20 Liters per cubic meter of rain?

In summary, the conversation was about the measurement of rainfall in different units and how it can be confusing or misleading. The initial report stated 20 liters per cubic meter of rain, which caused confusion and speculation about the actual amount of rainfall. The conversation also touched on the topic of reporting rainfall in terms of volume rather than height and whether it makes sense or not. Ultimately, it was agreed that the most important factor is providing a measurement that is easy for the public to understand.
  • #1
Chiclayo guy
41
3
20 Liters per cubic meter of rain?

A weather report for Chiclayo Peru said we received 20 liters per cubic meter of rain yesterday. How many inches of rain would a New York weather report say we received? Thanks.

Tom
 
Mathematics news on Phys.org
  • #2


The report (as you stated) can't be translated. If it were liters per square meter, then you can calculate the height. Assuming my interpretation, you have 2x104 cc of rain on an area of 104 sq cm.
This gives a height of 2 cm, approx. 0.8 in.
 
  • #3


I just saw the report again and they did say 20 liters per cubic meter (which has caused wide-spread flooding here). But intuitively the figure you arrived at of 0.8 inches feels in the ball park. It fell in a 24 hour period and given conditions here could have caused the flooding. Thanks for your response.

Tom
 
  • #4


Chiclayo guy said:
I just saw the report again and they did say 20 liters per cubic meter
Then the report had a typo :wink:
It doesn't make much sense to measure the height of a flooding rain in terms of cubic units.
 
  • #5


Mentallic said:
Then the report had a typo :wink:
It doesn't make much sense to measure the height of a flooding rain in terms of cubic units.
That's what I think, also.
 
  • #6


Mentallic said:
It doesn't make much sense to measure the height of a flooding rain in terms of cubic units.
It makes even less sense to report the quantity of rainfall as 0.02 -- and that is what 20 liters/meters3 is. It is a unitless number. Both liters and cubic meters are a measure of volume.
 
  • #7


You folks are correct...this internet article just showed up:

"Rains fell on Tumbes during 21 hours, leaving 35.4 liters per square meter, that turned streets into rivers, but fortunately caused no personal injuries, according to Civil Defense reports.

Chiclayo (Lambayeque) also suffered intense rains during six hours, that flooded the main avenues and affected some roads connecting to Cajamarca region."

Thanks for the responses.

Tom
 
  • #8


D H said:
It makes even less sense to report the quantity of rainfall as 0.02 -- and that is what 20 liters/meters3 is. It is a unitless number. Both liters and cubic meters are a measure of volume.
I disagree.
The public is only interested in a measurement of flooding that is simple to understand. 20mm rainfall makes sense as we only care how high the flooding is going to get. 20 L/m3 is less intuitive and only makes us have to do unnecessary mental calculations to convert this into something more understandable.
Of course we would get used to accepting the magnitude of such floods as 20L/m3 as we have with other non-intuitive measurements such as kilometres/hour, but again it's not a necessity to make these changes.

Also, what if the flooding were very intense and were to become over 1000mm? We would instead have something like 1500 Litres/metre3 and this makes even less sense.
 
  • #9


0.8 inches is not that much. The area near my house got 5 inches in 4 days a few weeks ago. It was wet, but there were no major disruptions.
 
  • #10


Mentallic said:
I disagree.
... 20 L/m3 is less intuitive and only makes us have to do unnecessary mental calculations to convert this into something more understandable.
Aren't there are always 1000 liters per m3, no matter how much rain has fallen? The m3 was clearly a typo, as the OP has confirmed.
 
  • #11


Mentallic said:
I disagree.
The public is only interested in a measurement of flooding that is simple to understand. 20mm rainfall makes sense as we only care how high the flooding is going to get. 20 L/m3 is less intuitive and only makes us have to do unnecessary mental calculations to convert this into something more understandable.
Of course we would get used to accepting the magnitude of such floods as 20L/m3 as we have with other non-intuitive measurements such as kilometres/hour, but again it's not a necessity to make these changes.

Also, what if the flooding were very intense and were to become over 1000mm? We would instead have something like 1500 Litres/metre3 and this makes even less sense.

