Published on 6 Mar 2016
Today on Practical Engineering we’re talking about hydrology, and I took a little walk through my neighborhood to show you some infrastructure you may have never noticed before.
Almost everyone agrees that flooding is bad. Most years it’s the number one natural disaster in the US by dollars of damage. So being able to characterize flood risks is a crucial job of civil engineers. Engineering hydrology has equal parts statistics and understanding how society treats risks. Water is incredibly important to us, and it shapes almost every facet of our lives, but it’s almost never in the right place at the right time. Sometimes there’s not enough, like in a drought or just an arid region, but we also need to be prepared for the times when there’s too much water, a flood. Rainfall and streamflow have tremendous variability and it’s the engineer’s job to characterize that so that we can make rational and intelligent decisions about how we develop the world around us. Thanks for watching!
FEMA Floodplain Maps: https://msc.fema.gov/portal
USGS Stream Gages: http://maps.waterdata.usgs.gov/mapper
September 5, 2017
The 100 Year Flood Is Not What You Think It Is (Maybe)
Georges Guynemer – The Flying Icon of France I WHO DID WHAT IN WW1?
Published on 4 Sep 2017
George Guynemer was one of the top scoring flying aces of the entire First World War with 54 aerial victories. In his lifetime, he was celebrated as a hero, an icon and an inspiration in France. When he went missing 100 years ago, in September 1917, it was a great shock to the nation and to this day his death is not fully understood.
“So, let’s consider the concept of a ‘500-year flood'”
Charlie Martin explains how it’s possible to have two “500-year floods” in less than 500 years:
There have been a lot of people suggesting that Harvey the Hurricane shows that “really and truly climate change is happening, see, in-your-face deniers!”
Of course, it’s possible, even though the actual evidence — including the 12-year drought in major hurricanes — is against it. But hurricanes are a perfect opportunity for stupid math tricks. Hurricanes also provide great opportunities to explain concepts that are unclear to people. So, let’s consider the concept of a “500-year flood.”
Most people hear this and think it means “one flood this size in 500 years.” The real definition is subtly different: saying “a 500-year flood” actually means “there is one chance in 500 of a flood this size happening in any year.”
It’s called a “500-year flood” because statistically, over a long enough time, we would expect to have roughly one such flood on average every 500 years. So, if we had 100,000 years of weather data (and things stayed the same otherwise, which is an unrealistic assumption) then we’d expect to have seen 100,000/500- or 200 500-year floods [Ed. typo fixed] at that level.
The trouble is, we’ve only got about 100 years of good weather data for the Houston area.
Tank Chats #18 Mark I
Published on 15 Apr 2016
David Fletcher has returned to host the latest Tank Chat, on the Mark I tank.
The Museum’s Mark I is the only surviving example of this, the first tank produced to go into battle.
Find out more about the First World War on the Tank Museum’s Centenary blog, Tank 100 http://www.tank100.com
QotD: Microaggressions
Whenever I first heard the word “microaggression,” sometime in the last five years, I’m sure I was unaware how big “micro” could get. The accusation of a microaggression was about to become a pervasive feature of the Internet, and particularly social media. An offense most of us didn’t even know existed, suddenly we were all afraid of being accused of.
We used to call this “rudeness,” “slights” or “ignorant remarks.” Mostly, people ignored them. The elevation of microaggressions into a social phenomenon with a specific name and increasingly public redress marks a dramatic social change, and two sociologists, Bradley Campbell and Jason Manning, have a fascinating paper exploring what this shift looks like, and what it means. (Jonathan Haidt has provided a very useful CliffsNotes version.)
Western society, they argue, has shifted from an honor culture — in which slights are taken very seriously, and avenged by the one slighted — to a dignity culture, in which personal revenge is discouraged, and justice is outsourced to third parties, primarily the law. The law being a cumbersome beast, people in dignity cultures are encouraged to ignore slights, or negotiate them privately by talking with the offender, rather than seeking some more punitive sanction.
Microagressions mark a transition to a third sort of culture: a victim culture, in which people are once again encouraged to take notice of slights. This sounds a lot like honor culture, doesn’t it? Yes, with two important differences. The first is that while victimhood is shameful in an honor culture — and indeed, the purpose of taking vengeance is frequently to avoid this shame — victim status is actively sought in the new culture, because victimhood is a prerequisite for getting redress. The second is that victim culture encourages people to seek help from third parties, either authorities or the public, rather than seeking satisfaction themselves.
Megan McArdle, “How Grown-Ups Deal With ‘Microaggressions'”, Bloomberg View, 2015-09-11.
