When groundwater flowlines cross a geological boundary between formations with different values of hydraulic conductivity, they refract, much as light does when it passes from one medium to another. Watch the video below and answer the questions that follow.
Questions:
1. What continuity conditions must be satisfied as groundwater flow across the interface? Or more specifically, which of the following must be continuous at the interface:
- specific discharge in x direction (along the interface),
- specific discharge in the y direction (normal to the interface),
- hydraulic gradient in x direction,
- hydraulic gradient in y direction.
- flow along a stream tube (between two streamlines)
2. Use these continuity conditions to derive the law of refraction in groundwater at the interface:
