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Gully formation. Environmental problems of agricultural land use Design of the transverse profile of the dam

The design of foundations for construction on frozen soils should be carried out in accordance with SNiP 2.02.04-88 based on the results of special engineering and geocryological surveys, taking into account the design and technological features of the structures being designed.

4.11. Gravity processes on slopes and in pits.

They appear when the adhesion forces between particles, i.e., the strength of the rock, are disrupted in the slope soil mass or in the layered strata. This usually happens when rocks are moistened during or after heavy rainfall. The moving force here is gravitational and the movement of the detached mass of soil goes to the base (level) of erosion (to the base of the slope).

There are screes, rockfalls and landslides.

Loess rocks are characterized by anisotropy of filtration properties. Vertically, it is 5-10 times greater than the horizontal water permeability value. The natural humidity of loess rocks is 10-14%.

The fine fraction of loess rocks is represented by hydromicas, quartz, calcite, and montmorillonite. The remaining clay minerals are of secondary importance.

The main distinguishing property of many loess rocks is their ability to shrink when soaked.

Subsidence soil- soil that, under the influence of external load and its own weight (I type of subsidence) or only from its own weight (P type of subsidence) when soaked with water or other liquid, undergoes vertical deformation (subsidence) and has a relative deformation  s 1 > 0.01. The greatest subsidence is confined to horizons lying directly under modern and buried soils. Subsidence increases in the zone of seasonal freezing and thawing of soils and decreases towards the base of the loess rock layer.

The problem of the genesis of loess has not yet been completely resolved. “Obviously loess rocks, like sandy and clayey rocks, can be of different genesis; they are polygenetic” (E.M. Sergeev).

There are a number of hypotheses and theories of the origin of loess rocks. The most famous are aeolian, proluvial, alluvial, etc. In the geological history of the formation of loess rocks, two main stages are distinguished:

Accumulation of precipitation.
Their transformation during lithification into loess rocks.

As shown scientific developments MSU scientists E.M. Sergeev, A.V. Minervin and others, the decisive role in the acquisition of subsidence by loess rocks of different genesis belongs to seasonal and long-term freezing-thawing and rapid phase transitions of moisture according to the ice-water-steam scheme.

When designing and constructing buildings and structures on loess subsidence soils, according to SNiP, measures must be taken to eliminate the dangerous influence of possible subsidence on their stability, as well as external monitoring of the state of the design position of the objects.

5. Engineering-geological surveys.

5.1. Goals and objectives of the research.

Conducted:

To ensure design various types construction engineering-geological characteristics of construction sites.
During exploration and exploitation of deposits building materials.
To provide data on engineering and geological conditions during reconstruction and other types of construction work in built-up areas.

Main tasks:

Study of geomorphological, geological, hydro geological conditions and modern geological processes.
Determination of strength and deformation properties of soils for calculations of rational types of foundations and structures.
Determination of the distribution of conditions of occurrence, genesis, age, thickness, engineering-geological properties of rocks in the massif and the properties of groundwater associated with them, as well as all types of modern geological and engineering-geological processes and phenomena.

Research results:

Engineering-geological report with an assessment of the geological conditions of construction.
Maps, sections, tables of results of laboratory and field studies of soils - graphs, diagrams, tables, photographs.

5.2. Surveys by type of construction.

Industrial and civil engineering (IGC).

Roads and railways.

Urban planning is carried out in all natural areas in diverse and often complex engineering and geological conditions. Underestimation of one of these factors leads to a reduction in the service life of objects and an increase in the cost of their reconstruction or restoration, and to increased pollution of the geological environment.

Features of engineering geology and urban geoecology include:

Multi-branch construction: civil, industrial, hydraulic, mining, municipal, transport, above-ground, in-depth, underground, i.e. different types impact on the geological environment.

A wide variety of types of structures by weight, size, configuration, structures, operating mode, loads (static, dynamic, variable mode).

Large areas of urban areas where new construction is underway are subject to the complete demolition of old structures or the existing facilities are reconstructed (a new foundation is laid, floors are added, the internal layout, type of roofing, etc. are changed). In this case, the foundation rocks experience not only an increase in loads, but sometimes also a series of cycles of loading and unloading. As a result, soil compaction occurs in the zone of influence of the structure, and some physical and mechanical properties of soil change.

In existing cities, the atmosphere, hydrosphere, relief, vegetation and soil cover (embankments, pruning, planning, etc.) are subject to technogenic changes; and the older the city, the more significant these processes are. Under the influence of dynamic influences from moving vehicles under the roadways, soil compaction occurs to a depth of 1.5-2.0 meters. When water leaks from utility networks, technogenic aquifers are formed.

In many cities (St. Petersburg, Kyiv, Omsk, etc.) construction is carried out on alluvial soils.

