Assertion: permeability | /r/CapableOf | decrease as their depth
Facets:
value: below land surface increases
type: OTHER
value: on the average
type: OTHER
Source sentences:
text: On the average, however, the porosity and permeability of rocks decrease as their depth below land surface increases; the pores and cracks in rocks at great depths are closed or greatly reduced in size because of the weight of overlying rocks.