Archive for the ‘106’ Category.

Influence of traditional and perspective fertilizers on the activity of сs137 in drained sod-podzolic soils

М. Tаrariko, G. Lychak

Keywords: dried sod-podzolic soil, grain-potato crop rotation, fertility, humus, phosphorus, potassium, radiocaesium СS137, polymineral fertilizer

Goal. To evaluate the long-term effects of the traditional organo-mineral system of fertilizer of grain and potato crop rotation on the fertility of drained sod-podzolic soils. Determine the influence of fertilizers on the activity of Сs137, in particular, to establish the effectiveness of the application of promising polymineral liquid fertilizer «MacroMic» by its foliar application during vegetation from the point of view of increasing yields and decreasing of Сs137 in the yield of plants.

Methods. Long-term stationary agrotechnical and interim search field experiments and laboratory analyzes (SSTS 4280: 2004, SSTS 4405: 2005, SS 26489 – 85, SSTS ISO 10703–200).

Results. It was established that after 10 years of systematic application of the traditional organo-mineral fertilizer system in the 4-fields grain-potato crop rotation, there was a significant increase in the content of humus, phosphorus and potassium, and significantly decreased the acidity of the drained sod-podzolic soils. Almost 30 years after the Chernobyl catastrophe the level of activity of Сs137 in the soil remained high. One of the main factors determining the mobility of radionuclides is the presence in the soil of organic matter, in particular humus acids, which in large quantities are introduced together with the manure. Humic and fulvic acids are capable of generating complex compounds with radionuclides, which is accompanied by a decrease in the activity of radiocesium. Also, one of the main factors influencing the transition of radiocesium from the soil to plant biomass is the level of plant nutrition by potassium. Under the influence of the complex fertilizer «MacroMic», which contains a significant amount of potassium, the content of this element in grain and straw increased by 14 %. In this case, the tendency to decrease the coefficient of transition of Сs137 from the soil to the plants is observed. The introduction of this fertilizer during vegetation on the leaf surface contributed to a significant increase in the yield of triticale in the version without fertilizers from 1.91 to 2.08 ton per hectar, and against the background of the traditional fertilizer system from 4.40 to 4.60 ton per hectar.

Conclusions. In drained sod-podzolic soils, to effectively block the entry of Сs137 into agricultural products, it is necessary to control their physical and chemical properties in order to support the reaction of a soil solution close to neutral, to use higher doses of organic and potash fertilizers, and to use foliar nutrition during vegetation of cereals with soluble fertilizers, which contain potassium. It is also important to reduce the concentration of radiocesium due to increased productivity of crops, which is most achieved when the traditional organomineral fertilizer system is used, due to a radical improvement of all fertility indexes of drained sod-podzolic soils and reduction of radionuclide activity in it.

Yields of haricot beans depending on soil tillage, mineral fertilizers and row spacing under irrigation

V. Ushkarenko, S. Lavrenko, D. Maksymov

Keywords: haricot bean, grain yield, soil cultivation, fertilizers, row spacing, irrigation

Actuality. Nowadays there is a tendency to change agricultural producers attitude to leguminous crops. First of all it concerns winter pea, chickpea, lentil and haricot. At the moment sown areas under haricot are being expanded mainly at the expense of the private sector. The industrial cultivation is insignificant and does not extend, mainly, because of too little knowledge in haricot cultivation technology elements in different agro-climatic zones.

Lately the works dedicated to different aspects of the haricot cultivation technology have been conducted by Saiko O.Yu., Horova T.K., Cherkasova V.K., Akulenko V.V., Bakhmat M.I., Omae H., Kumar A., Egawa E. Along with this, effect of tillage depth, fertilizers and inter-row spacing on the haricot productivity under conditions of the energy and financial crisis has not been completely studied for the irrigated conditions of the South Steppe Zone of Ukraine, that determined  necessity of the proper studies in the above-mentioned field.

Methods of the studies. The research on the improvement of the elements of the cultivation technology of haricot beans in the south of Ukraine was carried out using a three-factor field experiment on the territory of the agricultural cooperative «Radianska zemlia» in Bilozerskyi district of Kherson region. The field experiments were repeated four times. The location of the variants was carried out using a split plot method with partial randomization.

In the field experiments, the following factors and their variants were  examined:

Factor A — basic soil tillage: tillage of 20-22 cm deep; tillage of 28-30 cm deep.

Factor B – nutrition background: no fertilizer; N45P45; N90P90.