With the expansion of urban areas, old landfills, cemeteries, exhausted and still active quarries, and agricultural lands appear within the city, which complicates the geo-ecological situation of the urban area.

The main urban planning document is the city master plan, on the basis of which they develop detailed plans development and planning of individual residential complexes, industrial units, transport and engineering communications. IN master plan the peculiarities of the geological structure of the territory, hydrogeological conditions, engineering-geological and geoecological zoning must be taken into account, taking into account the types and characteristics of man-made load on the geological environment.

6. Applications.

6.1. Literature.

Ananyev V.P., Potapov A.D. Engineering geology - M.: Higher
school, 2000
Goldshein M. N. Mechanical properties of soils. - M.: Stroyizdat, 1979
Geological reference book. In 2 volumes - M., 1973.
GOST 25100-95. Soils. Classification. - M., 1995
Druzhinin M.K. Fundamentals of engineering geology. - M.: Nedra. 1978.
Ivanov M.F. General geology. - M.: graduate School. 1974.
Lomtadze V.D. Engineering geology, engineering geodynamics - Leningrad, 1977.
Maslov N. N. Fundamentals of engineering geologists and soil mechanics. -
M.: Higher School, 1982.
Maslin N. N., Kotov M. F. Engineering geology. - M.: Stroyizdat, 1971.
Peshkovsky L. M., Pereskokova T. M. Engineering geology. - M.: Higher School, 1982.
Sergeev I.M. Engineering geology - M.: Moscow State University Publishing House, 1979.
SNNP II - 02 - 96. Engineering surveys for construction. Basic provisions. - M., 1996.
Handbook of Engineering Geology. - M.: Nedra, 1968.
Handbook of engineering surveys for construction M., 1963.
Chernyshev S. N., Chumachenko A. N., Revels I. L. Problems and exercises in engineering geology. - M.: Higher School, 2001.
Shvenov G.I. Engineering geology - M: Higher School, 1997.
Gorbunova T. A., Kamaev S. G. Elements of soil science and geodynamic processes. Tutorial. – Barnaul: From AltGTU, 2004.

6.2. Questions for repetition and control.

Describe the mutual influence of engineering structures and the geological environment.
Name the main branches of engineering geology.
Give a brief description of geospheres.
For what purposes is the age of rocks determined, what methods exist.
What are minerals and rocks called?
How rocks are divided by genesis.
Formation and occurrence patterns of igneous rocks, their fracturing and construction properties.
Formation and conditions of occurrence of sedimentary rocks, their classification, use in construction.
Metamorphic rocks. Main factors of metamorphism, application in construction.
Basics of soil science.
Processes of the Earth's internal dynamics. Types of tectonic movements.
Types of dislocations, their influence on engineering and geological conditions during construction.
Seismic phenomena, Types of seismic waves and the nature of earthquakes.
Lithospheric plates of the upper shell of the Earth and types of their contacts.
What does hydrogeology study?
Types of water in rocks.
Classification of groundwater.
What does the hydroisohypsum map characterize?
Types of water intakes. Darcy's law.
Name the processes of the external dynamics of the Earth and their influence on the geological environment.
Weathering processes and weathering products. Eluvium.
Geological activity of wind: deflation, correction, transportation and accumulation.
Planar and deep erosion. Gully formation. Elements of a ravine.
Geological activity of the river. Elements of the valley, types of terraces, engineering and geological features during construction.
Describe hazardous geological processes, such as:

Suffusion;
Karst;
Quicksand;

Name the construction features.

Geological activity of lakes and swamps, features of construction in these conditions.
Types of glaciers. Features of construction on moraine deposits.
Mudflows. Areas of occurrence and measures to preserve slopes.
Types of permafrost. Occurrence conditions, hydrogeology and construction features.
Gravitational processes on slopes and pits: screes, collapses, landslides. Origin, movement mechanism, classification, control measures.
Engineering-geological features of loess rocks.
Goals and objectives of engineering-geological surveys.
Surveys by type of construction.
What are engineering-geological and geoecological problems cities.

