How do you choose a return period?

How do you choose a return period?

The choice of return period depends on various factors, including: (a) the size of the drainage area, (b) the risk of failure, (c) the importance of the structure, and (d) the desired degree of conservatism in the design.

What is average return period?

Average return is the mathematical average of a sequence of returns that have accrued over time. In its simplest terms, average return is the total return over a time period divided by the number of periods.

What is rain return period?

Simply stated, a return period is an estimate of how long it will be between rainfall events of a given magnitude. For example, the return period for a 3-hour rainfall total of 4.25 inches in Oklahoma City is 25 years.

What is return period of wind?

The probability that events such as floods, wind storms or tornadoes will occur is often expressed as a return period. The inverse of probability (generally expressed in %), it gives the estimated time interval between events of a similar size or intensity.

Why is return period important?

Return period is useful for risk analysis (such as natural, inherent, or hydrologic risk of failure). When dealing with structure design expectations, the return period is useful in calculating the riskiness of the structure.

What is return level?

From the fitted distribution, we can estimate how often the extreme quantiles occur with a certain return level. The return value is defined as a value that is expected to be equaled or exceeded on average once every interval of time (T) (with a probability of 1/T).

What is a good average rate of return?

Expectations for return from the stock market Most investors would view an average annual rate of return of 10% or more as a good ROI for long-term investments in the stock market. However, keep in mind that this is an average. Some years will deliver lower returns — perhaps even negative returns.

What is a 100 year return period?

Let’s look at the term “return period,” also referred to as the “recurrence interval.” The return period is the time period over which it is likely that a particular magnitude flood will occur. Thus, a 100-year flood is defined as a flood that can occur on average once every 100 years.

What is a 10-year return period?

The return period is defined as the average period of time expected to elapse between occurrences of events at a certain site. A 10-year event is an event of such size that over a long period of time, the average time between events of equal or greater magnitude is 10 years.

What is a 20 year return period?

They describe how likely a hazard event is to occur at, or above, a specific intensity within a time frame defined by a probability. A longer return period (for example, 100 vs. 20 years) suggests a lower probability that an extreme hazard will occur in any single year.

What is a 50 year return period?

So in this case we could say that the reservoir is designed to a 1:50 year return period, sometimes expressed as a 2% or 0.02 chance. This means that it should not fail during an event which occurs on average once every 50 years.

What is return level in extreme value theory?