Impact of flood spill from A Vuong hydroelectricity reservoir on the inundation of Vu Gia-Thu Bon downstream.

Abstract

   On the Vu Gia - Thu Bon river basin system, numerous hydroelectricity reservoirs have been built or in progress, namely: A Vuong reservoir (operation since 2009), Dak Mi 4 reservoir, Song Tranh 2 (operation since 2011), Song Bung 2 and Song Bung 4. All the time, when the rainy season comes, there is always controversial about the flood spilling process of the aforementioned hydroelectricity reservoirs. After the flood even in 2009 coupled with No.9 storm named Ketsana, there were lots of arguments about the flood spilling process of A Vuong reservoir due to the serious impact on downstream flooding. In order to figure out the purpose of flood regulating operation related to the downstream flooding, in this paper, the author will re-simulate the flood event in 2009. Based on the simulating results with 3 distinctive scenarios, the author then evaluates the impact of flood spilling from A Vuong reservoir to the downstream flooding: - Vu Gia - Thu Bon river basin system, Flood from A Vuong reservoir is spilled with the happened discharge in flood event 2009. - Without A Vuong reservoir. - A Vuong reservoir spill flood discharge as the author proposes.