Permeability refers to how connected pore spaces are to one another. Permeability is another intrinsic property of all materials and is closely related to porosity. Note that some pores are isolated and cannot transport water trapped within them. Video showing how connected pores have high permeability and can transport water easily. We measure porosity by the percentage of empty space that exists within a particular porous media.įigure 3. The amount of water a material can hold is directly related to the porosity since water will try and fill the empty spaces in a material. However, in a material like a gravel, sand and clay mixture the porosity is much less as the smaller grains fill the spaces. In a material like gravel the grains are large and there is lots of empty space between them since they don’t fit together very well. In a soil or rock the porosity (empty space) exists between the grains of minerals. It refers to the amount of empty space within a given material. Porosity is an intrinsic property of every material.

Here are a few of the big ones and their meanings. There are lots of terms in hydrogeology, most of which are very simple, but essential. By squeezing that sponge we force the water out, similarly, by pumping an aquifer we force the water out of pore spaces. All of the holes in that sponge are water-filled. Generally speaking groundwater exists in the pore spaces between grains of soil and rocks. Many envision large underground lakes and rivers, and while those do exist, they represent an infinitesimally small percentage of all groundwater. However, there are still lots of misconceptions about how people envision groundwater. Yes, that water is black! (Photo: Matt Herod)Īs we’ve learned, groundwater is simply water that exists underground.

A spring coming out of the shale near Red Creek.

How does water move through a sponge?