Factor C – the width of row spacing, cm: 15; 30; 45; 60.

The studies were carried out with accordance to the common methodology of the field experiments. Precipitation amounts during vegetation period of the crop were determined by using the rain gauge installed at the research plot.  Temperature, air relative humidity were fixed by using the data of the Kherson regional meteorological station. Crop yields were established by using the method of entire harvesting. Grain yields data were recalculated to the standard moisture of 14% and one hundred percent purity. Yields data were estimated by using the agronomic criteria and statistically processed.

The investigated elements of the cultivation technology of haricot beans when irrigated from the Ingulets main canal, its water belongs to the second quality grade (limited suitability), have a significant effect on the productivity of the crop. On average, in 2014-2016, the grain yields ranged from 1.47 to 3.37 t/ha.

According to the results the cultivation of 28-30 cm deep ensured better conditions for the growth and development of haricot plants, which affected the level of its yield. On average, for the years of the research the implementation of this cultivation ensured the yield increase from 0.02 to 0.08 t/ha compared to the tillage of 20-22 cm deep. But these figures according to the conducted dispersion analysis are within the limits of the error (LSD(P<0.05) for the years of the research was 0,04-0,05 t/ha for factor A).

The tillage of 20-22 cm deep ensured the yield formation of the crop of the varieties without fertilizers, on average, for the years of the research – 1.95 t/ha. The application of nitrogen-phosphorous fertilizers in the amount of 45 kg/ha of the active substance provided increase in the yields of haricot bean grain at the level of 0.41-0.78 t/ha. The increase in twice of the amount of active ingredient did not provide a similar increase in the growth of the grain yield. Under these conditions, the growth compared to non-fertilized variants was 0.54-0.78 t/ha, and compared to the previous variant it was only 6.1%.

The analysis of the long-term data shows that the maximum productivity of haricot plants was fixed when the row width was 45 cm. When the row spacing was between 15 and 45 cm wide the crop yield increased, on average, from 1.79 to 2.97 t/ha when the tillage was 20-22 cm deep and from 1.81 to 3.04 when the tillage was 28-30 cm deep. A further increase in the width of the row spacing to 60 cm led to a significant reduction in the crop yield.

Conclusions. The research conducted with haricot under irrigation with irrigation water of the second quality grade (the Ingulets irrigated area) during 2014-2016 showed that the highest productivity of the plants of 3,37 t/ha is formed when the tillage is 28-30 cm deep, the application of mineral fertilizers with the norm N90P90 and the row width of 45 cm. Taking into account the conducted dispersion data analysis we maintain that the most suitable for the introduction into production will be the following elements of the agro-technological complex of cultivation of the crop, which will include tillage of 20-22 cm deep, the application of mineral fertilizers with the norm N45P45 and sowing with the spacing of 45 cm. These technological elements will provide haricot grain yield of at the level of 3.09 t/ha.

Justification of the resource-saving system of arable farming when providing inter-sectoral optimization of reclamated agro-ecosystems of Polissya

Y.Tarariko

Keywords: Reclaimed agroecosystems of Polissya, simulation modeling, sectoral structure, enterprise, farming system, economic efficiency

Goal. To highlight the peculiarities of the formation of the cycle of organic carbon, nitrogen, phosphorus and potassium in different branch structures of agrarian production and to substantiate of the resource-saving organic farming system, which will ensure reproduction of the fertility of drained sod-podzolic soils. Formation of multisectoral agrarian production allows to achieve a high level of recirculation of biogenic elements, significantly reduce compensatory doses of mineral fertilizers and ensure of no-deficit organic carbon balance. In order to carry an accurate quantitative assessment of these opportunities concerning of diverse agroecosystems in the conditions of the Right Bank Polissya, the research task was to evaluate the cycle of nutrients in different scenarios of the development of a typical agricultural production.

Methods. Stationary agrotechnical experiments, simulation computer modeling,

economic analysis.

