Change in Drawdown given Discharge Calculator

✖The Discharge refers to the volumetric flow rate of water that is transported through a given cross-sectional area. It includes any suspended solids, dissolved chemicals, or biologic material.ⓘ Discharge [Q]			+10% -10%
✖The Radial Distance at Observation Well 2 refers to the refers to the horizontal distance from the center of a pumping well to the observation well.ⓘ Radial Distance at Observation Well 2 [r₂]			+10% -10%
✖The Radial Distance at Observation Well 1 refers to the refers to the horizontal distance from the center of a pumping well to the observation well.ⓘ Radial Distance at Observation Well 1 [r₁]			+10% -10%
✖The Transmissivity of an Unconfined Aquifer refers to the ability of the aquifer to transmit groundwater throughout its entire saturated thickness.ⓘ Transmissivity of an Unconfined Aquifer [T]			+10% -10%

✖The Change in Drawdown refers to the maximum lowering of the groundwater table caused by pumping or artesian flow.ⓘ Change in Drawdown given Discharge [s]

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Change in Drawdown given Discharge Solution

STEP 0: Pre-Calculation Summary

Formula Used

Change in Drawdown = Discharge*ln(Radial Distance at Observation Well 2/Radial Distance at Observation Well 1)/2*pi*Transmissivity of an Unconfined Aquifer
s = Q*ln(r₂/r₁)/2*pi*T
This formula uses 1 Constants, 1 Functions, 5 Variables

Constants Used

pi - Archimedes' constant Value Taken As 3.14159265358979323846264338327950288

Functions Used

ln - The natural logarithm, also known as the logarithm to the base e, is the inverse function of the natural exponential function., ln(Number)

Variables Used

Change in Drawdown - (Measured in Meter) - The Change in Drawdown refers to the maximum lowering of the groundwater table caused by pumping or artesian flow.
Discharge - (Measured in Cubic Meter per Second) - The Discharge refers to the volumetric flow rate of water that is transported through a given cross-sectional area. It includes any suspended solids, dissolved chemicals, or biologic material.
Radial Distance at Observation Well 2 - (Measured in Meter) - The Radial Distance at Observation Well 2 refers to the refers to the horizontal distance from the center of a pumping well to the observation well.
Radial Distance at Observation Well 1 - (Measured in Meter) - The Radial Distance at Observation Well 1 refers to the refers to the horizontal distance from the center of a pumping well to the observation well.
Transmissivity of an Unconfined Aquifer - (Measured in Square Meter per Second) - The Transmissivity of an Unconfined Aquifer refers to the ability of the aquifer to transmit groundwater throughout its entire saturated thickness.

STEP 1: Convert Input(s) to Base Unit

Discharge: 1.3 Cubic Meter per Second --> 1.3 Cubic Meter per Second No Conversion Required
Radial Distance at Observation Well 2: 10 Meter --> 10 Meter No Conversion Required
Radial Distance at Observation Well 1: 5 Meter --> 5 Meter No Conversion Required
Transmissivity of an Unconfined Aquifer: 0.703 Square Meter per Second --> 0.703 Square Meter per Second No Conversion Required

STEP 2: Evaluate Formula

Substituting Input Values in Formula

s = Q*ln(r₂/r₁)/2*pi*T --> 1.3*ln(10/5)/2*pi*0.703

Evaluating ... ...

s = 0.995047963964231

STEP 3: Convert Result to Output's Unit

0.995047963964231 Meter --> No Conversion Required

FINAL ANSWER

0.995047963964231 ≈ 0.995048 Meter <-- Change in Drawdown

(Calculation completed in 00.020 seconds)

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< Unconfined Flow by Dupit's Assumption Calculators

Water Table Profile Neglecting Depths of Water in Drains

LaTeX Go Water Table Profile = sqrt((Natural Recharge/Coefficient of Permeability)*(Length between Tile Drain-Flow in 'x' Direction)*Flow in 'x' Direction)