6.3. Geochronological table.

Era(group)	Period (system)	Epoch (department)	Duration ity, million years	Major geological events
Cenozoic TOZ.	Anthropogenic Quaternary. Q.	Holocene (modern) Q 4 Pleistocene: late(upper)Q 3 middle Q 2 lower (lower) Q 1	g-2	Great Russian Glaciation West Siberian Plain: raising of the Caucasus, Ural, Tien Shan mountains. Formation of modern landscape zones of tundra, steppes, deserts.
	Neogene N.	Pliocene (upper)N 2 Miocene(lower)N	25	Alpine folding and formation of mountains in the Caucasus and Crimea. Neogene - Quaternary volcanism.
	Paleogene R.	Oligocene (upper)P 3 Eocene (middle) P 2 Paleocene (lower) P 1	41	The sea periodically floods Ukraine, the Volga region, Western Siberia. Central Asia.
Meso zois Kaya MZ.	Mel K	Late(upper)K 2 ; early (lower) K 1,	70	Flooding of many areas by the sea.
	Yura J.	Late (upper) J 3 average(medium)J 2 early (lower) J 1	55-58	Folding, volcanism and mountain formation in northeast Asia.
	Trias T	Late (upper) T 3 average(average)T 2 early (lower) T 1	40-45	A significant part of the territory seemed to be dry land.
Paleo zoy Skye	Perm R.	Late(upper)P 2 early (lower) P 1	45-50	Herzen folding. Volcanism, formation of the mountains of the Urals, Altai, Tien Shan. Dry climate in the Urals.
	Carbon S.	Late(upper)C 3 medium (average) C 2 Early (lower) C 1	65-70	The sea floods most of the territory. Formation of coals in the Moscow basin.
	Devon D.	Late(upper)D 3 average(average)D 2 early (lower) D 1	65-70	The sea floods the entire area.
	Sipur S.	late(upper)S 2 early (lower) S 1	30-36	Caledonian folding, volcanism and mountain building in the Sayan Mountains, the sea covers Siberia, Central Asia.
	Ordovic O.	Late(upper)O 3 average(medium)O 2 early (lower) O 1	60-70
	Cambrian €	late(upper)€ 3 average(average)€ 2 early (lower) € 1	70-80
Proterozoic PR.	Early Proterozoic			Folding, volcanism, formation of high ridges in Karelia, Transbaikalia, the Kola Peninsula, Ukraine
	Middle Proterozoic
	Late Proterozoic	Riphean, Vendian
Archean AR.	Archaea AR.

4.6. Earthquake intensity scale (with abbreviations).

Intensity, score	Brief characteristics of earthquakes.
I	Insensible earthquakes. Ground tremors are detected and recorded only by instruments.
II	Barely perceptible earthquakes. Vibrations are felt only by individuals.
III	Mild concussion. Hanging objects can be seen swinging in buildings, and the rattling of dishes can sometimes be heard. The earthquake is felt by many people.
IY	Noticeable earthquake. The ground vibrations are similar to the shaking caused by a heavily loaded truck passing by. In houses you can hear the rattling of glass, dishes, creaking of doors, floors, walls.
Y	Awakening. The earthquake is felt by all people, sleeping people wake up, animals are worried. Hanging objects sway violently, and unstable objects tip over. Small cracks appear in buildings, whitewash and plaster are crumbling.
YI	Fright. People in buildings get scared and run out into the street, animals leave their shelters. Furniture moves out of its place. In damp soils, cracks up to 1 cm wide appear.
YII	Damage to buildings. People have difficulty staying on their feet. There are cases of destruction of buildings made of natural stone (clay and broken brick), cracks appear on roads, and pipeline joints are broken. There are isolated cases of landslides in the mountains and on the banks of rivers and seas.
YIII	Severe damage to buildings. Fright and panic, tree branches break off. Many buildings made of natural stone are being destroyed. Numerous cracks appear in stone houses and plaster crumbles. Monuments and statues move. Cracks in the soil reach several centimeters.
IX	General damage to buildings. General panic. Isolated cases of destruction of brick buildings. Are twisted railway tracks. Cracks in the soil reach 10 cm in width. Waves form on the surface of reservoirs, and floods occur on the plains.
X	General destruction of buildings. Brick buildings are destroyed, serious damage occurs in dams, dams, and bridges. Asphalt road surfaces acquire a wavy surface. Cracks in the soil reach 1 m. Large landslides are observed on the banks of rivers, seas, and mountain slopes. There have been cases of water splashing out in lakes, canals, and rivers.
XI	Catastrophe. Reinforced concrete buildings are damaged. Bridges, dams, and railway tracks are subject to significant destruction. A flat surface becomes wavy. The width of cracks in soils reaches 1 m. Vertical and horizontal movements of rocks occur along the cracks. There are numerous landslides and landslides in the mountains.
XII	Relief changes. Severe damage or destruction of almost all above-ground and underground structures. Cracks in soils are accompanied by significant vertical and horizontal movements. The relief changes due to numerous landslides, landslides, and displacements. Lakes and waterfalls appear, the direction of river beds changes

Agriculture as a factor influencing environment

Agriculture is one of the oldest types of environmental management. Since historical times, methods of cultivating land have been known in Egypt, Central Asia, Mesopotamia, using irrigation systems and canals. Currently, agriculture has become, along with industry, a powerful factor influencing the environment.

