SOIL MOISTURE AND GROUNDERWATER RECHARGE Flashcards
three phase system
solid, liquid, gas
is the depression or the rise of a liquid in a small capillary passage tube having a small cross-sectional area such as openings in the porous materials.
Capillarity
is the subsurface layer in which groundwater seeps up from a water table by capillary action to fill pores.
The capillary fringe
Capillarity- results from 2 force: mutual attraction (_________) between water molecules and the molecular attraction (__________) between water and different soil materials
Cohesion
adhesion
can provide a means of direct evaporation of ground water if the water table is close enough to the surface
The capillary fringe
-measuring instrument used to determine water potential (soil moisture tension) in the vadose zone.
Tensiometer
- H20 in the vadose zone available to growing plants, found in belt of soil water
*
Soil water
Zone extends from land surface to depth of plant roots
*
Soil water
Top of capillary fringe may be below the belt of soil water.
- Intermediate zone (bet. BSW and CF)
Soil water
Soil moisture at a location varies with changes in the _______________ and ______________
amount of precipitation
evapotranspiration.
-when soil-moisture content of a layer reaches to the point at which the force of gravity acting on the water = the surface tension, gravity drainage cease.
Field capacity
the remaining moisture is too tightly bound to the soil particles
Wilting Point
