Surface water quality assessment. Service for control and supervision in the field of environmental protection, wildlife and forest relations of the Khanty-Mansiysk Autonomous Okrug - Ugra Surface water quality

Surface waters of land - waters that flow (streams) or collect on the surface of the earth (bodies of water). There are sea, lake, river, swamp and other waters. Surface waters are permanently or temporarily in surface water bodies. The objects of surface water are: seas, lakes, rivers, swamps and other streams and reservoirs. Distinguish between salt and fresh land waters.

Surface water formation is a complex process. Streams pouring down from the sky in the form of rain or snow are water evaporated from the seas and oceans. The nature of the terrain through which it flows under the influence of gravity (at the same time, water is the strongest destroyer of that part of the earth's crust located above sea level), the route along which it, gathering in streams and rivers, rushes again to the sea depends. This completes one major phase of the hydrological cycle.

Flowing over the surface, water captures and carries insoluble mineral particles of sand and soil, some of them it leaves on the road, some of them are transferred to the sea, and some substances are dissolved in it.

Surface waters, passing over uneven terrain and falling from rocks, are saturated with oxygen in the air, its compounds with organic and inorganic substances washed out from the land of a particular area and sunlight support a wide variety of life forms in the form of algae, fungi, bacteria, small crustaceans and fish.

In addition, the beds of many rivers are covered with trees, the areas along which they flow, if the river banks are covered with forests. Fallen leaves and needles of trees fall into rivers, they play an important role in filling the water with biological content. Once in water, they dissolve in it. It is this material that later becomes the main cause of contamination of ion-exchange resins, which are used for water purification.

The physical and chemical properties of surface water pollution gradually change over time. Sudden natural disasters can lead to an abrupt change in a short period of time in the composition of surface water sources. Surface water chemistry also changes with the seasons, for example, during periods of heavy rainfall and melting snow (periods of high flood, when the level in rivers rises sharply). This can have a beneficial or unfavorable effect on the characteristics of the water, depending on the geochemistry and biology of the area.

Surface water chemistry also changes throughout the year in several cycles of drought and rain. Long periods of drought seriously affect water scarcity for industrial use. In places where rivers flow into the sea, salt water can enter the river during drought periods, which creates additional problems. Industrial users should be guided by the variability of surface waters, be sure to take into account when designing treatment facilities and developing other programs.

Surface water quality depends on a combination of climatic and geological factors. The main climatic factor is the amount and frequency of precipitation, as well as the ecological situation in the region. Precipitation carries with it a certain amount of undissolved particles such as dust, volcanic ash, plant pollen, bacteria, fungal spores, and sometimes larger microorganisms. The ocean is the source of various salts dissolved in rainwater. It contains ions of chloride, sulfate, sodium, magnesium, calcium and potassium. Industrial air emissions also "enrich" the chemical palette, mainly due to organic solvents and nitrogen and sulfur oxides that cause acid rain. Agricultural chemicals also contribute. The geological factors include the structure of river channels. If the channel is formed by limestone, then the water in the river is usually clear and hard. If the channel is made of impermeable rocks, for example granite, then the water will be soft, but muddy due to the large amount of suspended particles of organic and inorganic origin. In general, surface waters are characterized by relative softness, high organic content and the presence of microorganisms.

Surface waters include streams, reservoirs, swamps and glaciers. In natural (rivers, streams) and artificial (canals) watercourses, water moves along the channel in the direction of the general slope of the surface. Watercourses can be permanent or temporary (drying up or freezing).

A reservoir is an accumulation of water in a natural (lake) or artificial (reservoir, pond) depression, the flow from which is absent or slowed down. Only a small part of the hydrosphere is contained in rivers, about four times less than in swamps, and sixty times less than in lakes.

The importance of rivers in the water cycle is immeasurably greater than the water they contain, since the water in the rivers is renewed on average every 19 days.

For comparison, in swamps, complete water renewal occurs in 5 years, in lakes - in 17 years.

Due to the flow of water, the rivers are better saturated with oxygen and the water quality is better here. It was along the banks of the rivers that the first human settlements arose.

Rivers for a long time served as the main transport arteries and defensive lines, were sources of water and fish. A river is usually called a natural constant water flow flowing in a depression (channel) developed by it. River valleys are elongated depressions on the earth's surface, developed by constant water flows. All river valleys have slopes and a flat bottom. The water flow constantly carries a lot of erosion products, which are deposited in the bottom of the valley or carried out into the sea. River sediments are called alluvium. Especially a lot of alluvium accumulates in the bottoms of valleys in the lower reaches of rivers, where the slopes of the surface are the least. When the snow melts, part of the bottom (floodplain) is filled with hollow waters. A river stream always tends to deepen its bed to a certain level. This level is called the base of erosion. For a river, the basis of erosion is the level of the sea, lake or other river where this river flows. The river is constantly deepening its channel and the time comes when the river can no longer flood its floodplain during high water. The river begins to develop a new floodplain at a lower level, and the old floodplain turns into a terrace - a high step at the bottom of the river valley. The older and larger the river, the more terraces can be found in its valley.

In reality, a river is a complex natural formation (system), consisting of many elements. The area from which the river system collects its waters is called the river basin. Between adjacent river basins there is a border - a watershed.

The Amazon River has the largest basin, it is also the most abundant river (the average annual flow is 220,000 cubic meters per second).

The density of the river network depends on many factors: first of all, on the general moistening of the territory - the greater it is, the greater the density of rivers, as, for example, in the tundra and forest zones; from the relief and geological structure of the territory - in the areas where soluble and fissured (karsting) limestones are spread, the river network is sparse, and the rivers, as a rule, are shallow and dry.

