Permeability (earth sciences)

Permeability in fluid mechanics and the earth sciences (commonly symbolized as κ, or k) is a measure of the ability of a porous material (often, a rock or an unconsolidated material) to allow fluids to pass through it.

The permeability of a medium is related to the porosity, but also to the shapes of the pores in the medium and their level of connectedness.


Permeability is the property of rocks that is an indication of the ability for fluids (gas or liquid) to flow through rocks. High permeability will allow fluids to move rapidly through rocks. Permeability is affected by the pressure in a rock. The unit of measure is called the darcy, named after Henry Darcy (1803-1858). Sandstones may vary in permeability from less than one to over 50,000 millidarcys (md). Permeabilities are more commonly in the range of tens to hundreds of millidarcies. A rock with 25% porosity and a permeability of 1 md will not yield a significant flow of water. Such “tight” rocks are usually artificially stimulated (fractured or acidized) to create permeability and yield a flow.

Latest News for: Soil permeability


There’s a secret wildlife wonderland hidden in the US — and it’s in danger

Vox 18 Jun 2024
On a muggy afternoon in May, JJ Apodaca stared intently at a very large rock. Apodaca, a biologist with a salt-and-pepper faux-hawk, was looking for a creature that, to an untrained eye, might be impossible to find ... Apodaca had an advantage in his search ... Spoiler ... Their skin is permeable, so they’re more exposed to pollution in the soil and water ... ....

Treatment of rock wool blocks for planting tomatoes in glass greenhouses

GetNews 17 Jun 2024
The substrate blocks for soilless cultivation of tomatoes in glass greenhouses are mostly made of rock wool or coconut strips. The substrate has good soilless water absorption and air permeability, which can isolate soil-borne diseases. Today, let's share how the substrate strips are foamed before planting. 1 ... 2 ... 3 ... 4 ... Media Contact. Company Name ... Email....

Sindh CS tells DCs to prepare flood contingency plans

The News International 08 Jun 2024
Sindh Chief Secretary Syed Asif Hyder Shah. — Facebook/Asif Hyder Shah. KARACHI ... However, spells in August are likely to be calm, connected, consecutive and long duration therefore, more dangerous because natural depressions, drainage system and soil permeability likely to be saturated with earlier spells held during June and July. ....

Summer flood claims becoming more commonplace, says major insurer

AOL 06 Jun 2024
The insurer cautioned that impermeable surfaces and a lack of soil and natural planting make it more difficult for water to soak away, which can overwhelm drains and cause flooding ... Using permeable materials that allow rainwater to soak through to the soil below – can help reduce the risk from surface water flooding....