The basis of development agriculture is the land fund. Today, environmental problems are increasing in agricultural resource management. Environmental problems in agriculture include:

Chemical soil contamination

Soil erosion

Problems of small rivers

Not only industry, transport, and energy are sources of pollution of the atmosphere, water, and soil with chemical elements. Agriculture can also be such a pollutant. Since 1980, the UN has ranked the threat to wildlife posed by agriculture as one of the four most dangerous. There are two sources that determine agricultural pollution: mineral fertilizers and pesticides.

Mineral fertilizers are applied annually to the fields in order to replenish the chemical elements washed out of the soil. Fertilizers regulate metabolic processes in plants, promote the accumulation of proteins, fats, carbohydrates, and vitamins. Small doses of fertilizers, applied taking into account the characteristics of soils and climatic conditions, help increase crop yields. But very often the rules for applying fertilizers are violated. Systematic application of fertilizers in high doses, poor storage, losses during transportation lead to pollution of the environment, especially water bodies, and have an impact on human health.

For example, with an excessive dose of fertilizer, nitrates may accumulate in plants, large number which gets into food and can cause mild food poisoning.

What is much more dangerous is that nitrates are converted in our bodies into nitrosamines, which can cause cancer.

Phosphorus fertilizers entering water bodies cause them to become overgrown and die.

The question arises whether this means that it is necessary to abandon the use of fertilizers.

There is data on the basis of which we can conclude that the doses of fertilizers applied per 1 hectare of arable land vary greatly across countries. They are the highest in Holland - almost 800 kg per 1 hectare. In recent years, one can see a slight decrease in applied fertilizers; nevertheless, it is impossible to obtain high yields without them. Therefore, in order to reduce the harmful effects mineral fertilizers, you need to follow a number of rules.

1. A clear dosage of application - how much fertilizer needs to be applied to increase the yield, so as not to cause damage to the natural environment.

2. Apply fertilizers directly to the root zone of plants, and do not scatter them throughout the field. With combined application methods, plants absorb only 50% of the applied dose, the rest goes with runoff, ending up in rivers and lakes.

3. Avoid loss of mineral fertilizers during transportation railway, highway, when stored in warehouses.

4. Combinations of mineral fertilizers with high doses of organic fertilizers (manure)

5. Strict adherence to the timing of applying mineral fertilizers to the soil.

Pesticides are the collective name for pesticides used in agriculture to control weeds, pests and diseases of agricultural plants.

On average, 400-500 g of pesticides are consumed annually for each person on Earth, and in Russia and the USA - up to 2 kg.

Typically, pesticides are used to kill a specific pest. But besides it, almost all living things in the vicinity die. Scientists have calculated that in our country, up to 80% of moose, wild boars, and hares die from the use of pesticides in agriculture.

The most dangerous group are organochlorine pesticides and among them DDT.

Pesticides become dangerous when they reach a certain concentration. The danger of contamination by pesticides through food and drinking water exists for the entire population of the Earth. They can accumulate (especially in those countries where they are used in large quantities) in the body tissues of fish, birds, and in the breast milk of women.

Pesticides are unusually resistant to high temperature, moisture, and solar radiation.

DDT is detected in soil 8-12 years after application.

Pesticides are particularly dangerous due to their potential for bioaccumulation, for example when bioaccumulating in the food chain:

Phytoplankton -- zooplankton -- small fish® fish-eating birds.

Organisms at the beginning of the food chain absorb DDT and accumulate it in their tissues, organisms at the next level receive higher doses, accumulate them, etc. As a result, the concentration can increase hundreds of times.

Initially, the accumulation and spread of pesticides is observed within a radius of 10-30 km. This is due to the direction of winds and water flow. But over time (after 10-20 years), a much larger area is affected - river basins, etc. The danger of harmful effects increases due to the fact that no more than 3% reaches the target when used, and more often up to 1%. Everything else is carried out from the fields into the water, air, and soil.

The effectiveness of pesticide use decreases sharply over time, as pests develop immunity to their action.

New types of pesticides are becoming more stable and dangerous. The negative consequences of pesticide use for human health are simply obvious, and their trends are increasing.