All rivers have a beginning and an end. The beginning of the river, the place where a permanent watercourse appears, is called the source. The source can be a lake, swamp, spring or glacier.

Estuary - the place where a river flows into the sea, lake or one river into another. In a number of large northern rivers, the estuaries look like narrow funnel-shaped bays - they are called estuaries. In estuaries, river sediments are carried out into the sea under the action of waves and currents. Large estuaries have rivers such as the Congo in Africa, the Thames and Seine in Europe, and the Russian rivers Yenisei and Ob. In contrast to them, in deltas, on the contrary, rivers literally wander, flowing into the sea, among their own sediments, breaking into numerous branches and channels. The largest deltas have rivers - the Amazon, Yellow River, Lena, Mississippi, etc.

The relief of the area directly affects the slope of the river bed and, accordingly, the speed of water flow. The difference in the elevation of the water surface in the river at two points located at some distance along its course is called the fall of the river. The slope of a river is the ratio of the fall of the river to its length. Falling water from a steep ledge is called a waterfall.

The highest waterfall on Earth is Angel (1054 m) in the Orinoco river basin. The widest (1800 m) is Victoria on the river. Zambezi (its height is 120 m.). Plain rivers usually flow calmly and smoothly, with a slight dip and slight inclines. Large rivers have wide valleys and are convenient for navigation. Mountain rivers have great slopes and, therefore, a rapid current, narrow rapids deep valleys. The water in the channel rushes at a breakneck speed, foams, forms whirlpools and waterfalls.

Mountain rivers are usually unsuitable for navigation, but they have large reserves of hydropower and are convenient for the construction of hydropower plants.

For the national economy (shipping, construction of hydroelectric power plants, water supply to settlements, irrigation of fields), very important characteristics of rivers are water flow (the amount of water passing through the channel per unit of time) and annual flow (water flow in a river per year).

The value of the annual runoff characterizes the water content of the river and depends on the climate (the ratio of precipitation and evaporation in the area of \u200b\u200bthe river basin) and relief (flat relief reduces runoff, mountain relief, on the contrary, increases it).

The value of the material carried by water, consisting of chemical and biological substances dissolved in water and solid small particles, - the value of solid runoff - depends on the speed and resistance to erosion of rocks. Climatic conditions affect the feeding and regime of rivers (glacial, snow, rain and soil). The predominant type of feeding determines the intra-annual distribution of runoff - the regime of rivers. The regime of rivers is the life of a river flow for a certain time (days, seasons and years). According to the regime, the rivers are subdivided into several main groups. On rivers with spring floods and mainly snow supply. Relatively rapid melting of the snow cover leads to the rise and overflow of water (spring flood). In the summer, the rivers switch to rainwater supply and, although there is a large amount of precipitation, due to increased evaporation, these rivers become shallow. Low-water periods are noted on the rivers - a time of stable low water level in the channel. In winter, during freeze-up (freezing and the formation of stationary ice), rivers are fed exclusively by groundwater and winter low water is observed. The leash mode is typical for rivers with rain and mixed feeding. Floods are short-term (sometimes very significant) rises of water in a river - unlike floods, they can occur at any time of the year and are most often associated with heavy rains. In warm winters, floods can occur at this time of the year.

Late melting of snow and glaciers in the mountains causes summer floods. This regime is characterized, for example, by rivers originating in the Alpine mountains. Rivers with a monsoon climate are characterized by a flood regime in the second half of summer and a winter low season. Due to the thin snow cover, the spring flood is weak or completely absent. Monsoons often bring heavy rainfall with a torrential character, which leads to catastrophic floods. At this time, vast territories with numerous villages are under water. Buildings are destroyed, crops, animals and even people perish. The rivers of East and South Asia are especially violent: Amur, Huang He, Yangtze, Ganges.

Lakes differ not only in size and depth, but also in the color and properties of the water, the composition and number of organisms inhabiting them. The number of lakes (lakes in the territory) is affected by the increased humidity of the climate and the relief with numerous closed basins. The size, depth, shape of the lakes largely depend on the origin of their basins. There are basins of tectonic, glacial, karst, thermokarst, stanitsa and volcanic origin. There are also dammed (dammed or dammed) lakes, formed as a result of blocking the river channel with blocks of rocks during collapses in the mountains.

Tectonic lake basins are large and deep, as they formed at the site of subsidence, cracks and faults in the earth's crust. The largest lakes in the world are classic tectonic lakes: the Caspian and Baikal in Eurasia, the Great African and North American lakes.

Glacial lake basins are formed during the plowing activity of glaciers or as a result of erosion or accumulation of glacial waters in areas of accumulation of glacial material and the formation of glacial landforms. There are many such lakes in Finland, in the north of Poland, in Karelia and others.

Karst lake basins are formed as a result of sinkholes, subsidence and erosion, primarily of readily soluble rocks: limestone, dolomite, gypsum, and salts. There are many thermokarst lakes in the permafrost zone in the tundra and forest-tundra. Here water dissolves underground ice.

Ancient lakes are the remains of abandoned river channels.

Volcanic lake basins have arisen in volcanic craters or in depressions of lava fields. These are Kronotskoye and Kuril lakes, lakes in New Zealand. According to the salinity, the lake waters are divided between fresh and salty. Unlike rivers, the regime of lakes depends on whether the rivers flow out of it are a flowing lake (Baikal) or it is a closed body of water (Caspian).

