Groundwater types and their geological activity. How does groundwater form?

Among the land waters, the largest reserves are groundwater, the total reserves of which are 60 million km3. Groundwater can be in a liquid, solid, or vapor state. They are found in the soil and rocks ah top earth's crust.

The ability of rocks to pass water depends on the size and number of pores, voids, cracks.

In relation to water, all rocks are divided into three groups: permeable(permeable to water) waterproof(retain water) and soluble.

Soluble rocks - is potassium and table salt, gypsum, limestone. When groundwater dissolves them, large voids, caves, funnels, wells are formed at a depth (this phenomenon is called karst).

Permeable rocks can be divided into two categories: permeable in their entirety (uniformly permeable) and relatively permeable (semi-permeable). Examples of well-permeable rocks are pebbles, gravel, sand. Semi-permeable include fine-grained sand, peat, etc.

In addition, permeable rocks can be water-intensive and not water-intensive.

Non-moisture-intensive breeds - these are rocks that freely pass water without being saturated with it. These are, for example, sands, pebbles, etc.

Water-intensive - these are rocks that hold a certain amount of water (for example, one cubic meter peat holds over 500 liters of water).

To waterproof mountain rocks include clays, massive crystalline and sedimentary rocks. However, these rocks can be fractured and vivo become permeable.

Layers of impermeable rocks over which aquifers lie are called waterproof.

On impervious rocks, water seeping down is retained and fills the gaps between the particles of the overlying permeable rock, forming aquifer.

Layers of permeable rocks that contain water are called aquifers.

On plains composed of sedimentary rocks, permeable and impervious layers usually alternate.

Groundwater occurs in layers (Fig. 1). They can be divided into three horizons:

• upper horizon- this is fresh water lying at a depth of 25 to 350 m.
• Middle horizon - waters lying at a depth of 50 to 600 m. They are usually mineral, or salty.
• lower horizon- water, often buried, highly mineralized, represented by brines. Occurs at a depth of 400 to 3000 m.

Deep water horizons can be juvenile and (of igneous origin) or relict. The water of the lower horizons in most cases was formed during the formation of the sedimentary rocks enclosing them.

According to the conditions of occurrence, groundwater is divided into soil water, perched water, and saturation water - groundwater and interstratal water (Fig. 2).

Soil water and perched water

ground water fill part of the gaps between soil particles. They are essential for the normal life of plants.

Verkhovodka lies shallow, exists temporarily, is not abundant. In our climatic conditions, it appears in the spring after the snow melts, sometimes in the fall.

Rice. 1. Layers groundwater

Rice. 2. Types of waters according to conditions

ground water

ground water form an aquifer on the first water-resistant layer from the surface. The groundwater surface is called groundwater mirror. The distance from the groundwater table to the waterproof layer is called waterproof layer thickness.

Groundwater is fed by infiltrated precipitation, water from rivers, lakes, and reservoirs.

Due to the shallow occurrence from the surface, the groundwater level experiences significant fluctuations according to the seasons of the year: it either rises after precipitation or snow melts, or decreases during dry periods. In harsh winters ground water may freeze.

Since the depth of groundwater is determined primarily climatic conditions, in different natural areas she is different. So, in the tundra, the groundwater level practically coincides with the surface, and in semi-deserts it is at a depth of 60-100 m, and not everywhere, and these waters do not have sufficient pressure.

The degree of dissection of the relief of the territory has a great influence on the depth of groundwater. The stronger it is, the deeper the groundwater is.

Groundwater is highly susceptible to pollution.

Interstratal waters

Interstratal waters- underlying aquifers enclosed between two water-resistant layers. In contrast to the groundwater level, the level of interstratal waters is more constant and changes less over time. Interstratal waters are cleaner than groundwater.

A special group of groundwater is pressure interlayer waters. They completely fill the aquifer and are under pressure. All the waters enclosed in layers lying in concave tectonic structures have pressure.

