Groundwater


Global distribution of water

Sea - 95.26, 97%, (96.7)

Freshwater 3% (3.3)

Freshwater

Ice/Glacier 75%

Ground water 24.6%

Rivers/Lakes 0.32%

Atmosphere 0.03%

Soil 0.05%

Approximately 1.385 billion cubic km of water in the world

Glacial/ice 2.1% 2.97

Ground water 0.6%1.05

Lakes/Rivers0.01% - 0.009

Atmosphere0.002% - 0.001

Biosphere 4 km 0-5%

Refer class to Hydrologic cycle


Importance of ground water

Porosity - % of rocks volume that is opening

Note relation between porosity and permeability

Permeability - capacity of the rock to transmit fluid


Types of water around sand grain - Hygroscopic, Capillary, Gravity

Unsaturated zone

(Perched H2O table)

Saturated zone (Aquifer)

Water table - form and shape

Flow

Groundwater could supply H2O to rivers (gaining rivers) Losing streams (more in drier climates)

Spring - where water flows naturally from rock into the land surface


Types of Aquifer -
1) Unconfined and
2) Confined

artesian conditions may exist in confined aquifers

Wells - Recharge, Cone of depression

drawdown

Pollution of Groundwater

Sources of gallon pollution

Pesticides/Herbicides

Fertilizers - nitrate

Heavy metals

Acid mine drainage (coal/metal mines)

Septic tanks, sewage plants, animal feedlots

(bacteria, viruses, parasites)

Some pollution could be natural.

Why should we protect ground or at least prevent ground water pollution in the first place?


Effects of Ground Water Action

Caves (or caverns) - underground chambers

Dripstones - Deposit of calcite formed by dripping water H2O

Stalactites (from roof) Stalagmite (from floor)

Column when the two are joined together

Sinkholes- form by cave roof collapsing or by solution. Sinkholes are also formed in the areas with gypsum or rock salt in addition to limestone.

Areas with sinkholes/caves -
Karst topography are areas that usually lack surface H2O

Preservation of fossils Plant

- Petrified wood - Silica

- Concretion - when a considerable amount of cementing material precipitates locally in a rock, a hard mass

Silica or Calcite - Geodes - partly hollow

Hot water underground

Hot Springs

Geyser

Geothermal Energy