Estimating Average Rainfall

Asked by: Kira Huntington

The grid point precipitation value is calculated based on the sum of the individual station weight multiplied by observed station value. Once the grid points have all been estimated they are summed and the sum is divided by the number of grid points to obtain the areal average precipitation.

How do you calculate the average rainfall of an area?

Add together all of the monthly rainfall totals in your sample data. You’ll be adding measurements in inches because rainfall is generally measured in inches in the United States. Divide by the number of years in your data set to arrive at the average monthly rainfall for any location.

What is the formula for calculating rainfall?

Find the average volume of rain = Depth x radius x radius x 3.14. Find the area at the top of the bucket (this is the area over which the rain is collected). Divide the rainfall volume by this area to get the rainfall.

How do you calculate average rainfall per hour?

If all available is monthly average in mm, take the monthly average and divide by number of hours in that month. So if you had 300 mm in April, take 360 mm/(30 days * 24 hours) = 0.5 mm/hour average monthly intensity.

How can I calculate average?

Average This is the arithmetic mean, and is calculated by adding a group of numbers and then dividing by the count of those numbers. For example, the average of 2, 3, 3, 5, 7, and 10 is 30 divided by 6, which is 5. Median The middle number of a group of numbers.

Which is the method of finding out average annual rainfall of a catchment?

The isohyetal method is used to estimate the mean precipitation across an area by drawing lines of equal depth rainfall (called isohyets) and calculating the areas enclosed either between the isohyets or between isohyets and the catchment boundary.

How do you calculate average precipitation in Excel?

Quote from video: Such as average salary. And average hours that can be done very quickly all we have to do is select the cell that we want the first average to appear click the equal sign as we do with all formulas.

How do you calculate rainfall on a roof?

Roughly speaking, 1 millimetre of rain over 1 square metre of roof equals 1 litre of water. This capacity can be calculated using the following formula: Annual rainfall (in millimetres) x Roof surface area (in square metres) = Roof catchment capacity.

How do you calculate rainfall in mm per hour?

DEFINITIONS

1. Violent rain: If 2” of rain have fallen in 10 minutes, then the equivalent rainfall rate in terms of in/hr will be 60 min / 10 min * 2” of rain = 12 in/hr.
2. Heavy rain: If 15 mm of rain have fallen in 30 minutes, then the equivalent rain rate in terms of mm/hr will be 60 min / 30 min * 15 mm of rain = 30 mm/hr.

How do you analyze daily rainfall data?

For statistical analysis rainfall data from a single series should ideally possess property of homogeneity – i.e. properties or characteristics of different portion of the data series do not vary significantly. Rainfall data for multiple series at neighbouring stations should ideally possess spatial homogeneity.

How much is 1 inch of rain in gallons?

Volume and weight



One inch of rain falling on 1 acre of ground is equal to about 27,154 gallons and weighs about 113 tons. An inch of snow falling evenly on 1 acre of ground is equivalent to about 2,715 gallons of water.

What are the three methods for determining areal average rainfall using rainfall gauge data?

Read this article to learn about the following three methods of calculating average depth of precipitation upon the area of the basin, i.e., (1) Arithmetic Mean, (2) Theissen Polygon Method, and (3) Iso-Hyetal Method.

Which is the most suitable method for estimating average rainfall in hilly and uneven catchment area?

Most accurate method for estimating mean rainfall over a catchment,is : A. arithmetic mean method.

Which method gives accurate estimate?

Quote from video: Похожие запросы

How do you calculate average precipitation in Excel?

Quote from video: Such as average salary. And average hours that can be done very quickly all we have to do is select the cell that we want the first average to appear click the equal sign as we do with all formulas.

What is the annual mean rainfall?

Mean Annual Rainfall means the average total amount of rainfall recorded during a year in a particular place.

How do you calculate average temperature?

Take the temperature readings on the hour for a 24-hour period. Add the hourly readings together, then divide that number by 24 to get the mean daily temperature.

Why do we calculate average?

Why do we calculate average? We calculate averages because they are a very useful way to present a large amount of data. Instead of having to trawl through hundreds or thousands of pieces of data, we have one number that succinctly summarises the whole set.

How do we calculate the average weather of a place in a week?

The calculation for one week is as follows: Add up the seven daily highs and the seven daily lows, and then divide the sum by the number of entries, 14 in this case.