Opened by wells and rising upward, they pour out to the surface or gush. That's the way it works artesian wells(Fig. 3).

Rice. 3. Artesian well

The chemical composition of groundwater varies and depends on the solubility of adjacent rocks. According to the chemical composition, fresh (up to 1 g of salts per 1 liter of water), slightly mineralized (up to 35 g of salts per 1 liter of water) and mineralized (up to 50 g of salts per 1 liter of water) underground waters are distinguished. At the same time, the upper horizons of groundwater are usually fresh or slightly mineralized, and the lower horizons can be highly mineralized. Mineral water in their composition they can be carbonic, alkaline, ferrous, etc. Many of them have medicinal value.

Groundwater temperature

By temperature, groundwater is divided into cold (up to +20 °C) and thermal (from +20 to +1000 °C). Thermal waters are usually different high content various salts, acids, metals, radioactive and rare earth elements.

The natural outlets of groundwater (usually groundwater) to the surface of the earth is called sources(springs, keys). They are usually formed in low places where the earth's surface is crossed by aquifers.

Springs are cold (with a water temperature not higher than 20 °C), warm (from 20 to 37 °C) and hot, or thermal (over 37 °C). Periodically gushing hot springs are called geysers. They are located in areas of recent or modern volcanism (Iceland, Kamchatka, New Zealand, Japan).

Significance and protection of groundwater

Underground waters are of great importance in nature: they are the most important source of food, swamps; dissolve various substances in rocks and transfer them; with their participation, karst and landslide landforms are formed; when close to the surface, they can cause swamping processes; supply plants with moisture and nutrients dissolved in them, etc. They are widely used by humans: they are sources of pure drinking water; are used to treat a number of human diseases; provide the production process with water resources; used to irrigate fields; a large number of various chemicals are obtained from thermal waters (iodine, Gauber's salt, boric acid, various metals); The thermal energy of groundwater can be used to heat buildings, greenhouses, generate electricity, etc.

To date, in many regions, the state of groundwater is assessed as critical and having a dangerous trend of further deterioration. Despite the fact that groundwater reserves are large, they are renewed extremely slowly, and this must be taken into account when spending them. Equally important is the protection of groundwater from pollution.

Groundwater (and not only surface, but also deep) following other elements environment experiencing pollution economic activity people: from enterprises of the mining industry, storage facilities for chemical waste and fertilizers, landfills, livestock complexes, settlements and others. Among the substances polluting groundwater, the following prevail: petroleum products, phenols, heavy metals(copper, zinc, lead, cadmium, nickel, mercury), sulfates, chlorides, nitrogen compounds. Areas of hotspots of groundwater pollution reach hundreds of square kilometers. The quality of drinking water is deteriorating.

(up to a depth of 12-16 km) in liquid, solid and vapor states. The bulk of them is formed due to seepage from the surface of rain, melt and river waters. Groundwater is constantly moving both vertically and horizontally. Their depth, direction and intensity of movement depend on the water permeability of the rocks. Permeable rocks include pebbles, sands, gravel. To waterproof (waterproof), practically impervious to water - clays, dense without cracks, frozen soils. The layer of rock that contains water is called an aquifer.

According to the conditions of occurrence, groundwater is divided into three types: located in the uppermost, soil layer; lying on the first permanent water-resistant layer from the surface; interstratal, located between two water-resistant layers. Groundwater is fed by infiltrated sediments, waters, lakes,. The groundwater level fluctuates with the seasons of the year and is different in different zones. So, in it practically coincides with the surface, is located at a depth of 60-100 m. They are distributed almost everywhere, do not have pressure, move slowly (in coarse-grained sands, for example, at a speed of 1.5-2.0 m per day). The chemical composition of groundwater varies and depends on the solubility of adjacent rocks. According to the chemical composition, fresh (up to 1 g of salts per 1 liter of water) and mineralized (up to 50 g of salts per 1 liter of water) groundwater are distinguished. The natural outlets of groundwater to the earth's surface are called sources (springs, springs). They usually form in low places where aquifers cross the earth's surface. Springs are cold (with no higher than 20 ° C, warm (from 20 to 37 ° C) and hot, or thermal (over 37 ° C). Periodically spouting hot springs are called geysers. They are located in areas of recent or modern (,). The waters of the springs contain a variety of chemical elements and can be carbonic, alkaline, hydrochloric, etc. Many of them have medicinal value.

