Final answer:
In anisotropic soils, horizontal hydraulic conductivity (k_x) and vertical hydraulic conductivity (k_z) can differ. Typically, k_x is greater than k_z in layered soils, but these values are related and not unrelated.
Step-by-step explanation:
The question pertains to anisotropic soils and how the hydraulic conductivity differs in horizontal (k_x) and vertical (k_z) directions. For anisotropic soils:
- a. (k_x = k_z) would suggest that the soil's hydraulic conductivity is the same in both horizontal and vertical directions, which is typically not the case for anisotropic soils.
- b. (k_x > k_z) indicates that the horizontal hydraulic conductivity is greater than the vertical, which is common in layered soils where water moves more easily along the layers.
- c. (k_x < k_z) suggests that the vertical hydraulic conductivity is greater than the horizontal, which is less common but can occur under certain soil conditions.
- d. (k_x) and (k_z) are unrelated, which is not accurate because in anisotropic soils, these values are related but not necessarily equal.
Understanding the relationship between k_x and k_z is essential for various engineering applications, such as groundwater flow modeling and the design of drainage systems.