# Question: What methods are there to estimate average rainfall?

1) arithmetic mean – This technique calculates areal precipitation using the arithmetic mean of all point or area measurements considered in the analysis. 2) Isohyetal Analysis – This is a graphical technique that draws estimated lines of equal rainfall over an area based on point measurements.

## What are the methods of calculating average precipitation?

Measuring the average amount of precipitation: 3 methods | Atmosphere | Geography

• The Arithmetic Mean Method: The simplest of all is the arithmetic mean method, which takes an average of all precipitation amounts as shown in Fig.
• The Thiessen polygon method:
• The Isohyetal Method:

## What methods are there to determine the average amount of precipitation over an area?

Estimation of the average amount of precipitation

• Arithmetic Mean Method: This is the simplest method where the average precipitation amount is obtained by taking the sum of the precipitation amounts (eg1P2P3P4…………….
• Polygon method according to Theissen:
• Isohyetal method:

## Which 4 methods for areal precipitation estimation are there?

This problem is illustrated below where avg P needs to be estimated over the entire basin from measured 1P, 2P, 3P and 4P. We will discuss four methods: 1) Arithmetic Mean, 2) Theissen Polygons, 3) Isohyetal Method and 4) Grid Method.

## How many methods are used to determine average rainfall by drainage basin?

Explanation: When there are more basins, three of the following methods are used to determine the average rainfall as a function of basin area. They are the arithmetic mean method, the Thiesson method and the Iso-Hyetol method.

## Which method provides an accurate estimate of the average rainfall in the catchment area of ​​hilly area?

The isohyetal method is used to estimate mean precipitation over an area by drawing lines of equal precipitation.

## What is the Thiessen polygon method?

A method for assigning area importance to point precipitation values. These bisecting lines form a series of polygons, each polygon containing a station. The precipitation value measured at a station is assigned to the entire area of ​​the enclosing polygon.

## What methods are there to estimate missing precipitation data?

The following methods are most commonly used to estimate the missing records.

• Simple arithmetic method.
• method of normal ratio.
• Modified normal ratio method.
• Inverse distance method.
• Linear programming method.

## How is the amount of precipitation measured?

The standard instrument for measuring precipitation is the 203 mm (8 inch) rain gauge. This is essentially a circular 203mm diameter funnel that collects the rain in a graduated and calibrated cylinder. The measuring cylinder can record up to 25 mm of precipitation.

## What is the average areal precipitation?

Precipitation in a given area, expressed as the average depth of liquid water over the area; the average amount of precipitation over a given area, calculated on time scales on a storm, seasonal, or annual basis.

## What is the best method for determining mean annual precipitation?

To determine the mean annual precipitation in a catchment area, the isohytated method is the best method.

## What are the 8 types of precipitation?

The different types of precipitation are:

• Rain. Most commonly observed, drops larger than drizzle (0.02 inch / 0.5 mm or more) are considered rain.
• drizzle. Fairly uniform precipitation consisting entirely of very densely packed fine droplets.
• Ice pellets (sleet)
• Hail.
• Small hail (snow pellets)
• Snow.
• grains of snow.
• ice crystals.

## Why is the Isohyetal method better than the Thiessen polygon method?

Answer: The isohyetal method is considered more accurate than the Thiessen polygon method or the gridpoint technique for estimating precipitation totals because it takes into account the effects of local features.