Results. Based on the results obtained in the experiments, the following prospective Models LLC «Ukrainian Food Alliance» with the area of ​​arable land of 2850.5 hectares, were considered: №1 « Plants specialization», №2 «Livestock specialization», № 3 «№ 2 + processing and storage », № 4 «№ 3 + biogas equipment», № 5 «Model № 4 + drainage-humidifying system», № 6 «№ 5 + flax», № 7 «№ 6 + 7 thousand hectare of  arable» — extension of arable land to 10 thousand hectares to ensure full loading of flax processing equipment. It is established that of all proposed scenarios of the development of the enterprise only under the conditions of Model № 1 with grain specialization and alienation from the field of all crop production will be formed acutely deficient balance of humus. For the implementation of other variants of the sectoral structure, systematic increase of organic material stocks in the arable layer of soil, will be ensured. Only under the conditions of Model № 1 due to the cultivation of only grain crops and flax is formed a negative balance of nitrogen, therefore it is necessary to add nitrogen fertilizers in the amount of 65 kg per hectare. According to the scenarios of other Models of nitrogen fertilizers there is no need to apply with 40-90 kg per hectare of phosphorus and 70-100 kg per hectare of potassium. That is, the development of livestock husbandry makes it possible to significantly increase the level of recirculation of nutrients. At the same time, one of the main tasks is the development and implementation of an efficient system of production, storage and introduction of organic fertilizers. This situation allows us to move on to the principles of organic farming with the profitability of agrarian production of $ 4-8 thousand per hectar.

Conclusions. Conducted balance studies and highlighted technological aspects of the use of organic fertilizers in the melioration land of the humid zone indicate that the implementation in practice of one of the proposed perspective scenarios of development of enterprise actually refers to the development of bioorganic farming system with a minimum of use of agrochemicals. These aspects are the main factors and preconditions for the high competitiveness of melioration agro-ecosystems of Polissya in the future with the achievement of net profit at the level of $ 8 thousand per hectare.

System optimization of water and energy use in rice irrigation systems on ecological and economic grounds

V. Turchenyuk, N. Frolenkova, A. Rokochynsky

Keywords: system optimization, natural reclamation regime, rice irrigation system, ecological and economic principles

Abstract.

The article solves the problem of increasing the functioning efficiency of rice irrigation systems which are complicated technical and ecology-economical objects, demands complicated and systematic decisions approaches, first of all, their systemic optimization and water — energy usage on ecology-economical basis.

Object of this work is aimed at increasing the general functioning efficiency of rice irrigation systems based on the general theory optimization further development of their water and energy usage on ecology-economical basis.

Research methods. Scientific researches were based on the theoretical and experimental methods and also on the information database embracing the period of 1966-2016. The researches were performed on the Danube Rice Irrigation Systems which are located in the Danube estuary Odessa region.

Research results. On the RIS water and energy usage optimization firstly corresponds to flush water mode or to corresponding filtration parameters using surface flooding. Creation and sustentation of minimum required flushing level on the irrigated saline soils due to watering filtration is the main feature and necessary condition of existing rice irrigation systems functioning efficiency.

As we know, on the RIS there is the functioning connection among its components: effect, mode (regime), technology and construction, the systemic optimization reflects  consequent  justification of the mode optimal parameters, water usage technology, construction’s parameters and its elements.

The above presented ecology-reclamation approach is based on the ecology reliability index, optimal parameters of vertical speed filtration which were determinedin the following way: 6-10 mm/d/n.

Calculations concerning the definition of the optimal technological parameters based on economic criteria of RIS functioning efficiency showed that optimal rice quota  in the crop rotation  equals 50-60% and optimal from the point of view of receiving net profit is 18 th.m3/ha.

Based on the above done research it was determined that the optimal distance between drainage-waste canals and additional closed drain-collectors for the Danube RIS equals 100 m. This distance between drains in comparison to existing 200-500 m, provides creation and sustentation on the rice field flushing water mode (regime) with optimal vertical filtration intensity of 6-10mm/d/n.

Conclusions. It was proved that using systemic optimization gives us possibility to consequent justification of optimal parameters of varied mode (regime), technological and constructive decisions in their relation to current economic and ecological demands in building projects and reconstruction of RIS.

Water quality patterns over the length of the Dnieper river

V.Vyshnevskyi, S.Shevchuk, O.Kravtsova

 Keywords: the Dnieper River, water quality, reservoirs, Bortnitska water treatment station

 Introduction. The Dnieper River is the most important river of Ukraine, the water of which is used for many purposes, in particular, for drinking water supply.  Human activity has an important impact on the Dnieper River, the main factors of which are the regulation of runoff and sewage water. In addition to that, the quality of water depends on some natural factors, among which the water runoff is the most significant one.

Goal. The main goal of the investigation is to determine the main patterns of water quality over the length of the Dnieper River.

Methods. The main sources of data obtaining for this investigation were the results of the monitoring of the State Agency of Water Recourses network. These data were processed using the statistical methods. The main attention was paid to the period of 2012–2017.

