What is the rational method?

What is the rational method?

The Rational Method expresses a relationship between rainfall intensity and catchment area as independent variables and the peak flood discharge resulting from the rainfall as the dependent variable. It has been used for over 150 years, and known as the Rational Method for nearly 100 years.

What is the difference between the rational method and the Modified Rational Method?

With the traditional Rational Method, the peak flow of each drainage area (catchment) is based on its individual time of concentration. With the Modified Rational method, there is a single “storm duration” (and thus intensity) applied to all drainage areas.

How do you calculate the runoff coefficient?

A = catchment area (ha). The runoff coefficient (Cy) is defined as the ratio of the peak runoff rate of a given ARI to the mean rate of rainfall for a duration equal to the catchment ‘time of concentration’ and of the same ARI.

What is rational method in research?

Rational method is based on experimental idea proposing that the highest runoff produced in the stream is reliant on the watershed area that gives to the flow in the stream, and assuming that depth of runoff produced from the basin is a ratio of amount of rainfall.

What is the advantage of rational method?

Advantages. The rational approach to decisions is based on scientifically obtained data that allow informed decision-making, reducing the chances of errors, distortions, assumptions, guesswork, subjectivity, and all major causes for poor or inequitable judgments.

How do you use the rational method?

The Rational method predicts the peak runoff according to the formula: Q=CiA, where C is a runoff coefficient, i is the rainfall intensity, and A is the subcatchment area. This formula is applicable to US or metric evaluation, as long as consistent units are employed.

Who developed the rational method?

The Rational Method is a simple technique for estimating a design discharge from a small watershed . 2 It was developed by Kuichling (1889) for small drainage basins in urban areas.

How do you calculate annual runoff?

To calculate the runoff from any given rainfall:

1. Take the dimensions of the footprint of your roof and convert them to inches. (So, a 50′ x 20′ roof is 600″ x 240″.)
2. Multiply the roof dimensions by the number of inches of rainfall. (In this example, 600″ x 240″ x 1″ = 144,000 cubic inches of water.)

When can the rational method be used?

One of the most commonly used procedures for calculating peak flows from small drainages less than 200 acres is the Rational Method. This method is most accurate for runoff estimates from small drainages with large amounts of impervious area. Examples are housing developments, industrial areas, parking lots, etc.

What are disadvantages of rational choice theory?

A limitation of rational choice theory is that it focuses on individual action. While one could say that individual action drives large social structures, some rational choice theory critics argue the theory is too limited in its explanation.

What are the limits of rational decision making?

The rationality of individuals is limited, however, by the information they have, the cognitive limitations of their minds, and the finite amount of time they have to make a decision. To account for these limitations, alternative models of decision making offer different views of how people make choices.

What does AR mean in reading?

AR stands for Accelerated Reader, which is a reading system used in many grade schools and created by Renaissance Learning. Basically, AR is a software assessment program which determines whether children have read certain books by asking them between 5-20 multiple choice questions about them.

What is the AR website?

Accelerated Reader (AR) is software for K-12 schools for monitoring the practice of reading. It was developed by Renaissance Learning, Inc. There are two versions: a desktop version and a web-based version in Renaissance Place , the company’s online portal.

How do you take an AR test?

At school we take a ar test every day how do I take one at home. Type in take an ar test.com click student type in your user name. By going on google and put take ar test. Yes yo can by calling your school. Ask mrs.hancock and take a test. Central primary school suck and their poor.

Where can you find AR books?

Many of the AR books can be found as traditional books in Puyallup Public Library’s catalog. Some books can also be found as eBooks or downloadable audiobooks on the Washington Anytime Library website.