Groundwater replenishes wells, rivers, lakes,; dissolve various substances in rocks and transfer them; cause landslides. They provide plants with moisture and population drinking water. Springs provide the purest water. water vapor and hot water Geysers are used to heat buildings, greenhouses and power plants.

Groundwater reserves are very large - 1.7%, but they are renewed extremely slowly, and this must be taken into account when spending them. Equally important is the protection of groundwater from pollution.

The groundwater- waters located in the thickness of the earth's crust. They are located in different physical condition- liquid, solid (ice, as well as water bound in the crystal lattice of various minerals) and gaseous (water vapor). Most of the work is done by liquid water. But water inside the earth's crust is capable of moving from one state to another. Therefore, when studying the hydrological regime of groundwater, it is necessary to take into account all possible states of its location. The study of groundwater and its activities is the subject of a special discipline located at the intersection of geological and geographical sciences - hydrogeology .

Groundwater participates in the general water cycle, but with varying intensity. Allocate zones:

Free water exchange (upper) - for the most part fresh;

Slow water exchange (average) - mineralized;

Very slow water exchange (lower) - mainly brines.

Types of groundwater:

3. Film water envelops mineral particles with a film with a thickness of fractions of a micron. It is held by surface tension forces and can flow to where the film is thinner.

4. Hygroscopic water envelops mineral particles with a film, one molecule thick. It becomes mobile only upon transition to a gaseous form. Does not freeze at temperatures existing on Earth.

5. Ice- frozen water. May be in the form of small crystalline particles(in frozen soils) and form clusters.

6. gaseous water, or water vapor is contained in the composition of underground atmospheres.

7. Crystallization water is a part of minerals in the form of molecules (gypsum, opal). It is removed and goes into other states during dehydration reactions.

8. constitutional water- in the composition crystal lattice minerals in dissociated form. It is released only with the complete destruction of minerals during metamorphic processes.

Verkhovodka - temporary accumulation of gravitational groundwater in the aeration zone in rocks (soils) underlain by lenses or wedged out interlayers of waterproof (or poorly permeable) rocks. Verkhovodka is formed as a result of the penetration of atmospheric or surface water(melted snow or flood), as well as from artificial reservoirs; disappears due to intrasoil evaporation, seepage through poorly permeable soils or penetration to a permanently existing groundwater level.

Verkhovodka is characterized by seasonal variability, limited area distribution, sharp fluctuations in the level, reserves and chemical composition of waters. Verkhovodka, as a rule, is unsuitable for water supply. When conducting open-pit mining in the development of perched water, it is necessary to ensure the stability of the slopes of the entry, cut trenches and working sides, which is achieved by the use of surcharges, the construction of horizontal drainage wells, the use of drainage and drainage.

ground water - gravitational underground waters of the first permanent aquifer from the Earth's surface. They are formed mainly due to infiltration (leakage) of precipitation and water from rivers, lakes, reservoirs, irrigation canals and mines. drainage ditches. Groundwater surface - free, non-pressure; when groundwater is opened by wells or wells, their level is set at the depth where they were met. The areas of supply and distribution of groundwater coincide.

Depending on the amount of atmospheric precipitation, the surface of groundwater experiences seasonal fluctuations (in the dry season it decreases, in the wet season it rises), the flow rate also changes, chemical composition and groundwater temperature. Near rivers and reservoirs, changes in the level, discharge, and chemical composition of groundwater are determined by the nature of their hydraulic connection with surface water and the regime of the latter. The amount of groundwater runoff over a long period is approximately equal to the amount of water received by infiltration.

