Hydrogeological maps of the survey site. Water and hydrogeology in the Moscow region
Hydrogeology - area of geology, where the origin is studied groundwater, their physico-chemical interaction with rocks, including the processes that cause the movement of water in them and the exchange of mineral matter with them. Water in rocks can be in a bound or mobile state.
The first of these, until a certain time, is held up to the surface or inside the crystals of minerals by the forces of intermolecular attraction. At the same time, the chemical composition of the pore water gradually changes due to oxidation-reduction, diffusion, radiation processes. Movable water moves in the intercrystalline space, so it has constant contact with the porous water, exchanging dissolved components with it.
Thus, the salt composition of the underground mobile waters is formed. As a rule, carbonate rocks (consisting of calcium carbonate and / or magnesium) and sodium and potassium chlorides are more soluble. Therefore, in general, the salt composition of groundwater is mainly determined by the ratio of the concentrations of these elements.
Nuclear reactions in water?
There is a hypothesis that a change in the salt composition of water can occur at the expense of nuclear reactions atoms of hydrogen and oxygen, constituting water molecules, when they interact with deeply penetrating cosmic particles. This hypothesis is confirmed by the fact that before the earthquakes, not only the gas composition of groundwaters changes (dissolved, hydrogen, helium, some other inert gases appear), but also the isotopic composition, in particular, dissolved uranium, changes.
The saturation of rocks with water is determined to a large extent not by their mineralogical and, respectively, chemical composition, but by the presence of free space in them and its "geometry", i.e. structural features.
It is best to pass through the water rocks with intense fracturing, or composed of disparate crystals of minerals and fragments of rocks.
Hydrogeological features of the Moscow region
In the Moscow region aquifers are relatively deep-lying sands and limestones.
Sands - it is relatively shallow crystalline (with grain sizes from tenths to the first millimeters) sedimentary rocks, mainly composed of quartz and chalcedony (silicon oxide), silicon (a complex mineral composition based on silicon oxide and aluminosilicates). Often, on the outer surface of these minerals and the surface of their intracrystalline microcracks, oxides and iron hydroxides meet, which give them a yellowish-brown hue.
The water content of sand from the point of view of the consumer is not 100%. This can be seen by looking at the hydrogeological map of the Moscow region - as can be seen, most of the sand wells are in the southeast of the Moscow region "crackers".
The composition of the underground waters of sandy horizons, as a rule, does not create problems, although recently, in addition to bacteria, nitrogenous compounds (ammonium, nitrates, nitrites), which are "flickering" in them, heavy metals are also detected.
Limestones in the Moscow region
Limestone called sedimentary rocks, mainly consisting of calcium calcite-calcium carbonate. Most often, outwardly limestone resembles a frozen cement mortar, while the color of limestone is not necessarily greyish-white hues.
Due to the high lithostatic pressure exerted on them by the overlying strata of rocks, limestones have a fine-grained structure and high density. At the same time, most of the limestone deposits are disturbed by fracture systems of various sizes and spatial orientation, over which underground waters move. The water content of limestone, in addition to the general water saturation determined by the nature and intensity of fracturing. The flow rate (water yield per unit time) of wells of the same diameter drilled in limestones of the same horizon can differ by 2 orders of magnitude, i.e. in 100 times.
The ancient limestones of the Carboniferous period lie in the Moscow suburbs at depths of 20 meters (south, southeast, to over two hundred meters (northeast) .The marks are given from the bottom (lower boundary of the layer). The limestone layers can significantly change their thickness (thickness) and form (representing the folds) .In addition, within the deposits of limestones themselves, there may be thin clastic strata of clay and silicified areas.
If the proportion of magnesium carbonate increases, then such limestones are called dolomitized.
Between the layers of sand and limestone, in the greater part of the Moscow suburbs there are powerful clay deposits of the Jurassic period of the Mesozoic Era - the time of the revelry of the dinosaurs - up to 60 m.
According to the age, hydrogeological and hydrogeochemical characteristics of the Moscow Region from the north to the south, five hydrogeological regions are singled out. In each of the areas there are certain horizons of aquiferous limestones, named for the place of their original location or the greatest distribution.