Agrochemistry as a science is only 100 years old; during its development, it has accumulated a lot of valuable data on chemical processes in soil and plants, introduced into practice the technology of using fertilizers in agriculture, etc. The founder of Soviet agrochemistry, Academician D. Pryanishnikov, in his works emphasized compliance with environmental standards in applied agrochemistry, but now in many of its areas there is no environmental approach, and only momentary problems of plant protection and stimulation of high yields are being solved. Academician Yagodin believes that today the main task of agrochemistry is managing the cycle and balance of elements in the “soil-plant” system, programming soil fertility and product quality. The problem that has become especially pressing in our time is the content of nitrates in products. The World Health Organization has established that the maximum daily intake of nitrates for one person is 325 mg. Intensive use of inorganic fertilizers in many areas of our country led to the fact that in 1988-1993. There was a sharp jump in the concentration of nitrates in food products supplied to government and market trade. Currently, if more products state farms It is still possible to check and control something, but it is very difficult to check what is grown in your own backyard. Private farms often deliberately exceed the norms for the consumption of chemicals, which provides them with a quick and large harvest. And all this causes irreparable harm to land resources.

An important problem in agriculture is soil erosion.

Land (agricultural) resources - this category of resources includes lands used for agricultural production - arable land, hayfields, pastures. The lands that provide most of the planet's population food products, make up only 13% of the land surface. Throughout human history, there has been a process of increasing the area of land used for growing crops - forests were cleared, wetlands were drained, and deserts were irrigated. But at the same time, people were already losing the agricultural lands they had developed. Before the start of intensive development of agriculture, the area of land suitable for arable land was about 4.5 billion hectares. Currently there are only 2.5 billion hectares. Every year, almost 7 million hectares of arable land are irretrievably lost, which means the loss of the basis of life for 21 million people.

The reduction in agricultural resources is associated with human economic activity and violation of basic rules in farming. The main reasons for the loss of agricultural land include: Erosion, soil salinization as a result economic activity(for example, irrigation), the use of agricultural land for the construction of industry, transport facilities, uncontrolled or excessive use of fertilizers, pesticides, making the land unsuitable for agriculture.

Soil erosion is the most dangerous enemy destroying agricultural land. Nine-tenths of all losses of arable land, including the decline in their fertility, are associated with erosion. Erosion is the process of destruction and demolition soil cover by currents of water or wind. In this regard, a distinction is made between water and wind erosion. Improper farming practices can significantly increase the erosion process. The desire to increase short terms Agricultural production often leads to violations of farming rules, such as failure to rotate crops. For example, you can consider how cultivating the same crop, wheat or corn, on the same field year after year affects soil loss.

With continuous cultivation of wheat, annual soil loss is 10 tons/year, corn - up to 40 tons/year. But if we carry out crop rotation - we alternate crops of corn, wheat, clover, annual soil losses will be reduced to 5 tons / year. Lack of fallowing increases soil erosion. It is known that a fallow field is left without sowing for the entire growing season. At this time, weeds and their seeds are destroyed, moisture and nutrients accumulate.

The reduction of fallow land in the United States in the 1970s, driven by the desire to harvest more wheat for sale, led to a sharp increase in wind erosion. Long-term fertility of the land was sacrificed for short-term profit.

Plowing along the slope leads to meltwater flows in the spring or summer rains washing away the fertile layer. Soil losses increase with increasing steepness, and accordingly destroys the crop. To reduce these losses, it is necessary to plow only across the slope and sharply increase the proportion of annual and perennial grasses in the crop rotation.

Powerful agricultural machinery—tractors, combines, and cars—destroys the soil structure. Their use requires taking into account the characteristics of the cultivated soils and the specifics of farming in a given area. Thus, in the USA, the transition to large equipment led to the destruction of terraces in fields, which were supposed to reduce washout in areas with a slope. Powerful tractors and combines require large fields, so their sizes increase, and the strips separating smaller fields, created to reduce erosion, are eliminated.

Erosion is considered severe when 50 tons of fine earth are washed away per 1 t/ha per year; average from 25 to 50; weak from 12.5 to 25 t/ha a year. There are examples of catastrophic soil loss, which reaches 300-500 t/ha. This is especially typical for countries in the tropical and subtropical zones, where rainfall contributes to washout.

Fertile soils are considered a renewable resource, but the time required for their renewal can be hundreds of years. On the cultivated areas of the globe, billions of tons of soil are lost annually, which exceeds the volume of newly formed soils. Therefore, the main task is to preserve the best agricultural land. The development of new lands that are not so fertile is associated with enormous costs. To stop the erosion process, the following measures must be taken:

Moldboard-free and flat-cut soil tillage

Plowing across slopes

Plow plow cracking and sowing of perennial grasses

Snowmelt regulation

Creation of field-protective, water-regulating and ravine forest belts

Construction of anti-erosion ponds at the tops of ravines that accumulate runoff, earthen ramparts, and drainage ditches.

