# Groundwater Hydraulics Daene C. McKinney

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Groundwater Hydraulics Daene C. McKinney
Flow in Aquifers Groundwater Hydraulics Daene C. McKinney

Summary Confined Aquifer Flow Unconfined Aquifer Flow
Continuity Equation Steady Horizontal Flow Transmissivity Unconfined Aquifer Flow Steady Horizontal Flow with Infiltration Drains

Unconfined Aquifer Flow

Flow in an Unconfined Aquifer
Dupuit approximations Slope of the water table is small Velocities are horizontal Ground surface Bedrock Unconfined aquifer Water table Dx Qx K h x y z

Steady Flow in an Unconfined Aquifer
1-D flow Steady State K = constant h Flow hA hB Water Table Ground Surface Bedrock L x

Steady Flow in an Unconfined Aquifer With Infiltration
hMax Flow hA hB Water Table Ground Surface Bedrock N, Infiltration L x Steady Flow Constant K

Steady Flow in an Unconfined Aquifer With Infiltration
hMax Flow hA hB Water Table Ground Surface Bedrock N, Infiltration L x

Steady flow in an unconfined aquifer with infiltration
hMax Flow hA hB Water Table Ground Surface Bedrock N, Infiltration L x

Example (Embankment) Given
h hMax Flow hA hB Water Table Ground Surface Bedrock N, Infiltration L x Given L = 3000 m K = 20 m/day hA = 30 m hB = 20 m N = 500 mm/yr Find: Flow to the streams and shape of water table

Example (Cont.) hMax h Flow hA hB L x N, Infiltration Ground Surface
Water Table Ground Surface Bedrock N, Infiltration L x

Example (Drains) Subsurface drains are often used to prevent the water table elevation from increasing to an elevation where it would waterlog the roots of crops or bring unwanted salts and other chemicals in to the root zone. Steady, 1-D flow , homogeneous, isotropic aquifer, w/infiltration hd hMax Water Table Ground Surface Lower Confining Layer N, Infiltration L x

Summary Confined Aquifer Flow Unconfined Aquifer Flow
Continuity Equation Steady Horizontal Flow Transmissivity Unconfined Aquifer Flow Steady Horizontal Flow with Infiltration Drains