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