A rain gauge is really just a cylinder that catches rain. If an inch collects in the cylinder, it means an inch of rain has fallen. ... Most standard rain gauges have a wide funnel leading into the cylinder and are calibrated so that one-tenth of an inch of rain measures one inch when it collects inside.
What is meant by 1 inch of rain?
Rainfall amount is described as the depth of water reaching the ground, typically in inches or millimeters (25 mm equals one inch). An inch of rain is exactly that, water that is one inch deep . One inch of rainfall equals 4.7 gallons of water per square yard or 22,650 gallons of water per acre!
What is the volume of 1 inch of rain?
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.
Why is rain measured in inches?
The inner tube’s diameter is just small enough to make the depth of rain ten times what it would be in a gauge without the tube and funnel. Thus, each inch in the tube is equivalent to 0.1 inches (a tenth of an inch) of rainfall. This makes it easier to read accurately!
How the rain is measured?
The standard instrument for the measurement of rainfall is the 203mm (8 inch) rain gauge . This is essentially a circular funnel with a diameter of 203mm which collects the rain into a graduated and calibrated cylinder. The measuring cylinder can record up to 25mm of precipitation.
What does 1 inch of rain look like?
One (1.00) inch of rain – A light moderate rain never reaches this amount, heavy rain for several hours (2-5 hours). There would be deep standing water for long periods of time.
Is rain measured in cubic inches?
From other sources on the web, the basic idea is that the area of the collection is given in squared units of length( e.g. square inches) and the volume of rain is measured in cubed units of length (e.g. cubic inches). ... So a reading of “1 inch” of rainfall means 1 cubic inch of rain fell per square inch of ground.
Does the size of a rain gauge matter?
The larger the opening, the lower the statistical error in measurements in real-world applications. Always choose the largest size that your budget allows . Rain gauge resolution determines the smallest amount of precipitation that one is able to measure and the accuracy of short-term rain intensity measurements.
Who invented rain gauge?
Rain gauges are one of the most ancient weather instruments. The ancient Greeks and people in India were the first known to keep rainfall records, about 400–500 BC. In 1441, Korea invented the first standardised rain gauge, the Cheugugi.
How is rain water calculated?
You must know the approximate dimensions of the water collection surface, most commonly a roof. A typical roof area can provide surprising amounts of water. For example, one inch of rainfall on a roof that is 20 feet by 20 feet can provide 220 gallons of rainwater.
Is code for rain gauge?
Instruments. The standard instrument for the measurement of rainfall is the 203mm (8 inch) rain gauge. This is essentially a circular funnel with a diameter of 203mm which collects the rain into a graduated and calibrated cylinder. The measuring cylinder can record up to 25mm of precipitation.
How is rain measured in cm?
The amount of rainfall is expressed as depth in centimeters (or millimeters) which falls on a level surface. Intensity of rainfall is the rate at which it falls at any one time. It is expressed as cm per hour or mm per hour. Rainfall is measured by means of rain gauges .
How does rain fall?
Raindrops fall to Earth when clouds become saturated, or filled, with water droplets . Millions of water droplets bump into each other as they gather in a cloud. When a small water droplet bumps into a bigger one, it condenses, or combines, with the larger one.
Can 1 inch of rain cause flooding?
Floods can happen during heavy rains , when ocean waves come on shore, when snow melts quickly, or when dams or levees break. Damaging flooding may happen with only a few inches of water, or it may cover a house to the rooftop. ... Flash floods occur when heavy rainfall exceeds the ability of the ground to absorb it.
What is considered heavy rainfall?
Slight rain: Less than 0.5 mm per hour. Moderate rain: Greater than 0.5 mm per hour, but less than 4.0 mm per hour. Heavy rain: Greater than 4 mm per hour, but less than 8 mm per hour . Very heavy rain: Greater than 8 mm per hour.
How much does 1 inch of rain raise a lake?
For this particular event, though, and given the particular antecedent conditions, we come up with the following ratios. For Falls Lake, we saw about a 2.6 inch rise for each inch of rain .
