Solution Exercise 9
In describing how a karst aquifer is fundamentally different from a clastic aquifer, the response should note that, compared to other aquifer types, karst aquifers generally have triple porosity and permeability fields (matrix, fractures, and conduits). Permeability can be highly anisotropic, very high, and range over many orders of magnitude. Recharge in karstic units commonly has both discrete and diffuse components. Discrete recharge through sinkholes and fractures is characteristic of many karst aquifers. Losing streams are common in karstic units. Clastic aquifers may be strongly controlled by variations in bedding facies.
In describing how a karst aquifer is fundamentally different from a crystalline rock aquifer, the response should indicate that crystalline rock aquifers tend to be shallow, have very low storativity, and their permeability is dominated by fracture sets.