October 18, 2011
Objective :Determine the
porosity of soils and water flow with three different sized particles.
Agenda:Ground water notesLab: Porosity of soils
and water flow
runoff
HYDROLOGIC CYCLE
infiltration
aquifer Groundwater flow
transpiration
evaporation
precipitation
condensation
Water tableStream, spring, lake, or ocean
GROUND WATER
Groundwater is always moving --but very slowly
PERMEABILITY – ABILITY OF WATER TO FLOW (IMPERMEABLE – NO WATER CAN FLOW THROUGH)
POROSITY – PORE SPACES BETWEEN SEDIMENTS
CAPILLARITY – THE ABILITY OF WATER TO MOVE UPWARD IN SOIL
3 FACTORS AFFECT INFILTRATION
1.Permeability – larger size = BETTER small – impermeable (cannot flow through)
2.Porosity – size has NO EFFECTa. Shape – round = bestb. Packing – loosely packed or less
densec. Sorting – well sorted
3.Capillarity – smaller size sediment = BETTER
GRAVEL Rapid
drainage
FINE SANDModerate drainage
CLAYSlow
drainage
PERMEABILITY
Clay is impermeable – water will not flow through easily
SMALLER SIZED PARTICLES INCREASE CAPILLARITY
CAPILLARITY – WATER MOVES UPWARD
INFILTRATION
Infiltration refers to water soaking into the ground:
Infiltration rate
Slope
Infiltration rate
Permeability
Infiltration rate
Porosity
Infiltration rate
Soil Storage Saturation
GROUND WATER - Aquifer
1. WATER INFILTRATES 2. STOPS AT IMPERMEABLE
LAYER3. RISES FROM BOTTOM UP –
(LIKE FILLING A BATH TUB) THIS IS CALLED GROUNDWATER AKA – SATURATED ZONE AKA - AQUIFER
4. TOP OF SATURATED ZONE IS THE WATER TABLE
5. UNSATURATED ZONE – AIR AND WATER
6. CAPILLARY FRINGE – WATER RISES TO FEED ROOTS
WATER TABLE RISES WITH RAINFALLFALLS WITH DROUGHT