GATE Overflow for GATE ESE - Recent questions in Groundwater Resources

GATE ES 2026 | Question: 47

Mon, 23 Feb 2026 13:14:28 +0000

A well penetrates an unconfined aquifer. The water level (i.e., head) in the well prior to pumping is $25$ $\mathrm{m}$. After a long period of pumping at a constant rate of $0.05 \mathrm{~m}^{3} / \mathrm{s}$, the drawdowns at distances of $50$ $\mathrm{m}$ and $150$ $\mathrm{m}$ from the well are observed to be $3$ $\mathrm{m}$ and $1.2$ $\mathrm{m}$, respectively.

The hydraulic conductivity of the unconfined aquifer is $\_\_\_\_$ $\times 10^{-4} \mathrm{~m} / \mathrm{s}$ (rounded off to two decimal places).

Consider $\pi=3.14$.

GATE ES 2025 | Question: 25

Thu, 06 Mar 2025 16:21:50 +0000

An unconfined aquifer of areal extent $20 \mathrm{~km} \times 20 \mathrm{~km}$ has hydraulic conductivity of $4 \mathrm{~m} / \mathrm{day}$, porosity of $0.32$, and storage coefficient (specific yield) of $0.18$. If the initial saturated thickness of the aquifer is $30 \: \mathrm{m}$ , and $4 \times 10^{8} \mathrm{~m}^{3}$ of water is extracted from the aquifer, then the decline in the saturated thickness is $\_\_\_\_\_\_$ m. (rounded off to two decimal places)

GATE ES 2025 | Question: 44

Thu, 06 Mar 2025 16:21:07 +0000

A homogeneous isotropic confined aquifer of uniform thickness $30 \: \mathrm{m}$ has hydraulic conductivity of $5 \mathrm{~m} / \mathrm{day}$ and porosity of $0.3$. There are two observation wells $\boldsymbol{X}$ and $\boldsymbol{Y}$ along a radial line from a fully penetrating pumping well at $100 \: \mathrm{m}$ and $200 \: \mathrm{m}$ distance, respectively. The well is pumped at a uniform rate to produce steady drawdown of $5 \: \mathrm{m}$ at $\boldsymbol{X}$ and $3 \: \mathrm{m}$ at $\boldsymbol{Y}$. If a non-reactive pollutant enters at the observation well $\boldsymbol{Y}$, then the time taken by the pollutant (under advection) to reach the observation well $\boldsymbol{X}$ is $\_\_\_\_\_\_$ days. (rounded off to two decimal places)

GATE ES 2024 | Question: 30

Mon, 19 Feb 2024 10:24:08 +0000

Consider two horizontal layers of an aquifer as shown in figure. Each layer is isotropic and homogeneous. Flow is parallel to the stratification. Thickness and horizontal hydraulic conductivity of layer-1 are $h_{1}$ and $K_{1}$, respectively. Thickness and horizontal hydraulic conductivity of layer-2 are $h_{2}$ and $K_{2}$, respectively, where $h_{1}$ is not equal to $h_{2}$. The equivalent horizontal conductivity $K_{x}$ for the aquifer system is given by ____________.

$K_{x}=\frac{K_{1} \cdot h_{1}+K_{2} \cdot h_{2}}{h_{1}+h_{2}}$
$K_{x}=\frac{K_{1}+K_{2}}{2}$
$K_{x}=\frac{K_{1} \cdot h_{2}+K_{2} \cdot h_{1}}{h_{1}+h_{2}}$
$K_{x}=\sqrt{K_{1} \cdot K_{2}}$

GATE ES 2023 | Question: 44

Tue, 23 May 2023 03:11:56 +0000

A fully penetrating well is installed in a homogenous and isotropic confined aquifer. The aquifer has uniform thickness of $16 \mathrm{~m}$ and hydraulic conductivity of $25 \mathrm{~m} / \mathrm{d}$. Water is being pumped out from the well at a constant rate of $0.1 \mathrm{~m}^3 / \mathrm{s}$ till steady state condition is reached. If a drawdown of $3.5 \mathrm{~m}$ is observed at a distance of $75 \mathrm{~m}$ from the well then the drawdown at a distance of $150 \mathrm{~m}$ from the well will be _____________ $\text{(in m, rounded off to two decimal places).}$

GATE ES 2021 | Question: 7

Tue, 14 Mar 2023 03:44:38 +0000

If $d$ is the depth of an aquifer through which water is flowing, then the relationship between permeability $K$ and transmissibility $\text{(also known as transmissivity)}$ $T$ is given by

$T=K d$
$T=K / d$
$T=\sqrt{K d}$
$K=\sqrt{T d}$

GATE ES 2021 | Question: 46

Tue, 14 Mar 2023 03:43:55 +0000

In a field test of a geological formation of permeable soil (porosity = $20 \%$ ), the hydraulic gradient was found to be $2 \%$. The actual seepage velocity of the flow was found to be $0.0025 \mathrm{~m} / \mathrm{s}$. Assume that the flow is in the laminar regime. The permeability $(K)$ of the aquifer is ____________ $\mathrm{m} / \mathrm{s}$ $\text{(rounded off to three decimal places)}$.

GATE ES 2022 | Question: 9

Fri, 17 Feb 2023 07:06:10 +0000

The correct order of hydraulic conductivity for the geologic formations is

Aquifer $>$ Aquitard $>$ Aquiclude $>$ Aquifuge
Aquifer $<$ Aquitard $<$ Aquiclude $<$ Aquifuge
Aquitard $>$ Aquifer $>$ Aquifuge $>$ Aquiclude
Aquifer $>$ Aquiclude $>$ Aquitard $>$ Aquifuge

GATE ES 2022 | Question: 47

Fri, 17 Feb 2023 07:05:38 +0000

Two reservoirs having a difference of $20 \mathrm{~m}$ in their water surface elevations are connected through a confined aquifer (thickness $=5 \mathrm{~m}$, length $=2 \mathrm{~km}$, hydraulic conductivity $K=3 \times 10^{-3} \mathrm{~m} / \mathrm{s}$, and porosity $\eta=0.3$ ) as shown in the following figure (drawn not to scale).

If the Reservoir 1 is contaminated by a pollutant then the time (in days, rounded off to one decimal place) taken by the pollutant to reach to the Reservoir 2 under advection will be