You misunderstand the post you're disagreeing with. The figure of 0.02 is most definitely not 20mm when the 0.02 is dimensionless (Vol/Vol). That was DH's point.
 
  • #12


uart said:
You misunderstand the post you're disagreeing with.
Entirely possible.
The figure of 0.02 is most definitely not 20mm when the 0.02 is dimensionless (Vol/Vol). That was DH's point.
That I agree with.
 
  • #13


D H said:
Mentallic said:
It doesn't make much sense to measure the height of a flooding rain in terms of cubic units.
It makes even less sense to report the quantity of rainfall as 0.02 -- ...
uart said:
You misunderstand the post you're disagreeing with. The figure of 0.02 is most definitely not 20mm when the 0.02 is dimensionless (Vol/Vol). That was DH's point.
Yes you're right uart, I did misunderstand DH's post simply because the misleading part in bold made me think he was implying that the way the current system of rainfall measured in L/m2 made less sense that L/m3. DH misunderstood me, I misunderstood him. I think we've settled the problem :tongue:
 
  • #14


And I misunderstood who uart was telling that they misunderstood. (I hope that sentence was understandable.)
 

What does "20 Liters per cubic meter of rain" mean?

"20 Liters per cubic meter of rain" is a unit of measurement used to express the amount of rain that falls in a specific area. It means that for every cubic meter of land, there is 20 liters of rain that has fallen.

How is "20 Liters per cubic meter of rain" measured?

"20 Liters per cubic meter of rain" is typically measured using a rain gauge. This device collects rainwater and measures the amount in liters. The measurement is then divided by the area of the collection area, which is usually one square meter, to determine the amount of rain per cubic meter.

Is "20 Liters per cubic meter of rain" a lot of rain?

It depends on the location and climate. In some areas, 20 Liters per cubic meter of rain may be considered a significant amount, while in others it may be considered a small amount. Generally, 20 Liters per cubic meter of rain is considered to be a moderate amount of rainfall.

What factors can affect the amount of "20 Liters per cubic meter of rain" in an area?

The amount of "20 Liters per cubic meter of rain" can be affected by various factors such as topography, wind patterns, and air temperature. Higher elevation areas tend to receive more rain, while areas with mountains or hills can experience more localized rainfall. Wind patterns can also bring rain to certain areas, while others may experience less rainfall due to rain shadow. Additionally, warmer air temperatures can lead to more evaporation, resulting in less rain in certain areas.

How does "20 Liters per cubic meter of rain" impact the environment?

"20 Liters per cubic meter of rain" plays a crucial role in the environment. It helps replenish freshwater sources, nourishes plants and crops, and supports various ecosystems. However, excessive amounts of rain can also lead to flooding, erosion, and landslides, causing damage to the environment and human structures.

Similar threads

MHB Hurricane Harvey: Rapid Intensification, Expected to Make Landfall in 24 Hours
    • General Discussion
Replies
11
Views
3K
Ramjet artillery shell of a big size
    • Aerospace Engineering
2
Replies
35
Views
3K
How to convert Insulation Loss (in Watts/meter) to kWh energy savings per year?
    • Mechanical Engineering
Replies
13
Views
4K
How to calculate effective pump flow-rate across a filter?
    • Mechanical Engineering
Replies
2
Views
3K
I Questions on stars and planets: ratio of planet radius to star, distance between the two, temperature of a star and a planet, planet rotation speed
    • Astronomy and Astrophysics
Replies
12
Views
1K
Need help understanding pressure vs weather systems
    • Earth Sciences
Replies
4
Views
2K
A What volume of interstellar space is needed to form a star?
    • Cosmology
Replies
7
Views
2K
Role of future measurements on Bayes Filter
    • Set Theory, Logic, Probability, Statistics
Replies
4
Views
1K
How many alleles per gene the human species have today?
    • Biology and Medical
Replies
3
Views
2K
How to Calculate Weight on Pedals from Watts?
    • Mechanics
Replies
15
Views
3K

Hot Threads

Recent Insights

Back
Top