Discharge per Unit Width of Aquifer considering Permeability

LaTeX Go Discharge = ((Piezometric Head at Upstream End^2-Piezometric Head at Downstream End^2)*Coefficient of Permeability)/(2*Length between Upstream and Downstream)

Maximum Height of Water Table

LaTeX Go Maximum Height of Water Table = (Length between Tile Drain/2)*sqrt(Natural Recharge/Coefficient of Permeability)

Mass Flux Entering Element

LaTeX Go Mass Flux Entering the Element = Water Density*Gross Velocity of Groundwater*Head*Change in 'y' Direction

Change in Drawdown given Discharge Formula

LaTeX Go

Change in Drawdown = Discharge*ln(Radial Distance at Observation Well 2/Radial Distance at Observation Well 1)/2*pi*Transmissivity of an Unconfined Aquifer
s = Q*ln(r₂/r₁)/2*pi*T

What is Transmissivity?

Transmissivity describes the ability of the aquifer to transmit groundwater throughout its entire saturated thickness. Transmissivity is measured as the rate at which groundwater can flow through an aquifer section of unit width under a unit hydraulic gradient

How to Calculate Change in Drawdown given Discharge?

Change in Drawdown given Discharge calculator uses Change in Drawdown = Discharge*ln(Radial Distance at Observation Well 2/Radial Distance at Observation Well 1)/2*pi*Transmissivity of an Unconfined Aquifer to calculate the Change in Drawdown, The Change in Drawdown given Discharge formula is defined as the concept which quantifies how much the water level (drawdown) in an aquifer or well changes in response to a specific rate of water extraction (discharge). It is often used in the analysis of aquifer performance and is essential for sustainable groundwater management. Change in Drawdown is denoted by s symbol.

How to calculate Change in Drawdown given Discharge using this online calculator? To use this online calculator for Change in Drawdown given Discharge, enter Discharge (Q), Radial Distance at Observation Well 2 (r₂), Radial Distance at Observation Well 1 (r₁) & Transmissivity of an Unconfined Aquifer (T) and hit the calculate button. Here is how the Change in Drawdown given Discharge calculation can be explained with given input values -> 0.995048 = 1.3*ln(10/5)/2*pi*0.703.

FAQ

What is Change in Drawdown given Discharge?

The Change in Drawdown given Discharge formula is defined as the concept which quantifies how much the water level (drawdown) in an aquifer or well changes in response to a specific rate of water extraction (discharge). It is often used in the analysis of aquifer performance and is essential for sustainable groundwater management and is represented as s = Q*ln(r₂/r₁)/2*pi*T or Change in Drawdown = Discharge*ln(Radial Distance at Observation Well 2/Radial Distance at Observation Well 1)/2*pi*Transmissivity of an Unconfined Aquifer. The Discharge refers to the volumetric flow rate of water that is transported through a given cross-sectional area. It includes any suspended solids, dissolved chemicals, or biologic material, The Radial Distance at Observation Well 2 refers to the refers to the horizontal distance from the center of a pumping well to the observation well, The Radial Distance at Observation Well 1 refers to the refers to the horizontal distance from the center of a pumping well to the observation well & The Transmissivity of an Unconfined Aquifer refers to the ability of the aquifer to transmit groundwater throughout its entire saturated thickness.

How to calculate Change in Drawdown given Discharge?

The Change in Drawdown given Discharge formula is defined as the concept which quantifies how much the water level (drawdown) in an aquifer or well changes in response to a specific rate of water extraction (discharge). It is often used in the analysis of aquifer performance and is essential for sustainable groundwater management is calculated using Change in Drawdown = Discharge*ln(Radial Distance at Observation Well 2/Radial Distance at Observation Well 1)/2*pi*Transmissivity of an Unconfined Aquifer. To calculate Change in Drawdown given Discharge, you need Discharge (Q), Radial Distance at Observation Well 2 (r₂), Radial Distance at Observation Well 1 (r₁) & Transmissivity of an Unconfined Aquifer (T). With our tool, you need to enter the respective value for Discharge, Radial Distance at Observation Well 2, Radial Distance at Observation Well 1 & Transmissivity of an Unconfined Aquifer 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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