§ 50. Groundwater (textbook)

§ 50. Underground water


Remember the water cycle in nature. What happens with water that gets on land as rain?


Water under the ground. A huge amount of water is in our feet - underground. It is almost 40 times more than in all the rivers, lakes and swamps of the world. Water that is in the top of the crust, called underground. In the subsoil water comes mainly from rainfall. Rain and thawed water seep in deep into the crust. There, they accumulate in the pores and crevices of rocks. Mountain breeds may skip or not skip the water. Depending on this distinguished permeable to water and water-proof (waterproof) layers of rocks.

Permeable to water rock capable hold water because they have a void - the pores and cracks. What larger particle species, the larger pores and the easier it is water. Good pass water, sand, gravel, pebbles, limestone with cracks. Thus, through the thick gravel for water infiltrates on day 100 m through the sand - 10 m by clay - 1 mm.

Waterproof rocklittle miss water. These are the clay, sandstone, granite, and if they do not cracks. Water that has leaked,  on such rocks of late. It fills the gaps between the particles of water-permeable rocks that lie above, piled up, forming aquifer.

Soil and mizhplastovi water. In the crust waterproof layers permeable to water and rocks alternate. Because aquifers are at various depths. Depending on the depth of their occurrence and distinguish soil mizhplastovi water.

Groundwater form upper aquifer, which lies on the ground from the surface waterproof layer. This fluid is blocked from the top waterproof layer, so filled up with water, that leaks from all over the surface that is above them. The level of groundwater water varies depending on the amount of water that leaked. Thus, the spring after melting snow, he rises at the end of the dry summer - is reduced. Change Groundwater level seen in wells of which are drinking water. If aquifer located under the slope, the ground water in it slowly (Eg, in the sands at speeds of 1-2 m per day) flowing towards the slope. In beams, ravines and river valleys they enter the Earth's surface and form source. Peculiar sources are hot source (thermal) And GeysersThat periodically emit water and steam on high.

Mizhplastovi water deposited in water-bearing layer, which lies between two waterproof layers. Water can get into this layer only where on it is not waterproof layer. So mizhplastoviwater replenished very slowly. If waterproof layers deposited chashopodibnoAnd aquifer between them filled water, then mizhplastovi water pressure and called pressure. If they drill wells, the water under pressure rises and strikes fountain. With the ability to climb well under pressure and gush mizhplastovi water is called artesian. The name comes from the province Artois in France, where in the XII century. dobuly them first.

Aquifer layers in one area may be few. They lie at various depths depending on climatic conditions: arid conditions in steppes and deserts - is much deeper than in a fairly damp climate.

Job groundwater. Groundwater, like surface, carry out some work in the earth's crust. Penetrating in rocks, water they can erode and dissolve. In soluble rocks, such as salt, gypsum, limestone having oral - cave. In Ukraine, they are common in Crimean mountains, on Tail. The largest cave in the world is Flint-Mammoth (USA) long, 361 km. In Ukraine, the largest cave is on the tail - Optimistic (201 km) Crimean mountains - Red (14 km).

Underground water plants provide moisture and dissolved nutrients in them. They are an important source of power of rivers and lakes.

The use of groundwater. For a man underground water - is real wealth. Such water prosochuyuchys in depth, passing through a series of natural filters - layers of rocks of different densities and thus perfectly cleared. Underground water is the purest, best drinking water. Therefore time immemorial, people extracted it, organizing wells. In Ukraine, drilled one thousand artesian wells to provide drinking water to urban population irrigation fields in areas poor in surface water.

Underground water containing high amount of dissolved salts and gases, called mineral. They used for therapeutic purposes. Near mineral springs are built sanatorium. Ukraine has many sources of mineral waters. At their base there Resorts Morshina, Maximus, Chmelnik Mirgoroda and other cities.

Thermal ground water with a temperature over 20 0C used for heating homes, greenhouses, to produce electricity. Hot water is widely used in Iceland Russia Japan and other countries.

Protection of groundwater. Underground water, like surface, are not inexhaustible. Now on Earth millions of wells drilled, through which will reach the groundwater. A refill them, particularly between formation occurs very slowly. Therefore, they should spend sparingly.

As and surface and underground water may be dirty. Contaminate their waste water Enterprise bridge that seep from the surface. Groundwater is contaminated and at entry to the soil mineral fertilizers. In mizhplastovi water can get oil from wells at its extraction. To keep groundwater clean, to clean waste water and strictly follow that contaminants do not end up underground.



Fig. Drinking water - from the ground


Questions and Tasks

1. Why do some rocks pass water, and others - not?

2. How different from the groundwater reservoir between?

3. If no source on the surface, does it mean that locally there groundwater?

4. What job in nature perform groundwater?

5. How people use groundwater? How they are used in your community?

6. How do you understand the phrase: "Where proberetsya, and that will be enough? As people ability to use such water?