The Severity of Severe Events is Increasing

On Thursday night, Mary Catherine Cochran, executive director of the Patapsco Heritage Greenway, asked some very insightful questions about my analysis of flooding in Ellicott City: These questions are worth going into some detail, so let me now discuss what it means that the data is changing. Data is considered to be stationary if it is random and if the characteristics from randomness, such as mean and variance, do not change over time. You can kind of think of this like a bus schedule. Sometimes the bus comes on time. Sometimes it is late. Sometimes, it is even early. However,

What is a 100-year flood?

Last night, Mary Catherine Cochran, executive director of the Patapsco Heritage Greenway, asked some very insightful questions about my analysis of flooding in Ellicott City: These questions are worth going into some detail, so let me begin by discussing first, how I account for changing statistics. The answer is, I don’t, but that doesn’t matter. The how is interesting, but the why is critical to understanding both severe storms and rare events. There’s a common misconception that the “100-year flood” is what happens whenever any flood event happens. You often hear any flood described as a 100-year flood, but that’s

Statistical Likelihood of Extreme Events and the Ellicott City Floods

This time, the flood hit close to home, literally. Over the last week, Ellicott City has responded after a very bad storm dropped nearly six inches of rain in only two hours. The recovery effort will be long and difficult, but the Ellicott City Partnership has done a remarkable job coordinating resources for both immediate and long term needs. The storm and its effects were severe and Ellicott City will require strong leadership, going forward. However, there’s been some accusations and finger pointing, about who may be responsible for inflicting what damage. The evidence given is usually the gross severity

FEMA’s Flood Maps Are Not a Scam

On May 3rd, this article ran in the Hamilton Journal-News. Hamilton fights federal government on flood hazard area AFFECTED PROPERTIES Most of the properties affected are west of where Two Mile Creek passes under Cleveland Avenue and east of Haverhill Drive. Long and short is, local business owner Mike Day was quoted as saying, “It just seems to be one more government-intrusive cost that I would have to end up paying because someone deems it necessary, that has probably never stepped foot on this street.” 1 The quote bothered me enough, that I posted it on Facebook leading to some

Flood Insurance Profits? Maybe Not

NPR has made a lot out of a report that insurance companies made $400 million in profit from flood insurance. This does not seem likely. When I wrote my text on flood insurance, I was unable to disaggregate profit numbers. Also, some of the figures given in the NPR report are simply incorrect. For instance, they show that 1/3 of premiums go to insurances companies. Insurance companies receive 15% to manage record keeping, sales, and claims processing. In addition, companies that sell well get up to 2% more, capping the amount insurance companies are paid at half of the 1/3rd