The conventional hydrogeological scheme MO
(major aquifers)
I district
L max, m - 150
H max, m - 50
- Klyazma-Assel (the probable production rate is 0.3 ... 27 l / s)
Composition:
Fe (mg / l) - 0.2 ... 0.7 (excluding Klin and Taldom)
F (mg / l) - 0.2 ... 1
F - 4-7 m-e / l
HCO 3 -, SO 4 -2, Ca 2+, Mg 2+
- Kasimovsky (the probable production rate is 2 ... 8 l / s)
Composition:
Fe (mg / l) - 0.3 ... 0.4 (Dmitrov, Noginsk, Orekhovo-Zuevo - 1.5 ... 3.9)
F (mg / l) - up to 3,6
F - 5.2 ... 6 m-e / l
H 2 S (Dmitrov) - up to 0,003 mg / l
II district
- Kasimovsky (the probable production rate is 0.5 ... 7 l / s)
L max, m - 20 ... 125
H max, m - 10 ... 60Composition:
Fe (mg / l) - 0,2 ... 0,9 - up to 5 (Yegoryevsk, Klin, Solnechnogorsk, Khimki)
F - 3 ... 7 m-e / l
HCO 3 -, Ca 2+, Mg 2+, Na +
- Podol'sko-Myachkovsky - Balashikha, Yegoryevsk, Khimki (the probable debit is 0.5 ... 7 l / s)
L, m - 25 ... 180
H, m - 20 ... 90Composition:
Fe (mg / l) - 0,1 ... 1,0 - up to 6 (Egorievsk, Klin, Solnechnogorsk, Khimki)
F - 3,5 ... 7,2 m-e / l
HCO 3 -, Ca 2+, Mg 2 +, Na +
III district
- West Side:
L max, m - more than 100
H, m - more than 100East End:
L, m - 20 ... 80
H, m - 18 ... 40Composition:
Fe, mg / l - 0.5 ... 2.3 - up to 7.5 (Narofominsk)
Ж, м-э / л - 5 ... 7
H 2 S, mg / l - up to 0,003 (in some places)
IV district
- L, m - 80 ... 160
H, m - 80 ... 100 (up to 150)Composition:
Fe, mg / l - 0.5 ... 2.5
F, mg / l - 0.2 ... 1.0 - up to 4.8 (Mozhaisk)
Ж, м-э / л - 5 ... 7,5
V district
- L, m - 20 ... 80
H, m - 15 ... 30Composition:
F, mg / l - 0,1 ... 1,5
F, mg / l - 0,1 ... 1,5
Ж, м-э / л - 4 ... 7,7
CO 3 2-, Ca 2+, Mg 2+ - 0.4 g / l
The explanations indicate L - the depth of occurrence of limestone in meters (on the sole), H - water pressure in the well (the distance from the surface of the earth to the level of water that has settled after pumping), rigidity (F) and hydrogeochemical characteristics of the water - its salt composition.
The chemical composition of the groundwater of limestone horizons is predominantly hydrocarbonate, calcium-magnesium, often with a high content of iron and fluorine. The maximum permissible concentration (MPC) of iron and fluorine is 0.3 mg / l and 0.7-1.5 mg / l, respectively. Water hardness, determined by the total content of calcium and magnesium, expressed in milligram equivalents per liter, does not formally exceed the MPC level (7 mg-e / l). At the same time, for normal operation of domestic water equipment and for drinking purposes, the rigidity should be reduced to a level of 2.5-3 mg-e / l.
A serious problem can be created by hydrogen sulphide, dissolved in underground water, whose characteristic smell (rotten eggs) is captured at concentrations even in thousandths of mg / l.
The red digits in the diagram are the interval of occurrence of the water-bearing sands, the blue figure below them is the probability (1 = 100%) of the presence of water (according to the actual drilling data of the companies KVO and Mosgeoplan).
A. Sekisov,
hydrogeologist, D.Sc.
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Order of work Library Price list Contacts For a more detailed studygroundwater , carrying out engineering and geological surveys, additional hydro-geological studies are carried out. With their help, engineers identify in situ conditions of occurrence, accumulation, distribution, discharge and composition of groundwater, in particular, determine the conditions and properties that are the criterion for choosing technical measures for the rational use of groundwater (their regulation or prevention). The result of hydrogeological research are hydrogeological maps.Features of hydrogeological maps
These maps primarily reflect the criteria for the occurrence of groundwater and their distribution. The mandatory elements of these cards are:
- data on productivity and quality of aquifers;
- data on the size, shape and position of the foundation of water-pressure systems;
- data on the interaction of relief, geological structure and groundwater.