The structure of the soil is also disrupted as a result of the use of heavy equipment in the fields, which compacts the soil layer with the force of its gravity, disturbing its water regime. Issues related to the preservation of small rivers from depletion and pollution, as well as the protection of the nature of floodplain lands, have recently become of particular relevance. Small rivers include rivers with a length of up to 100 km and a catchment area of up to 2 thousand square meters. km. The role of small rivers in the life of large reservoirs, as well as forestry, agriculture and industry, is enormous. Suffice it to say that the drainage area of small rivers within the Upper and Middle Volga is 1/3 of the total drainage area of the basin. Small rivers account for 90% of the total number of rivers in the zone, and their flow is 40-50% of the total river flow. The larger total volume of water mass brought by small rivers cannot but influence the formation of water quality in large rivers. Small rivers have a huge economic importance as local sources of water supply and areas for mass recreation of the population. Rivers are an important element of natural complexes; they are the “circulatory system” of the landscape. Along small rivers there are floodplain lands, which are part of river valleys. Soils play a very important role in national economy, are the main supplier of hay and pasture feed. Despite great value small rivers, insufficient measures are taken to preserve them, and their condition due to pollution, shallowing and drying out is of great concern. Shallowing of rivers occurs due to both natural and anthropogenic factors. Among the natural causes, climate change and the constantly ongoing natural discharge of water accumulated in the Non-Black Earth Zone during the Ice Age, various tectonic movements (uplift of the Russian Platform) are distinguished. Among the anthropogenic causes, the following are distinguished:

Deforestation is especially dangerous: deforestation in the headwaters and water protection zones

Drainage of swamps and wetlands, floodplain reservoirs. In many areas, less than half of the original swamp area remains.

Plowing of slopes and floodplains, which leads to soil loss and siltation of river beds

Water withdrawal from rivers for irrigation, industrial, domestic and other economic needs. At the same time, abstraction from rivers is carried out without connection with environmental management schemes, and water consumption is often unacceptably high.

Decrease in groundwater reserves as a result of uncontrolled water intake through wells.

The destruction of springs, springs, streams, small rivers and the straightening of their channels during land reclamation, the destruction of dams, carried out without taking into account the protection of nature.

River pollution is of particular concern. The abundance of small enterprises in the forestry, food, light, textile, agricultural and industrial sectors on small rivers with backward water purification technology or without it often leads to their catastrophic pollution, destruction of ecosystems, and the complete death of all living things in the rivers. Excessive load from the small fleet also has a detrimental effect. The waters of polluted rivers cannot be used in industry, agriculture, or for domestic needs.

Livestock complexes built without treatment facilities have recently become a major polluter of rivers. Only environmentally sound placement of ecological complexes and full use of their outflows on agricultural irrigation fields (AIF) will protect the environment from pollution. The ability of a river to fight the pollution that enters it is associated with the self-purifying ability of reservoirs, which is determined by a combination of constantly ongoing physicochemical, biochemical, biological processes leading to the restoration of the natural properties and composition of water in the reservoir. But the ability of rivers to self-purify is not unlimited. The smaller the river, the relatively lower its self-cleaning ability.

In recent years, river valleys have been intensively developed into recreation areas. For example, on the Small Rivers Nizhny Novgorod region There are practically no free places left to accommodate recreation areas. Without taking into account the consequences of disruption of natural systems, the construction of recreation centers, hydraulic construction, and the procurement of gravel, sand and other building materials are sometimes carried out on small rivers. The natural resources of small rivers are very large, but at present they especially need careful treatment, constant attention and care from people, since the ecological systems of small rivers are the most fragile and vulnerable.

Currently, a number of measures have been developed to protect small rivers.

First of all you need to:

1. Conduct afforestation of the sources of all rivers, their banks, slopes, ravines, and ravines, carefully protect springs, springs, streams feeding rivers, and implement anti-erosion measures on a much larger scale. Bedside forest-shrub strips should start from the source and follow the entire length of the rivers along both banks to the mouth. The valleys of the smallest rivers, 3-5 km long, with weakly defined floodplains, should mainly remain under forest, with only some of the widest floodplain areas freed up for feeding grounds. This is a very important condition for optimizing landscapes in general and agricultural landscapes in particular.

2. Stop draining swamps that have water-regulating significance, especially at river sources.

3. Conduct the construction of dams on rivers, ravines, streams and ravines, but without flooding the named lands. It is also necessary to strengthen control over the work (plowing, clearing bushes, drainage, damming of reservoirs, placement of sites for agricultural aviation and fertilizer warehouses) that are carried out in floodplains and along river banks by collective farms and state farms. farms.

4. Stop the narrowing of river channels, which in most cases does not economic effect, but causing irreparable damage to river ecosystems

5. Stop plowing floodplain lands, as well as slope lands subject to erosion, as this causes siltation of rivers and reduces the fertility of floodplain lands

6. Deepen river beds while preserving riparian trees and shrubs

7. Reduce as much as possible the existing unreasonably high consumption of water from small rivers for agricultural needs. For each region, a program of measures for the protection, improvement and integrated use of small rivers must be adopted.