Groundwater is of great importance for the national economy as a source of water supply. industrial enterprises, settlements, etc. In the operation of groundwater, tasks are set rational use and protection of waters from depletion and pollution, which are observed in areas where industrial enterprises operate. The change in the chemical composition of groundwater is especially noticeable near chemical plants, thermal power plants, processing plants, rock dumps, irrigation canals, mine drainage ditches. In mining areas, there is also a violation of the natural hydrogeological regime and the depletion of groundwater resources (complete - with open method development and partial - at underground).

The degree of influence of underground mining operations on the regime and resources of groundwater depends on the ratio of the depth of development and the height of the development of water-conducting cracks in the zone above the mining workings during the extraction of minerals with the collapse of roof rocks. Preservation of groundwater regimes can be achieved by backfilling (full or partial) goaf (in this case, the height of development of the zone of water-conducting cracks should not exceed the base of the water-resistant layer of groundwater), as well as by plugging rock deformation zones, changing mining technology (for example, use of non-pillar extraction of minerals), rock pressure control, etc.

artesian waters - pressure reservoir water occurring between impervious layers. They form large water-pressure systems - artesian basins.

Artesian waters, uncovered by boreholes, rise above the roof of the aquifer, and with excessive hydrostatic pressure, they pour out onto the Earth's surface or gush. The formation of artesian water pressure is associated with the hydraulic isolation of aquifers, with the difference in the heights of the areas of supply and distribution of waters located in low areas; a certain role is also played by the squeezing of water from compacted sediments (clays) into less compacted sediments (sandstones, limestones). The conditions for the occurrence of artesian waters are varied - they are mainly confined to trough-shaped structures; are also found in the flexure-like asymmetric monoclinal occurrence of layers.

Artesian waters in areas of active water exchange are fresh or brackish, in stagnant conditions they are saline or brine and are, apparently, buried waters of ancient sea basins located in different geological epochs in this territory. During the development of deposits, artesian waters (if they are not an independent object of exploitation) appear in the form of breakthroughs, make it difficult to drive mine workings and require the use of special measures to protect the workings from water.

Fissure and karst waters - groundwater occurring and circulating in fractured and karst rocks. Fissure-karst waters are characterized by turbulent movement and relatively large water resources. When driving and extracting minerals without the use of water protection, fissure-karst waters manifest themselves in the form of increased water inflows and powerful sudden breakthroughs (often causing flooding of workings). Mining in the area of ​​fissure-karst waters also causes the development of a depression surface of groundwater on large area and exhaustion water resources. Fissure-karst waters, due to the increased water loss and good drainage of karst and fissured massifs containing water, are widely used in national economy for drinking and technical water supply.

Hydroisohypses, filtration coefficient

HYDROISOGIPS - lines connecting on a map (plan) points with the same absolute or relative elevations of the surface of free-flowing groundwater.

The filtration coefficient k is the most important hydrogeological characteristic of the rock containing the aquifer. Therefore, in any hydrogeological survey of the site, the filtration coefficient of aquifers must be determined by one method or another.

The filtration coefficient is determined as the arithmetic mean of the results of laboratory and field studies obtained under the same conditions.

The filtration coefficient depends on the properties of the rock and the fluid, so it is usually used for hydraulic engineering calculations in cases where the fluid is the same - water.

Water is the source of life on Earth, without it it is difficult to imagine activity modern man. Water is used for various purposes: drinking and household needs, watering livestock. Those who live in the private sector far from the city know that the main sources of drinking water are wells, wells or dams. In one case or another, it is necessary to conduct water on your own. Great importance has a definition of the exact location of the aquifer. The location of aquifers varies in depth, and the quality of water largely depends on this.

Each level of the aquifer has its own characteristics. Depending on this, several types of underground veins are distinguished: perched water, groundwater and interstratal water. The latter are divided into pressure and non-pressure. They are the cleanest, but at the same time, they are the most difficult to reach. Hydrogeological features are important not only in the construction of water supply, but also in the construction business. At the same time, the level of standing groundwater is of great importance. Let us consider in more detail how the perch, groundwater and interstratal waters differ from each other, what is their depth of occurrence.

