this is where it all begins the Water Cycle this is where it all begins
water cannot pass through Infiltration (also called percolation) only happens when the ground is permeable Permeable Impermeable water can pass through water cannot pass through sedimentary rock sand & silt loam compost / humus igneous & metamorphic rock *bedrock layer clay asphalt / concrete
Groundwater water stored underground Zone of aeration Unsaturated zone Pore spaces in the material are filled mainly with air Zone of saturation (also called an Aquifer) Pore spaces in the material are filled with water Water within the pores is groundwater Water table --the upper limit of the zone of saturation water table can move up when it rains or down during a drought
Aquitard – an impermeable layer of material Aquifer – a permeable layer of material
unconfined confined Two Types of Aquifers type of aquifer description water rests on an impermeable layer; ground above it is permeable; can be refilled from rainwater that infiltrates water trapped between 2 impermeable layers; water becomes pressurized; cannot be refilled from rainwater infiltration type of well regular well (water needs to be drawn or pumped out) Artesian well (water rises under its own pressure)
Springs Spring groundwater that emerges naturally from the surface when the water table intersects with the surface of Earth
Porosity & Permeability Porosity – amount of water that can be stored in the pore spaces Permeability – ability of water to flow through connected pore spaces pore spaces are air !!!
Wells Well - hole drilled into the zone of saturation for extracting water Artesian Well – well drilled into a confined aquifer; rises under its own pressure
Cone of depression – lowering of the water table around a well due to large amounts of water being pumped out
Groundwater Overuse (cont’d) Ground subsidence (sinking) can occur if water is used faster than it is replenished Creates depressions or sinkholes
Sources of Groundwater Contamination Sewage from septic tanks, farm wastes, inadequate or broken sewers Fertilizers and pesticides from agriculture Residential runoff Highway salts Chemical and industrial materials that leak from pipelines, storage tanks, landfills, or holding tanks Saltwater in coastal areas Minerals and nutrients from dissolved rock and other natural materials
Types of Groundwater Pollution Point Source Pollution – contaminants have an identifiable source Smokestacks, car tailpipe Nonpoint Source Pollution – contaminant source cannot be found Several farmlands in the same area
Contaminant Spreading Flow downhill – contaminants leaked into the ground at the top of a hill will flow downhill Rainwater runoff – runs through the contaminant, absorbs it, and transfers it to another area
Groundwater Cleaning Infiltration/Percolation - if water travels slowly through permeable sediment, the water is purified
River Basins the land surface that drains surface water into one large river which takes the water to the ocean
River Basins (cont’d) Watersheds (river basins) separated from each other by areas of higher elevation (divides). Tributaries - small streams branching from larger streams and rivers
North Carolina’s River Basins There are 17 river basins in North Carolina Four of these river basins are found only in NC The Hiwassee, Little Tennessee, French Broad, Watauga, and New River Basins empty into the Mississippi River while all the others empty into the Atlantic Ocean.
Catawba River Basin In 2006, over 1.7 million people lived within the Catawba River Basin Includes 15.6% of North Carolina’s population Covers 6.24% of NC’s land 8th largest river basin in NC
Assignment River Basin Posters Include: Size of basin Miles of streams/rivers What part of NC Draw a plant or animal Describe a water quality issue Explain or propose a solution A unique geological or water feature Draw you and your partner doing one of the recreational activities
Wetlands Land that is covered by water all or part of the year. Includes swamps, marshes and bogs
Why Wetlands are Important Provide flood protection during storms Filter pollution & urban runoff Habitat for many animals
Types of Wetlands Swamp Mostly trees & bushes Marsh Tall grasses, some trees & bushes Carolina Bays Unique to East Coast Oval-shaped lakes that often fill with plants & sediment
Headwater Swamp January 2002
Swamp Forest January 2002
Wet Pine Flat Hard Wood Flat January 2002
Tidal Salt Marsh January 2002
Disappearing Wetlands Drained for development New homes, roads and schools Laws now prevent the destruction of wetlands Developers must create new wetlands if they destroy old ones “In nature there are no rewards or punishments, only consequences”