W-Index Calculator

✖Total Storm Precipitation is the annual precipitation of the current year.ⓘ Total Storm Precipitation [P]			+10% -10%
✖Total Storm Runoff is rain that flows off building rooftops, driveways, lawns, streets, parking lots, construction sites, and industrial storage yards.ⓘ Total Storm Runoff [R]			+10% -10%
✖Depression and Interception Losses is the portion of the precipitation that is returned to the atmosphere through evaporation from plant surfaces .ⓘ Depression and Interception Losses [I_a]			+10% -10%
✖Duration of Rainfall Excess is the total time in which the rainfall intensity the greater than the average rate of infiltration (in hours).ⓘ Duration of Rainfall Excess [t_e]			+10% -10%

✖W-Index is the average infiltration rate during the time when the rainfall intensity exceeds the infiltration rate.ⓘ W-Index [W]

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W-Index Solution

STEP 0: Pre-Calculation Summary

Formula Used

W-Index = (Total Storm Precipitation-Total Storm Runoff-Depression and Interception Losses)/Duration of Rainfall Excess
W = (P-R-I_a)/t_e
This formula uses 5 Variables

Variables Used

W-Index - (Measured in Centimeter) - W-Index is the average infiltration rate during the time when the rainfall intensity exceeds the infiltration rate.
Total Storm Precipitation - (Measured in Centimeter) - Total Storm Precipitation is the annual precipitation of the current year.
Total Storm Runoff - (Measured in Centimeter) - Total Storm Runoff is rain that flows off building rooftops, driveways, lawns, streets, parking lots, construction sites, and industrial storage yards.
Depression and Interception Losses - (Measured in Centimeter) - Depression and Interception Losses is the portion of the precipitation that is returned to the atmosphere through evaporation from plant surfaces .
Duration of Rainfall Excess - (Measured in Hour) - Duration of Rainfall Excess is the total time in which the rainfall intensity the greater than the average rate of infiltration (in hours).

STEP 1: Convert Input(s) to Base Unit

Total Storm Precipitation: 118 Centimeter --> 118 Centimeter No Conversion Required
Total Storm Runoff: 48 Centimeter --> 48 Centimeter No Conversion Required
Depression and Interception Losses: 6 Centimeter --> 6 Centimeter No Conversion Required
Duration of Rainfall Excess: 4 Hour --> 4 Hour No Conversion Required

STEP 2: Evaluate Formula

Substituting Input Values in Formula

W = (P-R-I_a)/t_e --> (118-48-6)/4

Evaluating ... ...

W = 16

STEP 3: Convert Result to Output's Unit

0.16 Meter -->16 Centimeter (Check conversion here)

FINAL ANSWER

16 Centimeter <-- W-Index

(Calculation completed in 00.004 seconds)

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Home » Engineering » Civil » Engineering Hydrology » Abstractions from Precipitation » Infiltration Indices » W Index » W-Index

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Created by Mithila Muthamma PA

Coorg Institute of Technology (CIT), Coorg

Mithila Muthamma PA has created this Calculator and 2000+ more calculators!

Verified by Chandana P Dev

NSS College of Engineering (NSSCE), Palakkad

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< W Index Calculators

Total Storm Precipitation when W Index

LaTeX Go Total Storm Precipitation = (W-Index*Duration of Rainfall Excess)+Total Storm Runoff+Depression and Interception Losses

Total Storm Runoff given W Index

LaTeX Go Total Storm Runoff = Total Storm Precipitation-Depression and Interception Losses-(W-Index*Duration of Rainfall Excess)

Initial Losses given W-Index

LaTeX Go Depression and Interception Losses = Total Storm Precipitation-Total Storm Runoff-(W-Index*Duration of Rainfall Excess)

W-Index

LaTeX Go W-Index = (Total Storm Precipitation-Total Storm Runoff-Depression and Interception Losses)/Duration of Rainfall Excess

W-Index Formula

LaTeX Go

W-Index = (Total Storm Precipitation-Total Storm Runoff-Depression and Interception Losses)/Duration of Rainfall Excess
W = (P-R-I_a)/t_e

What is W-Index?

W-Index is the average infiltration rate during the time when the rainfall intensity exceeds the infiltration rate. Thus, W may be mathematically calculated by dividing the total infiltration. (expressed as a depth of water) divided by the time during which the rainfall occurs.

What is W_min ?

The minimum value of the W-index obtained under very wet soil conditions, representing the constant minimum rate of infiltration of the catchment, is known as Wmin.

How to Calculate W-Index?

W-Index calculator uses W-Index = (Total Storm Precipitation-Total Storm Runoff-Depression and Interception Losses)/Duration of Rainfall Excess to calculate the W-Index, The W-Index formula is defined as the average infiltration rate during the time when the rainfall intensity exceeds the infiltration rate. W-Index is denoted by W symbol.

How to calculate W-Index using this online calculator? To use this online calculator for W-Index, enter Total Storm Precipitation (P), Total Storm Runoff (R), Depression and Interception Losses (I_a) & Duration of Rainfall Excess (t_e) and hit the calculate button. Here is how the W-Index calculation can be explained with given input values -> 1600 = (1.18-0.48-0.06)/14400.

FAQ

What is W-Index?

The W-Index formula is defined as the average infiltration rate during the time when the rainfall intensity exceeds the infiltration rate and is represented as W = (P-R-I_a)/t_e or W-Index = (Total Storm Precipitation-Total Storm Runoff-Depression and Interception Losses)/Duration of Rainfall Excess. Total Storm Precipitation is the annual precipitation of the current year, Total Storm Runoff is rain that flows off building rooftops, driveways, lawns, streets, parking lots, construction sites, and industrial storage yards, Depression and Interception Losses is the portion of the precipitation that is returned to the atmosphere through evaporation from plant surfaces & Duration of Rainfall Excess is the total time in which the rainfall intensity the greater than the average rate of infiltration (in hours).

How to calculate W-Index?

The W-Index formula is defined as the average infiltration rate during the time when the rainfall intensity exceeds the infiltration rate is calculated using W-Index = (Total Storm Precipitation-Total Storm Runoff-Depression and Interception Losses)/Duration of Rainfall Excess. To calculate W-Index, you need Total Storm Precipitation (P), Total Storm Runoff (R), Depression and Interception Losses (I_a) & Duration of Rainfall Excess (t_e). With our tool, you need to enter the respective value for Total Storm Precipitation, Total Storm Runoff, Depression and Interception Losses & Duration of Rainfall Excess and hit the calculate button. You can also select the units (if any) for Input(s) and the Output as well.

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W-Index Calculator

W-Index Solution

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< W Index Calculators

W-Index Formula

What is W-Index?

What is Wmin ?

How to Calculate W-Index?

FAQ

What is W_min ?