Aquifers of the earth

In the thickness of the earth there are several aquifers. Water accumulates in the ground due to the presence of water-resistant layers. The latter are formed, to a greater extent, by clay. Clay practically does not let water through, thereby protecting aquifers from pollution. Less often, stones can be found in the water-resistant layer. An interesting fact is that between the clay layers there are almost always layers formed by sand. It is known that sand retains moisture (water), as a result of which water accumulates and thereby forms the aquifers of the earth. It is necessary to know that aquifers can be protected by aquifers on both sides or only on one side.

The deepest aquifer that is used in modern time for water consumption, formed by artesian waters. It can be located at a depth of more than 100 meters. Artesian waters do not lie in the thickness of the sand, but in a layer formed by limestone. Because of this, they have a special chemical composition. There are also more accessible aquifers. These include the top. It is of great importance that it is not protected from above by a waterproof layer, therefore it is not suitable for drinking needs. Aquifers can be thin in some areas and very large in others. This is observed as a result of a fracture of water-resistant layers. Such areas have a large debit.

Verkhovodka and its features

The very first aquifer is called perch. Such water got its name due to the fact that the layer is located very close to the surface. The depth at which it can be detected is from 1 to 4 meters. Verkhovodka refers to non-pressure groundwater. Such water is not everywhere, therefore it is a non-permanent aquifer. Verkhovodka is formed as a result of filtering surface water or precipitation through the soil. Because of this, she did not find wide application for drinking purposes. There are several reasons for this:

• low flow rate and its volatility;
• Availability a large number contaminants;
• inability to fully meet the needs of the population.

Verkhovodka is formed periodically. It depends on the presence of precipitation, floods. In the warm season (summer) it is very difficult to find this source of water. Often it is located on the first water-resistant layer, therefore, when this layer emerges, a wetland may form. The water of this aquifer is characterized by the fact that it is fresh and has low salinity. Plus it's dirty. organic matter. In some cases, it contains a lot of iron. It can be suitable for household needs as an additional source of water for watering or irrigating plants.

Groundwater characteristics

Determining the level of standing groundwater in private construction is observed very often. They are most often used for water supply of the residential sector. Wells or dams are built to collect groundwater. Wells are more often drilled for interstratal waters. Groundwater forms the first permanent aquifer, which lies on the first impervious layer of the earth. They are pressureless. This indicates that they are not protected from above by water-resistant rocks of the soil, while the earth layer itself remains half-filled.

They are distributed almost everywhere, in contrast to perched water. It is important that groundwater is largely dependent on precipitation, so its debit may vary depending on the time of year. It is larger in spring and autumn than in summer and winter. The level of this layer repeats the configuration of the relief, so the thickness of this layer is different in different territories. The water that accumulates in the alluvial bowels is widely used for drinking. Groundwater occurs at levels ranging from a few meters to tens of meters. The chemical composition and mineralization are determined by the location of the layer. If there are surface sources nearby (rivers, lakes) with fresh water, then the underground layers can be used for drinking, washing and other purposes. But this requires their purification (boiling or filtering).

Interstratal aquifers

When choosing an aquifer for a future well or well, you need to know that interstratal waters are of better quality (cleaner) than groundwater.

Interstratal waters are characterized by the fact that they are surrounded from above and below by water-resistant layers.

The depth at which they can be found is from 10 meters or more. There are non-pressure and pressure interstratal waters. The first are not so widespread, they are very difficult to find. They are found in layered sediments, at the top of the geological section. According to their chemical composition, they are more balanced and pure, therefore they are used for water supply.