Swamps are land areas with abundant, stagnant or low-flow soil moisture for most of the year, with characteristic (bog) vegetation, lack of oxygen and constant peat formation (the peat layer should reach at least 0.3 m, if there is less peat, this will be Wetlands. Peat is called semi-decomposed plant remains. Bogs cannot be called reservoirs, as they contain water in a bound state. But marshes contain only 5-10% of dry matter (peat), the rest is water. Therefore, marshes are important accumulators of fresh water. Swamping is facilitated by the presence of a close aquiclude and they are most common in areas with permafrost. The most common swamps in the forests of the Northern Hemisphere, as well as in Brazil and India. Due to the abundance of swamps and swampy forests, the forest zone in Western Siberia is called forest bog. the largest swamp in the world is Vasyugan. The processes of waterlogging in this region continue in the present her time. The average horizontal speed of the spread of the edges of the bogs and their advance on the surrounding forests is 10-15 cm per year.

The methods of forming swamps are different. This is overgrowing, peat formation of reservoirs (lakes) and stagnation of water in the places where springs come out and in the case of close occurrence of groundwater; as well as the accumulation of moisture in depressions and flat areas under forests and meadows (forest clearings are especially often swamped.) According to the sources of food, they are distinguished by upstream (they feed on atmospheric waters), lowland (ground moisture) and transitional bogs. When classified according to the degree of substrate richness, they correspond to oligotrophic (poor), eutrophic (rich), and mesotrophic. Lowland bogs are formed mainly in the lowest areas of the relief (in floodplains, ancient lake basins).

Groundwater is highly mineralized and, entering the swamp, they enrich it. Therefore, sedges, horsetails, reeds, mosses grow in a dense continuous cover in lowland bogs, thickets of black alder are often found. Many birds usually find shelter here, and their droppings, containing nitrogenous substances, also enrich the swamp.

Lowland peat is an excellent fertilizer.

Upper bogs are formed most often in watersheds, they are moistened by atmospheric waters, very poor in nutrients, and the vegetation here is completely different. These are mainly mosses and stunted trees. Peat of raised bogs with poor vegetation contains little ash, therefore it is a combustible mineral and is used as a fuel.

Bogs are of great importance for water protection. Accumulating huge reserves of water, they regulate the water regime of rivers and maintain the stability of the water balance of the territory; purify the water passing through them. Swamps are the source of many rivers. The vegetation of the bogs is of no particular food value. But after draining, they are used for agricultural or forest crops. However, small rivers often become shallow and disappear.

Surface water pollution

The water quality of most water bodies does not meet regulatory requirements. Long-term observations of the dynamics of surface water quality reveal a tendency to increase the number of sections with a high level of pollution and the number of cases of extremely high content of pollutants in water bodies. The state of water sources and centralized water supply systems cannot guarantee the required quality of drinking water, and in a number of regions (South Urals, Kuzbass, some territories of the North) this state has reached a dangerous level for human health. Services of sanitary and epidemiological supervision constantly note high pollution of surface waters. About 1/3 of the total mass of pollutants is introduced into water sources with surface and storm runoff from the territories of sanitary uncomfortable places, agricultural facilities and land, which affects the seasonal, during the spring flood, deterioration in the quality of drinking water annually observed in large cities, including including in Novosibirsk. In this regard, water is hyperchlorinated, which, however, is unsafe for public health due to the formation of organochlorine compounds.

One of the main pollutants of surface waters is oil and oil products. Oil can get into the water as a result of natural outflows in the areas of occurrence.

But the main sources of pollution are associated with human activities: oil production, transportation, processing and use of oil as fuel and industrial raw materials.

Among industrial products, toxic synthetic substances occupy a special place in terms of their negative impact on the aquatic environment and living organisms.

They are finding ever more widespread use in industry, transport, and public utilities. The concentration of these compounds in wastewater, as a rule, is 5-15 mg / l with a maximum concentration limit of -0.1 mg / l. These substances can form a layer of foam in water bodies, which is especially noticeable on rapids, rifts, sluices.

Foaming ability of these substances appears already at a concentration of 1-2 mg / l. The most common pollutants in surface waters are phenols, easily oxidizable organic substances, copper and zinc compounds, and in some regions of the country - ammonium and nitrite nitrogen, lignin, xanthates, aniline, methyl mercaptan, formaldehyde, etc. A huge amount of pollutants is introduced into surface water with waste water from enterprises of ferrous and non-ferrous metallurgy, chemical, petrochemical.

Oil, gas, coal, timber, pulp and paper industries, agricultural and communal enterprises, surface runoff from adjacent territories. Mercury, lead and their compounds pose a small hazard to the aquatic environment from metals. Expanded production (without treatment facilities) and the use of pesticides in the fields lead to severe pollution of water bodies with harmful compounds.

Pollution of the aquatic environment occurs as a result of the direct introduction of pesticides during the treatment of reservoirs for pest control, the ingress of water into reservoirs flowing from the surface of the treated agricultural land, when discharging waste from manufacturing enterprises into reservoirs, as well as as a result of losses during transportation, storage and partially atmospheric precipitation. Along with pesticides, agricultural wastewater contains a significant amount of fertilizer residues (nitrogen, phosphorus, potassium) applied to the fields.

In addition, large quantities of organic compounds of nitrogen and phosphorus enter with wastewater from livestock farms, as well as with sewage. An increase in the concentration of nutrients in the soil leads to a violation of the biological balance in the reservoir. Initially, the number of microscopic algae increases sharply in such a reservoir. As the food supply increases, the number of crustaceans, fish and other aquatic organisms increases. Then a huge number of organisms die off. It leads to the consumption of all oxygen reserves contained in the water and the accumulation of hydrogen sulfide. The situation in the reservoir changes so much that it becomes unsuitable for the existence of any forms of organisms. The reservoir gradually "dies".

The current level of wastewater treatment is such that even in waters that have undergone biological treatment, the content of nitrates and phosphates is sufficient for intensive eutrophication of water bodies.

