Suction is the flow of a fluid into a partial vacuum, or region of low pressure. The pressure gradient between this region and the ambient pressure will propel matter toward the low pressure area. Suction is popularly thought of as an attractive effect, which is incorrect since vacuums do not innately attract matter.
Begrijp ik; wat ik me afvraag is hoe zo'n partiële vacuümruimtes ontstaan in een bodem: ik zou veronderstellen dat een continue interactie tussen oppervlakte en bodem ervoor zou zorgen dat de druk in evenwicht komt.
The unsaturated zone occurs between the water table and the ground surface. The pore water
pressure in that zone is usually lower than the atmospheric pressure. Water is in a state of suction or
negative pressure. Because of this suction, water is drawn up above the water table into interstices
and pores and creates the capillary fringe. The unsaturated zone is in constant interaction with the
atmosphere through infiltration, evaporation or plant transpiration.
Hoe wordt deze negative pressure dus gehandhaafd?
