on traffic poles on several streets in downtown Macau (e.g. Figure 1(e,f)), which did not exist during our first survey immediately after Hato – meaning that risk of storm surge may have been more recognised after Hato. Thus, it seems that although the government has not invested in hard countermeasures for typhoon preparation, the soft investments may have greatly contributed to changing citizens’ perceptions about disaster response as the citizens’ felt more prepared during the second typhoon. Some of the respondents who answered “other” wished to have improved sewage systems rather than flood protections.
Flow-induced vibration of a radial gate at various opening heights
Published in Engineering Applications of Computational Fluid Mechanics, 2018
Seung Oh Lee, Hoje Seong, Jun Won Kang
Radial gates are a type of radial arm floodgate used in dams and canal locks to control water flow. They are the most common type of spillway gate in use today and consist of a curved skin plate supported by a structural steel frame. They play an important role in mitigating flooding, utilizing water, and maintaining river environments. Although radial gates are manufactured to have sufficient stiffness for the design water pressure, large vibrations can be produced due to the vortices generated by water pressure fluctuation during discharge. Excessive vibration can cause fatigue failure in radial-gate connectors; therefore, it is necessary to both investigate vibration-reduction methods for the gate during operation and confirm safe operation with respect to the design water pressure. The radial gates of Wachi Dam in Japan and the Folsom Dam in the United States (US) were destroyed due to the vortex-induced vibrations generated when the gates were partially opened in 1967 and 1995, respectively (Figure 1).