Eutrophization - enrichment of a reservoir with nutrients, stimulating the growth of phytoplankton. From this, the water becomes cloudy, benthic plants perish, the concentration of dissolved oxygen decreases, fish and mollusks living in the depths suffocate.

Disinfection and disinfection of surface waters

Another important block of any installation is a block for water disinfection and disinfection. Disinfection usually means the purification of surface water from all types of living microorganisms, including not only organisms potentially hazardous to human health, such as bacteria and viruses, but also microalgae that can harm equipment, pipelines and other objects in contact with contaminated water. And in order, for example, to avoid the ingress of similar harmful substances into the soil, they use autonomous country sewage systems, information about which can be taken into account, for sure, very useful. Today, there are several methods of wastewater treatment, each of which has both its own advantages and disadvantages, we will dwell on some of them in more detail.

One of the most widespread methods of surface water purification from potentially dangerous microorganisms is their oxidation with the help of various reagents. The cheapest method is water chlorination, as this reagent is considered to be the cheapest. A more expensive, but more reliable and safer reagent is ozone, which, after purification, simply decomposes into harmless compounds such as air, water or carbon dioxide, in contrast to chlorine, which remains in water and can harm both the human body and household or industrial technique.

Another method of cleaning surface water from microorganisms is irradiation of water with ultraviolet light, which is considered one of the most effective and safe methods of water disinfection. When water is irradiated, ultraviolet light penetrates the nucleus of living cells, causing irreversible damage to the DNA of the latter, which causes the microorganism to lose its ability to reproduce. Cleaning by ultraviolet radiation is today considered one of the most environmentally friendly technologies for water disinfection, which guarantees high quality and good results.

1

The work reflects the main results of assessing the water quality of the Upper Volga reservoir for the period 2011–2014. The analysis of the hydrochemical data of the reservoir waters has been carried out. Priority pollutants were identified, which include manganese, total iron, color, ammonium ion, oil products. The results of calculating integral indicators of water quality are given: indexes WPI (Index of Water Pollution), IQI (General Sanitary Index of Water Quality) and UKIZV (Specific Combinatorial Index of Water Pollution). An assessment of the water quality of the Upper Volga reservoir was carried out. In general, the water quality of the Verkhnevolzhsky reservoir was assessed as “dirty” (according to the value of the WPI index), moderately polluted (according to the value of the AQI index), and very polluted water (according to the value of the UCIZV index) according to the value of integral hydrochemical indices.

water quality

Upper Volga reservoir

integral quality indices

1. Upper Volga reservoir // Great Soviet encyclopedia. - M .: Soviet encyclopedia, 1969-1978. URL: www./enc-dic.com/enc_sovet/Verhnevolzhskoe_vodohranilische-3512.html (date accessed: 17.07.15).

2. Hydrochemical indicators of the state of the environment: reference materials / ed. T.V. Guseva. - M .: Forum: INFRA-M, 2007 .-- 192 p.

3. Lazareva G.A., Klenova A.V. Assessment of the ecological state of the Upper Volga reservoir by hydrochemical indicators // Proceedings of the VII international scientific conference of young scientists and talented students "Water resources, ecology and hydrological safety" (Moscow, IVP RAS, Russian Academy of Natural Sciences, December 11-13, 2013) ... - M., 2014. - S. 173-176.

4. RD 52.24.643-2002 Method of complex assessment of the degree of pollution of surface waters by hydrochemical indicators - Roshydromet, 2002. - 21 p.

5. Shitikov V.K., Rosenberg G.S., Zinchenko T.D. Quantitative hydroecology: methods of systemic identification. - Togliatti: IEVB RAS, 2003 .-- 463 p.

The water quality of water bodies is formed under the influence of both natural and anthropogenic factors. As a result of human activity, many pollutants of varying degrees of toxicity can enter water bodies. Water bodies are polluted by drains of agricultural and industrial enterprises, waste waters of settlements. In modern conditions, the problem of providing the population with clean water is becoming more and more urgent, and the study of the state of water bodies is one of the most important tasks.

The purpose of this work is the assessment of the water quality of the Upper Volga reservoir using integral quality indicators.

Objects and research methods

The Upper Volga reservoir was created in 1843 (reconstructed in 1944-1947) and consists of interconnected lakes Sterzh, Vselug, Peno and Volgo. The reservoir is located in the north-west of the Tver region in the Ostashkovsky, Selizharovsky and Penovsky districts. The reservoir's surface area is 183 km2, volume - 0.52 km3, length - 85 km, maximum width 6 km. The length of the coastline is 225 km. With a high water level, close to the normal retaining level (206.5 m), the reservoir is a single reservoir, and during low water, with strong drainage, it is divided into lakes, poorly communicating with each other. The water resources of the Upper Volga reservoir are used in the summer low-water period to regulate the levels in the upper Volga, as well as for industrial purposes, communal needs, in agriculture and animal husbandry. The reservoir is of great importance for recreation, tourism and fishing.

During the research, 3 sections of the Verkhnevolzhsky reservoir were studied (section of Lake Volgo, settlement Peno; section of Lake Volgo, village Devichye; section of Verkhnevolzhsky beishlot) (Fig. 1) according to hydrochemical indicators for the period from 2011 to 2014.

Figure 1. Schematic map of sampling stations of the Verkhnevolzhsky reservoir: 1 - section of the lake. Volgo, settlement Peno, 2 - section of the lake. Volgo, village Devichye, 3 - target Verkhnevolzhsky beishlot

The work used the data provided by the Dubna Ecoanalytical Laboratory (DEAL) of the Federal State Budgetary Institution "Centerregionvodkhoz", on such hydrochemical indicators as: pH, color, ammonium ion, nitrate ion, nitrite ion, phosphate ion, total iron, chloride ion , sulfate ion, manganese, magnesium, biochemical oxygen demand, copper, zinc, lead, petroleum products, dissolved oxygen, nickel.

