lecture 4 ground water

• ground water

  is the water that exists in the voids of the geological stratum below the surface of the earth
• ground water

  is found in vast quantities filling the spaces between grains of soil or rocj and it slowly flows through aquifer
• meteoric water

  this refer to ground water which originate from rainfall and other forms of precipitation such as hailstorms and snow fall. it is the result of precipitation water seeping into the ground
• connate water (fossil water)

  this is water trapped in the pores of the rock during the formation of the rocks. the chemical composition of water changes that the rock undergoes.
• juvenile water (magmatic water)

  is water that exists within, and in equilibrium with, a magma or water-rich volatile fluids. this water is released to the atmosphere during a volcanic eruption
• three zones of distribution of groundwater

  • water table
  • unsaturated zone/vadose zone/aeration zone
  • saturated zone/phreatic water zone
• unsaturated zone

  region of subsurface from ground surface to the water table. pores are partially filled with water. unfilled pore space contains air.
• water table

  interface between unsaturated and saturated zone in unconfined aquifers
• saturated zone

  region of subsurface in which pore spaces are saturated (completely filled) with water
• aqua

  means water
• ferre

  means bear
• aquifer

  is an underground layer of water-bearing rock
• types of acquifers

  • unconfined
  • confined
• unconfined acquifers

  those into which water seeps from ground surface directly above the acquifer. covered by permeable rock and can receive water from the suface.
• confined acquifer

  water seeps from farther away where the impermeable layer doesnt exist
• artesian and flowing well

  is a confined acquifer containing groundwater under positive pressure. trapped water surrounded by layers of impermeable rocks or clay.
• porosity

  amount of spaces in-between sediments
• acquitard

  a bed of low permeability rock which containes no adjacent to an acquifer; interconnected opening may serve as a storage or interstices and unit for therefore neither absorbs groundwater, although it no transmits water. does not yield water readily
• aquiclude

  it is a solid, impermeable are underlying or overlying an acquifer.
• pumping of groundwater

  is the source of usable, freshwater in the world, but over pumping can cause different negative effects
• subsidence

  sinking of the ground because of underground material movement. most often caused by removal of water, oil, natural gas or mineral resources out of the ground by pumping, fracking or mining activities
• salt water intrusion

  a process in which occurs in most coastal acquifers. usually happens in the area near the sea