Results. The investigated period for water runoff can be divided into 2 parts: one with usual water runoff (2012–2014) and another with insufficient one (2015–2017). The mean solids concentation alongside the Dnieper River during 2012–2017 change from 250 mg/dm3 near the border with Belarus to 320 mg/dm3 near the river mouth. There is reverse dependence of this parameter on the water runoff. The smallest solids content near Kyivska HPP is observed in July, near Kherson in March. Such delay in comparison to natural conditions and data of previous investigation can be explained by existence of reservoirs where the water velocity is very small. Moreover, during the last years with small runoff  the runoff  was less than usually. At the same time the colourity of water alongside the Dnipro river has the tendency to decrease. The chemical oxygen demand in the investigated part of the river doesn’t change essentially but during the year period it changes almost twice. The largest meaning near Kyivska HPP ussually is observed in May–August, on the downstream it happens one or two months later. The important contaminators of the Dnipro river is the Bortnitska water treatment station which is located on the south-eastern suburb of Kyiv. Downstream the water quality is much worse than upstream.

During the whole observation period started in 1993, the water quality hadn’t change essentially.

Conclusions. The data of observations provided by of the State Agency of Water Resourses make it possible to characterize spatio-temporal regularities of water quality alongside the Dnipro river. According to the available data the water quality for some parameters has the tendency to improve and for the others – deteriorating. During the whole observation period, started in 1993, the water quality didn’t change essentially.

Patterns of profile variability of drained peat soil properties

S.Kolomiyets, S.Kika

Keywords: physical and water-physical properties, profile variability, structure of peat pore space

Actuality. The problems of efficient use of drained peat soils are increasingly becoming the focus for meliorators, ecologists and the public in Ukraine. The purpose of the article is the publication of new knowledge on the patterns and mechanism of transformation of physical and water-physical properties of peat soils using new methods of laboratory research that will promote harmonization of productive and ecological functions of drained peatlands.

Research methodology. The research was carried out using six samples of peat soil with unchanged structure, selected from different depths of two soil profiles in the territory of Sarny experimental station. The hydrophysical studies of moisture-holding capacity of samples were conducted using a radial scheme in accordance with the requirements of DSTU ISO 11274. The test algorithm was as follows: saturation of the sample to maximum moisture capacity under vacuum, rapid desorption, equilibrium sorption and re-desorption, determination of the final soil moisture and density, calculations and construction of graphs. The innovation of laboratory research is the determination of a capillary hysteresis loop of moisture-holding capacity, characteristics of peat pore space structure and the calculation of the values ​​of field moisture-holding capacity according to the normalized descriptive kinetic graph.

Results. The quantitative patterns of density decrease with the depth and a rise of maximum moisture-holding capacity (MWHC) and field moisture-holding capacity (FMHC) are established. The values of these parameters for the arable layer are significantly different from the properties of deep horizons. The patterns of the profile variability of parameters are identical for both soil profiles. The most informative indicator was the structure of the pore space of peat soils.

A comparative analysis of the porous space structure of different soil layers suggests that the transformation in soil density and water-physical parameters of MWHC and FMHC in the arable layer occurs due to a decrease in the total pore volume, when the size of the pores is smaller than r <2.5×10-3cm, which are located preferably in undecayed plant residues in accordance with the model of double porosity of peat.

The structure of the pore space of the arable layer indicates the presence of the processes of secondary epigenetic self-organization of decayed organic mass with the formation of the structural macroporosity of the peat soil, which can be purposefully controlled.

Water consumption of highly productive forage crops on drained peat soils of the western part of Ukrainian Polissya

S. Kika

Keywords: drained lands, peat soils, vegetative period, water consumption of forage crops, highly productive forage crops.

By the results of the conducted field researches it is established that barnyard grass, amaranth and fodder beans during the vegetative period use moisture in unequal quantity, and on the volume of their water consumption it is possible to allocate three periods: I – from emergence of shoots prior to intensive growth, II – a phase of intensive accumulation of organic substance and the maximum consumption of moisture, III – from the beginning of aging and withering of leaves. During the first period of growth of culture evaporates moisture a little – 20-30% all used for vegetation, during the second period – 50-60, and at the end of vegetation – 15-20%. The maximum consumption of moisture is noticed during intensive accumulation of organic substance and it is mostly the period for the end of June, within July.
It is established that the specified cultures most intensively consume moisture in phases of inflorescences formation, blossoming and at the beginning of grain maturing (62,5 % of barnyard grass; 57,3 % amaranth and 64,3% fodder beans from all water consumption for vegetation). Quantitatively it averages 45,7, 44,1 and 41,9 mm/decade respectively.
Norms of total seasonal water consumption in two years of researches on the drained peat soils were the following: for barnyard grass – 366 mm, amaranth – 307 mm and fodder beans – 326 mm.