Research results

The analysis of hydrochemical data showed that all the studied sections of the Verkhnevolzhsky reservoir are characterized by a high content of manganese, total iron and ammonium ion, the concentrations of which always exceeded the MPCv; in some periods, the MPCv was exceeded for oil products. The concentrations of these substances changed insignificantly during the study period.

To assess the water quality of the Upper Volga reservoir for 2011-2014. integral indicators of water quality were calculated: indexes WPI (Water Pollution Index), IQI (General Sanitary Index of Water Quality) and UKIZV (Specific Combinatorial Index of Water Pollution). The results are shown in Table 1.

Table 1

The value of the WPI, IKV, UKIVZ indices, water quality class, qualitative and ecological state of waters in the sections of the Verkhnevolzhsky reservoir

Index value along the sections
Area of \u200b\u200bthe lake. Volgo, p. Peno
Water quality class Quality condition				very dirty
Water quality class Quality condition		moderately polluted	moderately polluted	moderately polluted
Class and rank Quality condition		very polluted	very polluted	contaminated
Area of \u200b\u200bthe lake. Volgo, village Devichye
Water quality class Quality condition
Water quality class Quality condition		moderately polluted	moderately polluted	moderately polluted
Section Verkhnevolzhsky beyslot
Water quality class Quality condition				very dirty

Continuation of Table 1

Index value along the sections
Water quality class Quality condition	moderately polluted	moderately polluted	moderately polluted	moderately polluted
Class and rank Quality condition	very polluted	very polluted	very polluted	very polluted

The hydrochemical index of water pollution (WPI) was used as the main integrated indicator of water quality until 2002. Classification of water quality according to WPI values \u200b\u200bmakes it possible to divide surface waters into 7 classes depending on the degree of their pollution. The WPI calculation is carried out for six ingredients: mandatory - dissolved oxygen and BOD5, and 4 substances that had the highest relative concentrations (Ci / MPCi). The main disadvantage of this method for assessing water quality is that a small range of pollutants is taken into account.

The maximum values \u200b\u200bof the WPI index in all sections are observed in the winter-spring period, and the minimum - in the autumn period. According to the WPI index in 2011-2013, in all sections, the water quality is assessed as “dirty” (water quality class - 5). In 2014, in the section of the Verkhnevolzhsky beishlot (No. 3), there is a deterioration in the quality of water up to the 6th quality class - "very dirty", while in the sections of the lake. Volgo p. Peno (No. 1) and the lake. Volgo village Devichye (No. 2) water quality has not changed (Fig. 2).

Figure 2. Change in WPI index values \u200b\u200bin the sections of the reservoir for 2011-2014.

To determine the general sanitary water quality index (ICW), a point assessment is carried out (from 1 to 5 points). Points are assigned to each indicator used for the calculation, the weight of the indicator is also taken into account, after which the value of the ICV is determined.

In general, according to the values \u200b\u200bof the AQI index during the period under consideration (2011-2014), in all sections of the water during almost the entire study period, with a few exceptions, are characterized as “moderately polluted” (class 3 of water quality) (Fig. 3).

Figure 3. Change in the values \u200b\u200bof the AQI index in the sections of the reservoir for 2011-2014.

The specific combinatorial index of water pollution (UCIPI) is now becoming a priority in assessing water quality. The classification of water quality according to the values \u200b\u200bof the UKIZV makes it possible to divide surface waters into 5 classes, depending on the degree of their pollution. In contrast to WPI, this approach to the calculation determines not only the frequency of exceeding the MPC, but also determines the frequency of cases of exceeding the standard values. The data on the calculation of the UKIZV index allow more accurate reflection of the quality of surface waters.

According to the value of the UCIPR index, the waters of the Upper Volga reservoir during the observed period (2011-2014) in all sections are assessed as "very polluted" (class 3, category "B"), with the exception of the section in the section of Lake Volgo Peno settlement in 2014, where the degree of water pollution is characterized as "polluted" (class 3, category "A") (Fig. 4).

Figure 4. Change in the values \u200b\u200bof the UCIZV index in the sections of the reservoir for 2011-2014.

An increase in the values \u200b\u200bof the UKIVZ index was noted in the sections located downstream of the reservoir, and although they do not go beyond the values \u200b\u200bof one quality class and category, this indicates a slight deterioration in water quality. In the sections near the village of Devechye and the Verkhnevolzhsky beishlot, the value of the index in 2013 is slightly higher than in the other years of the studied period.

findings

Thus, as a result of the work carried out, priority pollutants and indicators of the waters of the Upper Volga reservoir were identified, which include manganese, total iron, color, ammonium ion and oil products. The water quality of the Upper Volga Reservoir was assessed as “dirty” (class 5) according to the WPI index value, as “moderately polluted” (class 3) according to the ICV index value, and as “very polluted” water (class 3, category "B"). The use of the UKIZV index gives more accurate information about the class of surface water condition, because when calculating it, all hydrochemical indicators determined in the sample are used.

Reviewers:

Zhmylev P.Yu., Doctor of Biological Sciences, Professor of the Department of Ecology and Earth Sciences, Faculty of Natural and Engineering Sciences, State Budgetary Educational Institution of Higher Education "State University" Dubna "", Dubna.

Sudnitsin II, Doctor of Biological Sciences, Professor of the Department of Ecology and Earth Sciences, Faculty of Natural and Engineering Sciences, State Budgetary Educational Institution of Higher Education “Dubna State University”, Dubna.

