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
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) - Change in Drawdown in the Aquifer is a term applied to the maximum lowering of the groundwater table caused by pumping or artesian flow.
Discharge - (Measured in Cubic Meter per Second) - Discharge is 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) - Radial Distance at Observation Well 2 is the value of radial distance from well 2 when we have prior information of other parameters used.
Radial Distance at Observation Well 1 - (Measured in Meter) - Radial Distance at Observation Well 1 is the value of radial distance from well 1 when we have prior information of other parameters used.
Transmissivity - (Measured in Square Meter per Second) - Transmissivity is the rate at which groundwater flows horizontally through an aquifer or the degree to which a medium allows something, in particular electromagnetic radiation, to pass through it.
STEP 1: Convert Input(s) to Base Unit
Discharge: 3 Cubic Meter per Second --> 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: 11 Square Meter per Second --> 11 Square Meter per Second No Conversion Required
STEP 2: Evaluate Formula
Substituting Input Values in Formula
s = Q*ln(r2/r1)/2*pi*T --> 3*ln(10/5)/2*pi*11
Evaluating ... ...
s = 35.9301704900094
STEP 3: Convert Result to Output's Unit
35.9301704900094 Meter --> No Conversion Required
FINAL ANSWER
35.9301704900094 35.93017 Meter <-- Change in Drawdown
(Calculation completed in 00.004 seconds)

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Coorg Institute of Technology (CIT), Coorg
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10+ Unconfined Flow by Dupit's Assumption Calculators

Water table profile neglecting depths of water in drains
Go Water Table Profile = sqrt((Natural Recharge/Coefficient of Permeability)*(Length between tile drain-Flow in 'x' Direction)*Flow in 'x' Direction)
Change in Drawdown given Discharge
Go Change in Drawdown = Discharge*ln(Radial Distance at Observation Well 2/Radial Distance at Observation Well 1)/2*pi*Transmissivity
Natural Recharge given total head
Go Natural Recharge = (Water Table Profile^2*Coefficient of Permeability)/((Length between tile drain-Flow in 'x' Direction)*Flow in 'x' Direction)
Length about discharge per unit width of aquifer
Go Length between upstream and downstream = (Piezometric Head at Upstream End^2-Piezometric Head at Downstream End^2)*Coefficient of Permeability/(2*Discharge)
Discharge per unit width of aquifer is
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
Go Maximum Height of Water Table = (Length between tile drain/2)*sqrt(Natural Recharge/Coefficient of Permeability)
Length when Maximum Height of Water Table is Considered
Go Length between tile drain = 2*Maximum Height of Water Table/sqrt(Natural Recharge/Coefficient of Permeability)
Mass Flux Entering Element
Go Mass Flux Entering the element = Water Density*Gross Velocity of Groundwater*Head*Change in 'y' Direction
Recharge when Maximum Height of Water Table
Go Natural Recharge = (Maximum Height of Water Table/(Length between tile drain/2))^2*Coefficient of Permeability
Length when discharge entering per unit length of drain is considered
Go Length between tile drain = Discharge/Natural Recharge

Change in Drawdown given Discharge Formula

Change in Drawdown = Discharge*ln(Radial Distance at Observation Well 2/Radial Distance at Observation Well 1)/2*pi*Transmissivity
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 to calculate the Change in Drawdown, Change in Drawdown given Discharge is defined as Change in Drawdown in Aquifer is term applied to maximum lowering of groundwater table caused by pumping or artesian flow. 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 (T) and hit the calculate button. Here is how the Change in Drawdown given Discharge calculation can be explained with given input values -> 35.93017 = 3*ln(10/5)/2*pi*11.

FAQ

What is Change in Drawdown given Discharge?
Change in Drawdown given Discharge is defined as Change in Drawdown in Aquifer is term applied to maximum lowering of groundwater table caused by pumping or artesian flow 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. Discharge is 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 is the value of radial distance from well 2 when we have prior information of other parameters used, Radial Distance at Observation Well 1 is the value of radial distance from well 1 when we have prior information of other parameters used & Transmissivity is the rate at which groundwater flows horizontally through an aquifer or the degree to which a medium allows something, in particular electromagnetic radiation, to pass through it.
How to calculate Change in Drawdown given Discharge?
Change in Drawdown given Discharge is defined as Change in Drawdown in Aquifer is term applied to maximum lowering of groundwater table caused by pumping or artesian flow is calculated using Change in Drawdown = Discharge*ln(Radial Distance at Observation Well 2/Radial Distance at Observation Well 1)/2*pi*Transmissivity. 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 (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 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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