It is established also that the productivity of these cultures, despite adverse climatic conditions of the vegetative periods of both years of researches (late spring frosts, high temperature of air, insufficient quantity of an atmospheric precipitation), was rather high. In particular, against the background of mineral fertilizers application N45P60K120 average yield of vegetative mass of barnyard grass is 59,5 t/hectare, amaranth — 46,0 and fodder beans — 40,5 t/hectare that makes 84,9; 86,8 and 86,9% respectively of indicators of the productivity of these cultures received in normal conditions. It allows concluding about their high adaptation ability to specific soil climatic conditions of the drained peat bogs.

Circuits of hybrid drives of sprinkling machine carts when using alternative energy sources

A.Muzyka, G.Martynyuk, G.Boyko, A.Antonyuk, S.Medved

 Keywords: sprinkling machine, support carts, hydroturbine, hybrid drive, generator, hydromotor

 

Then analysis of the operation of modern multi-bearing sprinkling machines has shown that for irrigation needs and movement of sprinkling technics when in use for watering different types of drives and energy sources are used, in particular diesel fuel and electrical power.

Most sprinkling machines move whren irrigating with the help of electric motors of self-propelled carts, which are supplied by power generators of low power (up to 20 kW), which are driven by a diesel engine, and water to the car is fed from a stationary electrified pumping station.

There is an option for moving sprinkling machines with the help of hydraulic motors mounted on the carts, which are driven by hydraulic fluid supplied to them by a hydraulic pump from a diesel engine drive.

As the electrified pumping stations of irrigation systems were designed for  the pressure of 0.6 … 0.8 MPa at the point of connection of a sprinkling machine, while today the sprinkling machines operate at pressure of 0.3 … 0.4 MPa, that is, there is a  possibility of using the so-called excess pressure of 0.2 … 0,3 MPa for obtaining some additional energy at the place of connection of a sprinkling machine without redesigning and laying additional pipelines or power transmission lines. It is important to direct this extra energy for moving sprinkling machines.

The purpose of the research is to develop the circuits of hybrid drives with the use of alternative energy sources to reduce fuel consumption for irrigation by circular, frontal and frontal-circular sprinkling machines.

Analysis of previous research. In the course of previous research at the Institute of Water Problems and Land Reclamation of NAAS it has been established the possibility of using a full-flow hydro turbine as an energy source to feed the drives of the support carts of a multifunctional sprinkling electrified circular machines. The use of a full-flow hydro turbine, powered by the energy of irrigation water flow, makes it possible to do without a diesel generator, and thus without the fuel burn for its operation. Along with that, the sprinkling machines, whose power is provided only by the energy of irrigation water flow (from the irrigation pipeline), cannot move without performing watering. This is a disadvantage that prevents the implementation of technological regulations for watering by such types of sprinkling machines.

Research results. The results of the calculations of the power required for the movement of circular sprinkling machines of various modifications have shown that the use of excess energy of irrigation water in the pipeline at the input of a sprinkling machine with a hydroturbine drive, as a power source for the electric drive or the hydraulic drive for the movement of support carts, requires an increase in pressure in the irrigation network up to 4 m, and taking into account the possible losses of pressure at the connection points and in view of providing a water energy reserve the increase in pressure should be up to 10 m. In this case, the turbine drive with water consumption from 50 to 100 l / s can provide a power within the range of 4.0 to 8.0 kW.

Based on the results of the calculations, we obtained the initial data for the development of the circuits of hybrid drives of sprinkling machines at existing irrigation systems using alternative energy sources. Also we proposed different circuits of hybrid drives of carts, which can be applied on modern multi-support sprinkling machines.

Conclusions. 1. It has been established that modern sprinkling machines operate at a pressure of 0.3-0.4 MPa, while the existing electrified pump stations are designed for pressure in a closed irrigation network of 0.6-0.8 MPa, which gives the possibility of obtaining additional energy for moving sprinkling machines by means of a hybrid drive.

