Groundwater Notes PDF

Groundwater Notes  Groundwater 1 Evaporation seawater cycles water into the atmosphere in the form of invisible water vapor 2 2 Precipitation 1 Brings atmospheric moi...

Groundwater Notes  Groundwater 1 Evaporation seawater cycles water into the atmosphere in the form of invisible water vapor 2 2 Precipitation 1 Brings atmospheric moisture back to Earth’s surface. 3 Infiltration 3 process by which precipitation that has fallen on land moves into the ground and becomes groundwater  Groundwater Storage The zone of saturation is the region below Earth’s surface in which groundwater completely fills all the pores of a material. The water table is the upper boundary of the zone of saturation. The depth of the water table often varies depending on local conditions and precipitation. Therefore, the water table fluctuates with seasonal and other weather conditions. In the zone of aeration above the water table, materials are moist. However, they are not saturated with water so air occupies much of the pores.  Groundwater Movement The ability of a material to let water pass through it is its permeability. An aquifer is a layer of permeable subsurface material that is saturated with water. Aquicludes are impermeable layers and act as barriers to groundwater flow.  Springs Springs are the place where groundwater is released when an aquifer and an aquiclude are in contact. Springs can emerge from sides of valleys, at the edges of perched water tables, along faults, and from underground pathways. Hot springs release water that is much warmer than the average annual temperature.  Springs Geysers are EXPLOSIVE hot springs in which water is heated past its boiling point, causing it to vaporize. The resulting water vapor builds up tremendous pressure, which fuels eruptions at the surface.  Wells Wells are holes dug or drilled into the ground to reach an aquifer. 1. Water-table well are the simplest wells, which are dug or drilled below the water table. In a water-table well, the level of the water in the well is the same as the level of the surrounding water-table. As water is drawn out of a well, it is replaced by surrounding water in the aquifer. 2. Artesian well is a fountain formed from the pressurized water in a well drilled into a confined aquifer. Wells  Protecting our water supply Pollution can enter groundwater resources via runoff and infiltration, or directly from underground. Sometimes, polluted groundwater can be pumped out for chemical treatment on the surface. Humans must be aware of how their activities impact the groundwater system so that they can protect the water supply.  Groundwater Erosion Most groundwater is slightly acidic due to carbonic acid. This can cause limestone to dissolve over time A cave is a natural underground opening with a connection to Earth’s surface As groundwater infiltrates the ground, it gradually dissolves the adjacent rock and enlarges these passages to form an interconnected network of openings. A sinkhole is a depression in the ground caused by the collapse of a cave.  Groundwater Deposition Dripstones are rock formations that are built over time as water drips through caves. A form of dripstone, called a stalactite, hangs from the cave’s ceiling like icicles and forms gradually. As the water drips to the floor of the cave, it may also slowly build mound-shaped dripstones called stalagmites.