Bibliographic reference

Lazareva G.A., Klenova A.V. ASSESSMENT OF SURFACE WATER QUALITY BY INTEGRATED INDICATORS (ON THE EXAMPLE OF THE VERKHNEVOLZHSKY RESERVOIR) // Modern problems of science and education. - 2015. - No. 6 .;
URL: http://science-education.ru/ru/article/view?id\u003d23406 (date accessed: 03/20/2020). We bring to your attention the journals published by the "Academy of Natural Sciences"

The quality of water is determined by its physical, chemical and biological characteristics, on which the suitability of water for one or another type of its use depends. Chemical pollution of natural waters, first of all, depends on the amount and composition of wastewater from industrial enterprises and public utilities discharged into water bodies. A significant part of pollutants enters water bodies also as a result of their washing away by melt and rainwater from the territories of settlements, industrial sites, agricultural fields, livestock farms. Poor water quality can also be caused by natural factors (geological conditions, feeding of rivers with waters with a high organic content, etc.).

Of all the types of pollutants entering water bodies, only registered wastewater discharges can be quantified. The background on the map shows the annual discharge of dissolved pollutants in wastewater (in conventional tons), per 1 sq. km of the territory of the relevant water management area, which is most often the catchment area of \u200b\u200ba medium-sized river or individual parts of a large river basin, sometimes - a lake catchment area. Conventional tons are determined taking into account the harmfulness (hazard) of individual pollutants by introducing a weight coefficient for each substance, which is numerically equal to the reciprocal of the maximum permissible concentration of this substance. The most common pollutants with large weight coefficients (100-1000) are phenols, nitrites, etc. Chlorides and sulfates, which, along with organic matter, form the bulk of substances contained in wastewater, have the lowest weight coefficients (0.3-0, five).

The largest intake of the mass of dissolved substances in the composition of wastewater is characterized by water management areas, within which there are several cities with a significant volume of wastewater. A similar result is obtained with a relatively small volume of wastewater, but with pollutants characterized by large weight coefficients. The low intensity of pollutants entering the water bodies in the composition of wastewater is mainly distinguished in the north of Siberia and the Far East, with the exception of the area within which the city of Norilsk is located.

The main criterion for the quality of water in rivers and reservoirs is the average multiplicity of exceeding the maximum permissible concentration of the main pollutants by their actual content in water, determined on the State Observation Network by the Hydrometeorology and Environmental Monitoring Departments of Roshydromet.

At water bodies that do not have points of stationary monitoring of water quality, it is determined by analogy with water bodies on which such observations are carried out, or on the basis of an expert assessment of the impact on water quality of a complex of factors, first of all, the presence of sources of pollution of natural waters, as well as dilution capacity of water bodies.

“Extremely dirty” waters are found mainly in small rivers with low dilution capacity. When even a relatively small volume of wastewater is discharged into them, the average annual concentration of individual pollutants can exceed the maximum permissible concentration by 30–50, and sometimes more than 100 times. This class is inherent in some medium-sized rivers (for example, Chusovaya), into which wastewater with a high content of the most dangerous pollutants is discharged.
The class “dirty” includes water bodies with average annual concentrations of individual pollutants up to 10–25 maximum permissible concentration. This situation can be observed both on small and on large rivers or their individual sections. The pollution of some large rivers (for example, the Irtysh) is associated with shipping.

“Significantly polluted” water bodies are characterized by average annual concentrations of pollutants up to 7-10 maximum permissible concentration. They are typical for many water bodies located in the most economically developed regions of the European part of Russia and the Urals. The pollution of rivers is mainly associated with mining, rivers - with the gold mining industry, rivers and the Lower Tunguska - with the washout of pollutants from the territories of coastal economic facilities. The source of pollution of rivers flowing in forested areas can be the rafting of wood, especially molar.

In “slightly polluted” water bodies, the average annual concentrations of certain pollutants are 2–6 times higher than the maximum permissible concentration, and in “conditionally clean” water bodies, this can be observed only for short periods of time.

Water bodies of "slightly polluted" and "relatively clean" rivers prevail in the north of the European part of Russia and the Far East.

Despite the fact that the volumes of polluted wastewater discharges in Russia as a whole in the 2000s, compared with the early 1990s, decreased by 20–25%, there is no improvement in water quality, and often even its deterioration is noted. ... This is due to a number of reasons, including a significant accumulation of pollutants in the bottom sediments of rivers and, as well as in the soils and grounds of their basins, a decrease in the efficiency of treatment facilities, and more frequent cases of emergency pollution of natural waters. The deterioration of water quality indicators is partly due to the tightening of the maximum permissible concentration for some substances (for example, iron).

Among the pollutants contained in surface waters, most often (in 50-80% of samples) the values \u200b\u200bof the maximum permissible concentration exceed the content of copper (Cu) and iron (Fe), as well as the value of biological oxygen consumption, which characterizes the content of readily soluble organic substances. A 10-fold excess of the maximum permissible concentration in more than 10% of the samples was noted for the same substances. Certain regions of Russia are characterized by the presence of specific pollutants in water bodies: lignin, lignosulfonates, sulfides, hydrogen sulfide, organochlorine, methanol, mercury compounds. Some pollutants pass from the aquatic environment into bottom sediments and can serve as a source of secondary water pollution.

The concept of water quality includes a set of indicators of the composition and properties of water that determine its suitability for specific types of water use and water consumption. Requirements for water quality are regulated by the "Rules for the protection of surface waters from pollution by sewage" (1974), "Sanitary rules and regulations for the protection of surface waters from pollution" "(1988), as well as existing standards. [...]