For the compilation of hydrogeological maps, hydrogeological surveys provide all the necessary information. It is not unimportant to study geological and tectonic maps. Hydrogeological maps provide detailed information on the location and distribution of aquifers, wells, boreholes, karst craters, the base of the aquifer, andchemical composition of groundwater . Geological surveys also provide sections for hydro-geological maps, where one can see the lithological composition of aquifers and their depths, water-proof strata, groundwater salinity, etc.
Map Detailing
Hydrogeological maps, like any other cartographic materials, have a large-scale division:
- small-scale (scale less than 1: 500 000): here you can see important features of the hydrogeological structure of the area, the exact boundaries of the hydrogeological basins, the boundaries of the areas where the origin and availability of various types of groundwater are predominantly. A feature of small-scale maps is the fact that their compilation is often not backed up by hydrogeological surveys. The basis for their development is archival and literary materials.
- medium-scale (scale from 1: 200 000 to 1: 100 000): in addition to the above information, one can also see quantitative data that characterize the state of groundwater over a specific period of time.
- large-scale (scale is more than 1:50 000): the geology of the site is visible here, and their main purpose is to solve special tasks put forward at the stage of detailed design and technical design. Such tasks include: selection of the water intake area, determination of the quantity of groundwater resources, their quantity, forecasting of various measures for drainage and irrigation of the site, etc.
The main difficulty in the compilation of hydrogeological maps is the need to reflect different indicators, which is quite difficult, given the many-level aquifers and complexes and other aspects. Hydrological chart can not display only the geological structure of the earth's surface, just as a geological map displays not only geological objects. Different aspects of the geological structure of the area can be reflected in various structural, reservoir, lithofacies and other maps.
Taking into account the fact that underground waters do not have a continuous uniform distribution, as well as geological age, it is impossible to make the exact equivalent of a conventional geological map. Thus, it is necessary to compile a series of several parallel maps. The multi-level aquifers and complexes are displayed on the map using several techniques, for example, translucence, mapping of sections at various elevations, etc. However, a complete description of the aquifers with a significant number of them can only be given by a series (atlas) of maps. It would be advisable to use parallel cards, which are made of transparent material, and overlap each other during use.
Types of hydrogeological maps
Hydrogeological maps are:
- general purpose; Make an order for geological survey
The chemical composition of water is affected by the geological structure of the terrain, the type, origin of sources, various man-made impacts. For the Moscow region is characterized by a large variety of water-saturated rocks. To drill a well for drinking water It is necessary to know the geological-hydrogeological situation in the region, in which we are helped hydrogeological map of the site.
Geological environment of the Moscow region
The region is located in the center of the Moscow syneclise, which is an oval deflection of the foundation of the Russian platform, the Precambrian period, filled with sedimentary rocks. The bending axis is directed from the east to the north. The depth of the base varies within 1.5-3 km. The surface consists of water-saturated rocks, separated by natural water bodies. Thus, there are closed zones, with different water supply system, chemical and hydrodynamic state of groundwater.
On the bend axis in the northeast, in the upper and marginal parts, limestones, dolomite with interlayers of clay, water with a small mineralization and high head prevail. The slope of the waterproof geological strata in this direction increases the hydraulic pressure in the horizon, contributes to the development of gully erosion.
In the southern regions, there may be small karst craters, superficial growths. Waterlogging often occurs in the lowlands. Monitoring of exogenous processes, development of projects of measures that impede their development, are assigned to state services (GMSN). Specialists of monitoring stations are also tasked with monitoring experienced wells. Services monitor the absence of man-made pollution, changes in the water level. Under observation there are 1081 wells.
Hydrogeological map
The hydrogeological map will help assess the groundwater resources , create a water intake project. If, carry out a water analysis by source of supply, areas of distribution, the following main water horizons will be identified:
But since the groundwater system is dynamic, that is, there must be differences within even one aquifer.
Water supply system in areas of the region is significantly different. The central part has medium and high hardness water, carbonate, magnesium-calcium composition. As the territories are removed, mineralization increases, and the content of chemical elements changes. The Oka-Protvino horizon has a chloride-hydrocarbonate composition. In the Lukhovitsy region, hydrocarbonate-sulfate suspensions. The water horizon of Lyubertsy, Zheleznodorozhny, Balashikha has insignificant technogenic pollution. Virtually everywhere necessary installation of water treatment systems to bring quality to standards.
