Drawdown at Time Interval 't1' Calculator

✖Drawdown at time interval t2 is a term applied to the maximum lowering of the groundwater table.ⓘ Drawdown at time interval t2 [s₂]			+10% -10%
✖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.ⓘ Discharge [Q]			+10% -10%
✖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.ⓘ Transmissivity [T]			+10% -10%
✖Time of Drawdown (t2) is the total period for the difference between the pumping water level and the static (non-pumping) water level.ⓘ Time of Drawdown (t2) [t₂]			+10% -10%
✖Time of Drawdown (t1) is the total period for the difference between the pumping water level and the static (non-pumping) water level.ⓘ Time of Drawdown (t1) [t₁]			+10% -10%

✖Drawdown at time interval t1 is a term applied to the maximum lowering of the groundwater table.ⓘ Drawdown at Time Interval 't1' [s₁]

⎘ Copy

👎

Formula

✖

Drawdown at Time Interval 't1'

Formula

`"s"_{"1"} = "s"_{"2"}-(("Q"/(4*pi*"T"))*ln("t"_{"2"}/"t"_{"1"}))`

Example

`"15.05393m"="15m"-(("3.0m³/s"/(4*pi*"11m²/s"))*ln("10s"/"120s"))`

Calculator

LaTeX

Reset

👍

Download Engineering Hydrology Formula PDF PDF Image

Drawdown at Time Interval 't1' Solution

STEP 0: Pre-Calculation Summary

Formula Used

Drawdown at time interval t1 = Drawdown at time interval t2-((Discharge/(4*pi*Transmissivity))*ln(Time of Drawdown (t2)/Time of Drawdown (t1)))
s₁ = s₂-((Q/(4*pi*T))*ln(t₂/t₁))
This formula uses 1 Constants, 1 Functions, 6 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

Drawdown at time interval t1 - (Measured in Meter) - Drawdown at time interval t1 is a term applied to the maximum lowering of the groundwater table.
Drawdown at time interval t2 - (Measured in Meter) - Drawdown at time interval t2 is a term applied to the maximum lowering of the groundwater table.
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.
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.
Time of Drawdown (t2) - (Measured in Second) - Time of Drawdown (t2) is the total period for the difference between the pumping water level and the static (non-pumping) water level.
Time of Drawdown (t1) - (Measured in Second) - Time of Drawdown (t1) is the total period for the difference between the pumping water level and the static (non-pumping) water level.

STEP 1: Convert Input(s) to Base Unit

Drawdown at time interval t2: 15 Meter --> 15 Meter No Conversion Required
Discharge: 3 Cubic Meter per Second --> 3 Cubic Meter per Second No Conversion Required
Transmissivity: 11 Square Meter per Second --> 11 Square Meter per Second No Conversion Required
Time of Drawdown (t2): 10 Second --> 10 Second No Conversion Required
Time of Drawdown (t1): 120 Second --> 120 Second No Conversion Required

STEP 2: Evaluate Formula

Substituting Input Values in Formula

s₁ = s₂-((Q/(4*pi*T))*ln(t₂/t₁)) --> 15-((3/(4*pi*11))*ln(10/120))

Evaluating ... ...

s₁ = 15.0539297967867

STEP 3: Convert Result to Output's Unit

15.0539297967867 Meter --> No Conversion Required

FINAL ANSWER

15.0539297967867 ≈ 15.05393 Meter <-- Drawdown at time interval t1

(Calculation completed in 00.004 seconds)

You are here -

Home » Engineering » Civil » Engineering Hydrology » Groundwater Hydrology » Unsteady Flow in a Confined Aquifer » Drawdown at Time Interval 't1'

Credits

Created by Mithila Muthamma PA

Coorg Institute of Technology (CIT), Coorg

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

Verified by M Naveen

National Institute of Technology (NIT), Warangal

M Naveen has verified this Calculator and 900+ more calculators!

< 11 Unsteady Flow in a Confined Aquifer Calculators

Equation for Drawdown

Go Total Drawdown = (Discharge/(4*pi*Transmissivity))*ln((2.2*Transmissivity*Time Period)/(Distance from Pumping Well^2*Storage Coefficient))

Drawdown at Time Interval 't1'

Go Drawdown at time interval t1 = Drawdown at time interval t2-((Discharge/(4*pi*Transmissivity))*ln(Time of Drawdown (t2)/Time of Drawdown (t1)))

Drawdown at Time Interval 't2'

Go Drawdown at time interval t2 = ((Discharge/(4*pi*Transmissivity))*ln(Time of Drawdown (t2)/Time of Drawdown (t1)))+Drawdown at time interval t1

Equation for Well Function series to number of 4 digits

Go Well Function of u = -0.577216-ln(Well Parameter)+Well Parameter-(Well Parameter^2/2.2!)+(Well Parameter^3/3.3!)