By the nature of water use and regulation of water quality, reservoirs are divided into two categories: 1 - drinking and cultural and domestic purposes; 2 - for fishery purposes. In water bodies of the first type, the composition and properties of water must comply with the standards in sections located at a distance of 1 km upstream of watercourses and within a radius of 1 km from the nearest water use point. In industrial reservoirs, water quality indicators should not exceed the established standards at the place of wastewater discharge in the presence of a current, in the absence of it - no more than 500 m from the place of discharge. [...]

Water quality is assessed according to the following parameters: the content of suspended and floating substances, smell, taste, color, water temperature, pH value, the presence of oxygen and organic matter, the concentration of harmful and toxic impurities (Table 2.2-2.4). [...]

Harmful and poisonous substances, depending on their composition and nature of the action, are normalized according to the limiting hazard indicator (LPV), which is understood as the greatest negative effect of these substances. When assessing the quality of water in reservoirs for drinking and cultural and domestic purposes, three types of LPV are used: sanitary-toxicological, general sanitary and organoleptic; in fishery reservoirs, toxicological and fishery LPV are added to these three. [...]

The above water quality assessments are based on a comparison of the actual values \u200b\u200bof individual indicators with the normative ones and refer to single ones. Due to the complexity and diversity of the chemical composition of natural waters, as well as the increasing number of pollutants, such assessments do not give a clear idea of \u200b\u200bthe total pollution of water bodies and do not allow to unambiguously reflect the degree of water quality with different types of pollution. To eliminate this deficiency, methods for a comprehensive assessment of surface water pollution have been developed, which are fundamentally divided into two groups. [...]

The first includes methods that allow assessing the quality of water by a combination of hydrochemical, hydrophysical, hydrobiological, microbiological indicators (Table 2.4). Water quality is divided into classes with varying degrees of pollution. However, the same state of water according to different indicators can be attributed to different quality classes, which is a disadvantage of these methods. [...]

The second group consists of methods based on the use of generalized numerical characteristics of water quality, determined by a number of basic indicators and types of water use. These characteristics are water quality indices, coefficients of its pollution. [...]

In hydrochemical practice, a method for assessing water quality, developed at the Hydrochemical Institute, is used. The method allows an unambiguous assessment of water quality based on a combination of the level of water pollution by the totality of pollutants in it and the frequency of their detection. [...]

According to the value of the combinatorial pollution index, the class of water pollution is established (Table 2.5). [...]

For a comprehensive assessment of water bodies, taking into account the pollution of both water and bottom sediments, the methodology developed in IMGRE is used (Table 2.6).

Surface water quality

The hydrographic network of the Autonomous Okrug includes about 290 thousand lakes and thirty thousand watercourses, most of which are small rivers. The main waterway is the Ob River, which receives large tributaries: Irtysh, Vakh, Agan, Tromyegan, Bolshoi Yugan, Lyamin, Lyapin, Pim, Severnaya Sosva, Kazym. The total length of the hydraulic network is about 172 thousand km.

Most of the rivers are of the flat type, have a slow flow, wide floodplains and a large number of channel lakes. Freezing up begins in October, during the winter small rivers and lakes freeze to the bottom. Ice drifts from early May to early June.

The rivers are characterized by a highly extended flood, a reduced drainage role, which is one of the important factors of waterlogging and waterlogging of the territory. Swampiness of river catchments reaches 50-70% and more. The influence of bog waters largely determines the regional hydrochemical characteristics of both river waters and ground waters of surface aquifers.

The surface waters of the Autonomous Okrug are experiencing a powerful anthropogenic load associated with the active development of the infrastructure of cities and the largest oil and gas production complex in Russia in recent decades.

In landscape-geochemical studies, the hydrographic network is considered as the main block through which flows of natural and man-made substances pass. The dynamics of the chemical composition of surface waters is an indicator of the regional ecological situation. This determines the importance of hydrochemical studies, which constitute the most important section of the territorial system of ecological monitoring of Ugra.

The characteristics of surface water quality are presented based on the results of monitoring at 34 Roshydromet sites and 1,692 local points of the territorial observation network (Figure 1).

Observations at the posts of the state observation network (federal stations) are provided by Roshydromet (executor - Khanty-Mansiysk Central Hydrometeorological Service) on 16 large watercourses (Ob with channels, Irtysh, Vakh, Agan, Trom-Yugan, Bolshoi Yugan, Konda, Kazym, Nazym, Pim, Amnya, Lyapin, Severnaya Sosva) near settlements. The annual volume of measurements is about 8000 pieces.

Figure 1. Points of surface water monitoring on the territory

The functioning of local observation points of the territorial system is provided by subsoil users and the Government of the Autonomous Okrug (coordinator - Ugra Prirodnadzor). Local monitoring points cover 700 large and small watercourses within the boundaries of licensed subsoil areas, experiencing the main load from the oil and gas complex. In 2018, within the boundaries of 308 licensed subsoil plots, 91,080 water quality measurements were made.

The river waters of Ugra have a number of hydrochemical features. They are characterized by low mineralization, increased values \u200b\u200bof ammonium and metal ions caused by the presence of a large amount of organic compounds in river and lake waters, intense coloration and low transparency of waters (Table 1).

Natural landscape-geochemical conditions caused almost widespread excess of maximum permissible concentrations (hereinafter - MPC) for iron (in 94-98% of samples), manganese (in 75-91% of samples), zinc (in 29-53% of samples) and copper ( in 60-73% of samples) (Figure 2).

The reasons for this are the geochemical features of boggy taiga landscapes with their inherent acidic reaction of soils and a wide distribution of the restorative environment. Iron, manganese, zinc and copper have a high migration capacity in the landscapes of the acidic gley class, therefore, they intensively flow from soils into groundwater and then into rivers.