The most popular are pressure waters, called artesian. It is established that their chemical composition is constant. They are rich in various minerals. Such water can be drunk even without pre-treatment. This aquifer is protected from above and below. Their debit is always large, and it is constant. The depth of their location is about 100 meters or more. It is for obtaining artesian water that a well is drilled. Artesian waters are among the minerals of great value.

How does water quality depend on the depth of the aquifer?

In the location of aquifers, water quality is considered to improve as depth increases. It really is. During the private construction of wells or wells, the first water begins to appear already at a depth of 2-3 meters from the surface. This is the water of the first aquifer. It is contaminated with chemicals, organic matter that comes from the surface. Of great importance are wastewater, which easily penetrate into the first aquifer. When building a well, the optimal digging depth is 15-20 meters.

Groundwater and interstratal waters occur here. To find an artesian vein, you need to dig further. In this case, it is better to use drilling. Thus, the occurrence of aquifers is of great importance for the water supply of the population. Many regions are experiencing a shortage of clean water, which is the reason for the search for new sources.

A considerable part of the Earth's water reserves are underground basins that flow in the soil and rock layers. Huge accumulations of groundwater are lakes that wash out rock deposits and soil, forming pits.

The value of ground fluid is great not only for nature, but also for humans. Therefore, researchers conduct regular hydrological observations of its condition and quantity, and study deeper and deeper what underground water is. Definition, classification and other issues of the topic will be discussed in the article.

What is underground water?

Groundwater is water located in the interlayer spaces of rocks occurring in top layer earth's crust. Such water can be presented in any state of aggregation: liquid, solid and gaseous. Most often, groundwater is tons of flowing liquid. The second most common are blocks of glaciers that have been preserved since the permafrost period.

Classification

The division of groundwater into classes depends on the conditions of their occurrence:

• soil;
• ground;
• interstratal;
• mineral;
• artesian.

In addition to the listed types, groundwater is divided into classes depending on the level of the layer in which they are located:

• The upper horizon is fresh groundwater. As a rule, their depth is small: from 25 to 350 m.
• The middle horizon is the location of a mineral or saline liquid at a depth of 50 to 600 meters.
• The lower horizon is a depth of 400 to 3000 meters. Water with high mineral content.

Groundwater, located at great depths, may be young in age, that is, recently appeared, or relict. The latter could be laid in the underground layers together with the ground rocks in which it is "placed". Or, relic underground water was formed from permafrost: the glaciers melted - the liquid accumulated and persisted.

ground water

Soil water is a liquid that occurs in the upper layer of the earth's crust. It is mainly localized in spatial voids between soil particles.

If you understand what soil-type groundwater is, it becomes obvious that this type of liquid is the most useful, since its surface location does not deprive it of all minerals and chemical elements. Such water is one of the main sources of "nutrition" for agricultural fields, forests and other crops.

This kind of liquid can not always lie horizontally, often its outlines are similar to the soil topography. In the upper layer of the earth's crust, moisture does not have a "solid support", so it is in a suspended state.

An excess amount of soil water is observed in the spring, when the snow melts.

ground water

The ground variety is the waters that are located at some depths of the upper earth layer. The depths of fluid flow can be large if it is an arid area or desert. At temperate climate with periodic constancy of precipitation, groundwater is not so deep. And with an excess of rain or snow, ground fluid can lead to flooding of the area. In some places, this kind of water comes to the surface of the soil and is called a spring, key or source.

Groundwater is replenished due to precipitation. Many confuse it with artesian, but the latter lies deeper.

Excess fluid can accumulate in one place. As a result of a standing position, swamps, lakes, etc. are formed from groundwater.

Interstratal

What is interlayer groundwater? These are, in fact, the same aquifers as ground and soil, but only the level of their flow is deeper than that of the previous two.

A positive feature of interstitial fluids is that they are much cleaner because they lie deeper. In addition, their composition and quantity always fluctuate within one constant limit, and if changes occur, then they are insignificant.

Artesian

Artesian waters are located at depths exceeding 100 meters and reaching 1 km. This variety is considered, and indeed is, the most suitable for human consumption. Therefore, on suburban areas drilling is often practiced underground wells as a source of water supply for residential buildings.