Protecting rivers from pollution is one of the most important national economic tasks. Any existing and potential sources of pollution of large and small rivers must be promptly identified and eliminated. The main role in this is played by basin water inspections and sanitary and epidemiological stations. It is necessary to strengthen control over the sanitary and hygienic condition of all rivers, to limit as much as possible the flow of household and industrial waste into the rivers. waste water and wastewater from livestock farms. Control that garbage dumps are not created along river banks, thereby polluting surface and ground waters. It is also necessary during the construction and operation of reclamation systems that strict adherence to established instructions according to the order of work, which eliminates the possibility of contamination entering water intakes. .

1. Strengthen control over the work of local treatment facilities of enterprises that discharge petroleum products into reservoirs and sewers. Improve the operation of treatment facilities to prevent volley discharges. Bring strict liability to violators of sanitary standards for wastewater discharge

3. Prohibit the construction of sites for automobiles and motorcycles near rivers and floodplain lakes, washing cars in reservoirs, as well as the construction of roads near banks, rivers, and lakes.

To protect rivers from pollution by pesticides, fertilizers, and nutrients, the following is recommended:

1. Protect and restore natural vegetation cover along the surface water runoff depressions. These zones, together with river floodplains, are landscape-geochemical barriers that prevent soil, fertilizers, and pesticides from being washed into rivers.

2. Strictly comply with the norms, terms and technology for the use of fertilizers and pesticides.

3. Prohibit and strictly control the use of aircraft for applying fertilizers in heavily watered areas.

4. Make wider use of granular fertilizers, applying them directly under trees and plants.

6. Organize the storage of pesticides and fertilizers in specially equipped premises. Prohibit the storage of fertilizers in the open air.

7. Prohibit the placement of livestock resting areas on the banks of reservoirs, as well as watering livestock from rivers without specially equipped bridges.

8. Thickets of coastal aquatic plants play a huge role in the self-purification of reservoirs. It is necessary to protect, and where they are disturbed, to restore thickets of reeds, cattails, manna, sedges, burps and other plants along the banks of rivers and lakes, around water intake structures as filtration strips, as well as create similar strips along the path of waste and drainage water discharge

As another necessary measure for the protection of small rivers, it is necessary to declare protected all small clean rivers, which are the most important sources of supplying the population with drinking water.

Another important problem of small rivers is the death of the plant and living world in them; in this regard, it is also necessary to take measures for their protection and restoration.

Floodplain lands with rich water meadows are the “golden” fund of natural forage lands. The grass yield in floodplain meadows is twice as high as in dry lands. The rich floristic composition of water meadows predetermines high quality and nutritional value of the feed obtained from them. Floodplain meadows produce high, stable yields from year to year and have been used by humans as hayfields since ancient times. With the development of agriculture and the growth of cities, certain areas of floodplains began to be plowed up. However, the degree of plowing of floodplain areas remained insignificant. They continued to be dominated by meadows, from which, according to zemstvo records, 2/3 of the total amount of hay was harvested. The predominantly haymaking type of agriculture continued to exist in the first years of Soviet power. In the post-war period, there was a massive plowing of floodplain areas, mainly for sowing potatoes and vegetable crops. The high pace of plowing of floodplain lands was often accompanied by formulaic approaches to floodplain reclamation, carried out without taking into account natural features, which leads to a number of adverse environmental consequences. Thus, as a result of plowing, significant areas of floodplain soils during flood periods are subject to erosion and washout in some areas and drift with fresh alluvium in others. Plowing worsens the properties of floodplain soils; they lose 25-40% of the initial reserves of humus and 15-35% of nitrogen. At the same time, the water-resistant soil structure is destroyed, which leads to compaction of arable horizons and a decrease in water-holding capacity. Plowing disrupts the function of soils as landscape-geochemical barriers. After plowing, as a result of soil being washed away from the surface of the arable land and the destruction of the banks, large amounts of agitated material begin to flow into the rivers, which leads to even greater siltation and pollution of river beds. The reduction in the area of floodplain meadows as a result of their plowing leads to a deterioration in the condition of their remaining part. With heavy overload of pastures with livestock and lack of proper care, flooded meadows begin to degenerate. Their productivity drops sharply. With an increase in weediness in meadows, many valuable species of forage plants fall out of the grass stand. Regulation of river flows negatively affects the condition of large areas of floodplain meadows located below hydroelectric dams.

The task arose of increasing the productivity of floodplain meadows. To solve it, it is simply necessary to comply with a number of norms and rules, such as: compliance with the norms of pasture loads, compliance with the terms of haymaking, sowing seeds of valuable varieties of grass, proper and expedient care of meadows, etc. The implementation of these measures will increase the productivity of floodplain meadows, even in areas with heavily knocked down grass, while maintaining the natural multi-species composition of the grass.