Table 1

Average content of pollutants and parameters

Indicator								The ratio of the average in 2018 to the MPC
								acidification
	mgO 2 / dm 3
Hydrocarbons
Sulphates
Manganese

Long-term observations show that the average concentrations of these substances are in the range:

iron - 1.35-1.86 mg / dm 3, or 13-18 MPC;

manganese - 0.09-0.18 mg / dm 3, or 9-18 MPC;

zinc - 0.01-0.02 mg / dm 3, or 1-2 MPC;

copper - 0.003 - 0.007 mg / dm 3, or 3-7 MPC.

Figure 2. Distribution of measurements of iron and manganese compounds

regarding the environmental standard

Significant seasonal fluctuations in the hydrochemical composition are also a characteristic natural feature of the surface waters of the Autonomous Okrug. The maximum values \u200b\u200bof pollution indicators are achieved during the winter low-water period, when low water flows and water temperature contribute to an increase in the concentration of substances.

For the period 2010-2018, 159 cases of high (VZ) and extremely high (VZ) pollution of surface waters were recorded on 15 large watercourses (Table 2), of which 137 cases were observed during the closed channel period, when the rivers are fed only by groundwater, which leads to a violation of the oxygen regime and a slowdown in the rate of chemical reactions. The remaining 22 cases were recorded during the onset of floods (washout of pollutants from the adjacent territory) and before freeze-up (lowering of water temperature). Heavy metals account for about 61% of the total number of IZ + EVD cases, while dissolved oxygen accounts for 37% (Figure 3).

table 2

List of watercourses with incidents of IZ and EWZ in 2010-2017

	Number of cases	Hydrochemical post
		Oktyabrskoe (33), Surgut (7), Sytomino (5), Nizhnevartovsk (6), Polnovat (1), Nefteyugansk (7), Belogorye (2)
r. North. Sosva		Berezovo (11), Sosva (4)
		Beloyarsky (7), Yuilsk (2)
		Khanty-Mansiysk (11), Gornopravdinsk (2)
		Vykatnoe (3), Urai (12), Bolchary (2)
		Novoagansk (3)
r. Trom-Yugan,		Russian (3)
bolshoy Yugan river
		Laryak (4), Bolshetarkhovo (3)
		Lyantor (2)
		Vykatnoy (1), Bolchary (3), Urai (10)
		Beloyarsky (7)
		Lombovorz

The lack of dissolved oxygen is explained by the low water level during the closed channel period and partial freezing of sections in the absence of the possibility of oxygen saturation of river waters.

High concentrations of dissolved forms of heavy metals, in turn, are associated with a reduced oxygen content - under anaerobic conditions, the rate of oxidation of metal compounds slows down.

Of particular relevance for assessing the ecological situation in the region are the concentrations of oil products and chlorides in surface waters, which characterize man-made flows of pollutants in the areas of oil fields.

In accordance with the requirements approved by the Decree of the Government of the Autonomous Okrug dated December 23, 2011 No. 485-p, surface water sampling to determine oil products and chlorides as priority pollutants is carried out at local monitoring points on a monthly basis, taking into account the hydrological characteristics of water bodies. The annual volume of measurements of oil products in surface waters on the territory of licensed areas is about 9,000 pieces.

According to the results of local monitoring, the share of samples contaminated with oil products tends to decrease from 11% in 2008 to 4.8% in 2018 of the total sample (Figure 4).

Figure 4. Distribution of measurements of petroleum products relative to MPC

In general, for 5 years at the oil fields of the district, the average content of oil products in surface waters varied at the level of 0.026-0.049 mg / dm3, not exceeding the established standard (Table 1).

The content of chlorides in surface waters, as well as in oil products, reflects the degree of technogenic load and compliance with the norms of rational environmental management. About 9,000 measurements of chlorides are carried out annually in surface waters in licensed subsoil areas. At the same time, exceeding the maximum permissible concentration of chlorides is rarely recorded, and the share of samples contaminated with chlorides has not exceeded 0.1-0.8% of the sample since 2008 (Figure 5).

Figure 5. Distribution of chloride measurements relative to MPC

Systematically elevated concentrations of oil products and chlorides at monitoring points of surface waters are noted locally, mainly within the boundaries of long-developed license areas with a high accident rate: Samotlor (north) (18 points) and Samotlor (12 points), Mamontovskoye (16 points), Yuzhno-Surgutskoye (3 points), Pravdinsky (7 points), Yuzhno-Balyksky (4 points), Malo-Balyksky (4 points), Ust-Balyksky (2 points), Vakhsky (9 points) and Sovetsky (8 points).

To improve the environmental situation, under the control of the Ugra Nature Supervision, the environmental protection measures of subsoil users on the territory of the specified license areas were adjusted, in terms of taking operational measures to reduce accidents on pipeline systems; carrying out priority measures for the restoration of contaminated land plots and the submission of reclaimed plots for inspection this year.

Thus, the quality of water in surface water bodies of the Autonomous Okrug is largely explained by the natural origin and seasonal dynamics of compounds of iron, manganese, zinc, copper, and also dissolved oxygen. Monitoring studies of recent years have shown that oil and salt pollution for the region as a whole has stabilized at a relatively low level.

The decrease in oil and salt pollution of surface waters on the territory of the Autonomous Okrug is also confirmed by the results of observations in the sections of Roshydromet. Since 2008, in the main rivers (Ob and Irtysh), there has been a steady tendency to reduce the average annual concentration of oil products to a level not exceeding the MPC; the chloride content is stable at tenths of the MPC.

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