Lecture 3: Inventory and Analysis of the Biophysical Environment
Part III: Groundwater and Recharge Zones

Groundwater occurs when surface water seeps into the ground and it is either
• A) Taken up by the soils (Capillary action)
• B) is drawn to greater depths by GRAVITY

Groundwater
• Some water stays for a while, or for good in an AQUIFER
These might be made of
• Unconsolidated materials -- Soils, sands, gravel etc.
• Consolidated Materials -- cemented sandstone, cavernous limestone, even dense granite

Groundwater
The water from aquifers works its way back to the surface in different ways:
• Capillary action
• Underground rivers
• Springs
• Wells
•
Recharge Zones
• Once you have an aquifer, you have some water that leaves the aquifer that leaves, and some that replaces it
• That replacement water is called Recharge
It occurs in Recharge Zones:
• 1) Topographic depressions or wetlands
• 2) Highly permeable surface material - rock or soil
• 3) Exposed aquifer at surface


RECHARGE ZONES ARE A BIG DEAL

Old Axiom
DILUTION IS THE SOLUTION TO POLLUTION
Is it really???


Soils Still Matter
• Clay - high runoff
• Loam - moderate runoff
• Sand - Low runoff (Pine Barrens)



Coefficient of Runoff
• Different surfaces = different runoff
• What doesn't run off, can infiltrate

Forest c = 0.1 Residential and Agri = 0.5
Urban = 0.9