During reclamation work in river floodplains, a fairly large amount of tree and shrub vegetation is usually destroyed. At the same time, tree and shrub vegetation in river floodplains has an important anti-erosion value. By reducing the speed of water during a flood, it thereby reduces its erosive power.

To preserve floodplain lands, it is necessary to carry out a number of measures for their rational use and protection:

The area of arable land in river floodplains should be reduced to a minimum.

It is necessary to prohibit grazing of livestock on floodplain hayfields before haymaking

During radical reclamation of floodplain lands, continuous plowing of floodplains is unacceptable. Planning work on floodplain lands should be sharply limited. It is necessary to carefully approach the drainage of floodplain lands, which often harms these territories and removes them from the rank of highly productive territories. Drainage of floodplain lands should be carried out only by closed drainage with two-way regulation of the water regime. Direct discharge of water into rivers is unacceptable. The use of high doses of mineral fertilizers, especially nitrogenous ones, on floodplain lands should be prohibited. The use of all types of pesticides should be sharply limited. In order to preserve small rivers, it is necessary to prohibit drainage and radical reclamation of narrow floodplains of small rivers up to 10 km long. Taking into account the uniqueness of floodplain landscapes, their important role in the Earth’s biosphere and the need to preserve the gene pool of floodplain flora and fauna, create several floodplain reserves.

Ravine - a steeply sloped valley, often highly branched, formed by temporary water flows. The geological process that determines their development is called gully formation.

The main driving force behind the emergence and development of ravines is water erosion, that is, the erosion and destruction of the earth's surface by flowing water. In contrast to planar washout (erosion), when flowing water washes away the entire surface layer on a slope, during gully formation, mainly linear water erosion acts, i.e., erosion and destruction occur along the line of maximum slope of the slope surface.

Stages of ravine development: erosion furrow - pothole(depth up to 1 m, length 5-20 m) - ravine - ravine.

The length of ravines can reach several kilometers, depth - up to 40-50 m (in the loess layer up to 80-100 m), and width 150-300 m. The speed of development of a ravine is determined by the erosion of rocks and can range from 0.3-0.8 m up to 10-20 m/year.

Gully formation is extremely widespread in the steppe and forest-steppe zones of our country (Central Russian, Upper Volga, Volga, Azov uplands, steppe regions of Altai and Eastern Siberia, etc.).

The ravines complicate the construction development of the territory. By dismembering the terrain, they pose a great threat to settlements, road and other engineering structures. In a number of regions of the Central Black Earth region of the European part of Russia, almost a quarter of the total land area is occupied by waste land, occupied by active ravines. Gully erosion is a typical process leading to local loss of resource in geological space with all the ensuing consequences (V.T. Trofimov and D.G. Ziling, 2002).

The main conditions for the development of ravines: 1) the presence of easily eroded rocks (sandy loam, loam, especially loess, to a lesser extent - silty sand, clay, chalk deposits, etc.); 2) rainfall, rapid spring snowmelt, unorganized discharge of technogenic and irrigation waters; 3) slope steepness is more than 4-8°.

The depth of the ravine is limited by the position erosion basis, i.e., the level mark of the reservoir into which the ravine flows. A decrease in the base of erosion causes increased growth of the ravine and its deepening, which can pose a significant threat to already built structures.

The ravine grows with its top up the slope right up to the watershed line. At the same time, it deepens and expands due to the erosion of the slopes of the ravine and the appearance of side holes. When the ravine reaches the watershed line, and the mouth reaches the base of erosion, the development of the ravine fades. Its bottom is leveling out, the slopes are covered with vegetation. The ravine completely loses its eroding activity and turns into bulk y, a negative form of relief with a flat bottom and gentle turfed slopes.

It is clear that the real danger during construction and other economic development of the territory is represented by existing or growing ravines. Signs of growing ravines are steep exposed slopes, sharply defined edges, a V-shaped transverse profile, side openings, etc.

Measures to combat gully formation are complex in nature and are divided into preventive and active (engineering).

Preventive measures are aimed at preventing the development of gully formation processes. Deforestation, longitudinal plowing of slopes, excessive grazing of livestock, excavation work on slopes, etc. are prohibited.

TO engineering activities This includes the installation of simple hydraulic structures for intercepting and draining surface water flow: upland ditches, water-retaining shafts, runoff sprayers, reinforced concrete drainage trays, etc. A system of dams is erected along the bottom of ravines to dampen the energy of the eroding flow. Areas of active erosion are covered with soil and strengthened with rock fill, concrete slabs, etc., followed by paving with stone.

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