Equation for Well Parameter

Go Well Parameter = (Distance from Pumping Well^2*Storage Coefficient)/(4*Transmissivity*Time Period)

Distance from Pumping Well given Storage Coefficient

Go Distance from Pumping Well = sqrt((2.25*Transmissivity*Starting Time/Storage Coefficient))

Initial Time given Pumping Well along with Storage Coefficient

Go Starting Time = (Storage Coefficient*Distance from Pumping Well^2)/(2.25*Transmissivity)

Transmissivity about given storage coefficient

Go Transmissivity = (Storage Coefficient*Distance from Pumping Well^2)/(2.25*Starting Time)

Equation for Storage Coefficient

Go Storage Coefficient = 2.25*Transmissivity*Starting Time/Distance from Pumping Well^2

Initial Constant Piezometric Head given drawdown

Go Initial constant Piezometric Head = Possible Drawdown in Confined Aquifer+Drawdown at time t

Drawdown given Piezometric Head

Go Possible Drawdown in Confined Aquifer = Initial constant Piezometric Head-Drawdown at time t

Drawdown at Time Interval 't1' Formula

Drawdown at time interval t1 = Drawdown at time interval t2-((Discharge/(4*pi*Transmissivity))*ln(Time of Drawdown (t2)/Time of Drawdown (t1)))
s₁ = s₂-((Q/(4*pi*T))*ln(t₂/t₁))

What is Drawdown in Hydrology?

Drawdown is a change in groundwater level due to an applied stress, caused by events such as: Pumping from a well. Pumping from a neighbouring well. Intensive water taking from local area. Seasonal declines as recharge rates lower.

How to Calculate Drawdown at Time Interval 't1'?

Drawdown at Time Interval 't1' calculator uses Drawdown at time interval t1 = Drawdown at time interval t2-((Discharge/(4*pi*Transmissivity))*ln(Time of Drawdown (t2)/Time of Drawdown (t1))) to calculate the Drawdown at time interval t1, The Drawdown at Time Interval 't1' is defined as a reduction in the pressure head surrounding the pumped well. Drawdown at time interval t1 is denoted by s₁ symbol.

How to calculate Drawdown at Time Interval 't1' using this online calculator? To use this online calculator for Drawdown at Time Interval 't1', enter Drawdown at time interval t2 (s₂), Discharge (Q), Transmissivity (T), Time of Drawdown (t2) (t₂) & Time of Drawdown (t1) (t₁) and hit the calculate button. Here is how the Drawdown at Time Interval 't1' calculation can be explained with given input values -> 15.05393 = 15-((3/(4*pi*11))*ln(10/120)).

FAQ

What is Drawdown at Time Interval 't1'?

The Drawdown at Time Interval 't1' is defined as a reduction in the pressure head surrounding the pumped well and is represented as s₁ = s₂-((Q/(4*pi*T))*ln(t₂/t₁)) or Drawdown at time interval t1 = Drawdown at time interval t2-((Discharge/(4*pi*Transmissivity))*ln(Time of Drawdown (t2)/Time of Drawdown (t1))). Drawdown at time interval t2 is a term applied to the maximum lowering of the groundwater table, 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, 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, Time of Drawdown (t2) is the total period for the difference between the pumping water level and the static (non-pumping) water level & Time of Drawdown (t1) is the total period for the difference between the pumping water level and the static (non-pumping) water level.

How to calculate Drawdown at Time Interval 't1'?

The Drawdown at Time Interval 't1' is defined as a reduction in the pressure head surrounding the pumped well is calculated using Drawdown at time interval t1 = Drawdown at time interval t2-((Discharge/(4*pi*Transmissivity))*ln(Time of Drawdown (t2)/Time of Drawdown (t1))). To calculate Drawdown at Time Interval 't1', you need Drawdown at time interval t2 (s₂), Discharge (Q), Transmissivity (T), Time of Drawdown (t2) (t₂) & Time of Drawdown (t1) (t₁). With our tool, you need to enter the respective value for Drawdown at time interval t2, Discharge, Transmissivity, Time of Drawdown (t2) & Time of Drawdown (t1) and hit the calculate button. You can also select the units (if any) for Input(s) and the Output as well.

Home

FREE PDFs

🔍 Search