When drilling a well, artesian water bursts to the surface as a fountain, since it is a pressure type of groundwater. It lies in the voids of rocks between water-resistant layers of the earth's crust.

The reference point for the extraction of artesian water are certain natural objects located on the surface: depressions, flexures, troughs.

mineral

Minerals - the deepest and most healing and valuable for human health. They have an increased content of various mineral elements, the concentration of which is constant.

Mineral waters also have their own classifications:

By appointment:

• canteen;
• medical;
• mixed.

According to the predominance of chemical elements:

• hydrogen sulfide;
• carbonic;
• glandular;
• iodine;
• bromine.

According to the degree of mineralization: from fresh to waters with the highest concentration.

Classification by purpose

Groundwater is used in human life. Their purpose is different:

• drinking water is water that is suitable for consumption either in its natural, untouched form, or after purification;
• technical is a liquid that is used in various technological, economic or industrial sectors.

Classification by chemical composition

The chemical composition of groundwater is influenced by those rocks that are adjacent to moisture in close proximity. The following categories are distinguished:

1. Fresh.
2. Weakly mineralized.
3. Mineralized.

As a rule, the waters lying in close proximity to the earth's surface are freshwater. And the deeper the moisture is located, the more mineralized its composition.

How was groundwater formed?

Several factors influence the formation of groundwater.

1. Precipitation. Precipitation in the form of rain or snow is absorbed by the soil in the amount of 20% of the total. They form soil or ground fluid. In addition, these two categories of moisture are involved in the water cycle in nature.
2. Melting permafrost glaciers. Underground waters form whole lakes.
3. There are also juvenile fluids that were formed in solidified magma. This is a kind of primary water.

Groundwater monitoring

Groundwater monitoring is an important necessity, which allows you to track not only its quality, but also its quantity, and in general, its presence.

If the quality of water is examined in the laboratory, surveying the seized sample, then the exploration of the presence implies following methods, interconnected with each other:

1. The first is an assessment of the area for the presence of expected groundwater.
2. The second is the measurement of the temperature indicators of the detected liquid.
3. Next, the radon method is applied.
4. After that, basic wells are drilled, followed by core extraction.
5. The selected core is sent for research: its age, thickness and composition are determined.
6. A certain amount of groundwater is pumped out of the wells to determine their characteristics.
7. Based on the base wells, maps of the occurrence of the liquid are compiled, its quality and condition are assessed.

Groundwater exploration is divided into the following types:

1. Preliminary.
2. Detailed.
3. Operational.

Pollution problems

The problem of groundwater pollution is very relevant today. Scientists identify the following ways of pollution:

1. Chemical. This type of pollution is very common. Its globality depends on what is on Earth great amount agricultural and industrial enterprises that discharge their waste in liquid and solid (crystallized) form. These wastes penetrate very quickly into aquifers.
2. Biological. Polluted sewage from domestic use, faulty sewers - all these are the reasons for the contamination of groundwater with pathogens.

Classification by type of water-saturated soils

The following are distinguished:

• porous, that is, those that settled in the sands;
• cracked, those that fill the cavities of blocks of rocks and rocks;
• karst, those that are located in limestone rocks or other fragile rocks.

Depending on the location, the composition of the waters is also formed.

Stocks

Groundwater is regarded as a mineral that is renewable and participates in the water cycle in nature. The total reserves of this variety of minerals are 60 million km 3. But, despite the fact that the indicators are not small, groundwater is subject to pollution, and this significantly affects the quality of the consumed liquid.

Conclusion

Rivers, lakes, underground waters, glaciers, swamps, seas, oceans - all these are the water reserves of the Earth, which are somehow interconnected. Moisture located in the soil layers not only forms an underground pool, but also affects the formation of surface water bodies.

Groundwater is suitable for human drinking, therefore saving it from pollution is one of the main tasks of mankind.