Dam and flood control

Hi Mr. Tan

I was very surprised to see a news clip from CNA a few hours ago today (16 Jul 2010). It said that to prevent floods, the Chinese government used explosives to blast open a dam. I saw the video footage and it was
awesome!! The dam must have been incorrectly constructed, i thought in my naive mind!!

I went to internet to try to research on flood control, it seems to be a very technical and academic subject, i have difficulty understanding what is a dam, what is a levee, what is a barrage, and especially why blast open a dam, and how floods can happen. (i didn't see anything to say that massive floods occur because of blocked culverts)

I wonder if there are any experts reading your blog who could lend some help to interprete the reasons for the floods in singapore recently, and also how come a dam in china has need to be destroyed if floods are meant
for flood control? CNA news clip didnt elaborate on the issue, from the layman point of view, it seems like the dam is blocking flow of water out to sea, so blast it up.  Isn't our Marina Barrage a dam too?  What's the difference? Are there independent experts willing to share some knowledge?

rex


Any knowledgeable person can contact rex at rex@humbleideas.com