Geometry of the Water Table Similar in shape

Geometry of the Water Table Similar in shape to land surface, but more subdued Groundwater flows down slope of water table

Slope of the Water Table Influences Groundwater Flow Steeper slope = faster flow Faster Slower Groundwater divide

Types of Aquifers Unconfined aquifer open to Earth’s surface and to infiltration Perched aquifer underlain by lowpermeability unit Confined aquifer overlain by less permeable materials Artesian aquifer: water rises in pipe (maybe to surface)

Groundwater in Fractures can contain groundwater May be the only pathways for water, if interconnected More fractures = more water 17. 03. a 2

Bedrock Aquifer (Cunningham & Daniel, 2001)

Bedrock Aquifer http: //www. usgs. gov/envirohealth/geohealth/v 09_n 03/ - Arsenic and Other Natural Contaminants in New England Drinking Water Wells

Limestone (Karst) Aquifers Limestone is soluble Groundwater is slightly acidic Above water table, cave may be dry Below water table water further dissolves NOTmaterial where most groundwater occurs

Generalized geology of NC Aquifers of eastern NC http: //nc. water. usgs. gov/reports/ofr 041025/report. html

How Does Water Move Between the Surface and Subsurface? Water table intersects surface Why is there water in streams when it’s not raining?

How Are Lakes and Wetlands Related to Groundwater? Perched above water table Water table intersects surface Wetlands at water table or perched

How Do Streams Interact with Water Table? Stream lower than water table Stream higher than water table Gaining stream Losing stream

http: //pubs. usgs. gov/circ 1139/htdocs/natural_processes_of_ground. htm

http: //pubs. usgs. gov/circ 1139/htdocs/natural_processes_of_ground. htm