2. It has been established that a hybrid drive with a flow rate from 50 to 100 l/s can provide a capacity within 4.0-8.0 kW.

3. The turbine capacity for moving a sprinkling machine in length from 200 to 500 m, which should be up to 10 kW, has been grounded.

4. It has been obtained the initial data for the development of circuits of hybrid drives of sprinkling machine at the existing irrigation systems using alternative sources of energy. The flow rate of a sprinkling machine should not be less than 50 l/s and the minimum pressure at the connection point of a sprinkling machine should be 0.48 MPa.

5. The circuits of the hybrid drives of sprinkling machine carts with the use of a full-flow turbine have been developed, which will enable to increase the efficiency of existing irrigation systems by providing the excess energy of water pressure in the pipeline network of existing irrigation systems, as well as to provide energy and material resources savings in the range of 20-30%.

Method of the calculation of vertical drainage with the syphone water intake of infiltration water

P.Khoruzhyi, V.Levytska

Keywords: vertical drainage, well, siphon drainage, water intake collector, , hydraulic supports, infiltration water

The efficiency of the operation of vertical airlift drainage systems of the left bank of the Kakhovsky reservoir, namely the area of the Kamyants’kyi Pid is analyzed. It has been established that airlift drainage systems are not effective due to the constant decrease in well discharge as a result of the colmatation of well filters by flocculates of trivalent iron hydroxide, which is formed as a result of the interaction of air pumped by compressor stations to the wells and local water, which contains colloidal iron bicarbonate as well as due to the low efficiency of airlift plants. It is proposed the measures to increase the efficiency of anti-filtering facilities operation by converting the airlift system for water intake from drainage wells to the siphon system.

The method of calculation of vertical drainage with siphon water disposal system in terms of non-pressure groundwater on the basis of hydraulic, hydrogeological and techno-economic calculations of the joint operation of all interacting structures of the anti-filter protection system is given. Based on the calculation of interacting drainage wells for determining the water flow from each well and reducing the static water level, an algorithm for calculating vertical drainage with a siphon system of water intake has been developed. The algorithm includes nine interconnected blocks and calculations by the formulas of the given method. It has been established that water flow from drainage wells under the siphon method of water intake depends on many factors: depth N, number of interacting wells n, distance between wells l, specific hydraulic resistance A, radius of water intake well r, vacuum head Hvac, filtration coefficient of aquifer layer Kf , radius of depression well pit R, well discharge and many other factors. The optimal parameters of the siphon water intake system are calculated by iterating according to the proposed method.

Evaluation of human pressures on the small river basins in Rivne region

I.Gopchak

 Keywords: river, surface water, river basin, human pressures, classification, evaluation

 Restoration of the natural and ecological balance in water ecosystems of the rivers of Ukraine, creation of the conditions for environmentally safe water use are possible only on the basis of determining their actual ecological status, which will enable to implement water management and ecological zoning of the territory of the country, to develop engineering and organizational principles for solving the problems existing in the river basins.

The purpose of the research is to calculate human pressures and classify the ecological status of the basins of small rivers in Rivne region.

The calculation of human pressures and evaluation of their impact on the ecological systems of the rivers in Rivne region is performed on the basis of the classification (assessment) of the state of basic natural systems (subsystems) — land and water resources, water quality by chemical, toxicological, bacteriological and radiation contamination. This can be done using an ecosystem approach based on a logical-mathematical model of a hierarchical structure, which makes it possible to assess the status of river basins in general and within individual subsystems. It also gives an opportunity to evaluate the effect of changes in some indicators on the state of subsystems and basin ecosystems as a whole.

There is no a small river that would have a «good» ecological status. It can be observed some small changes in 50% of the considered rivers, 10% of them can be considered as those which have satisfactory state, but 40% of them are characterized by bad and very bad state. The states of the basins of the Veselukha, Stubla, Vilya, Virka, Lions Rivers are characterized by minor changes, the Ikva River has a satisfactory state and the Slonivka, Ustya, Zamchysko and Korchik Rivers are in bad and very bad conditions.

Summing up the evaluation of human pressures on the small river basins in Rivne region, it can be stated that the general conditions of the basins are generally satisfactory.

This is confirmed by the results of previous studies on the calculation of human pressures and classification of the ecological states of small river basins performed by such scientists as A.Yatsyk, P.Kovalchuk, A.Chernyavska and M.Budz, which are given in “Anthropogenic factor in the formation of the hydrological regime of small rivers of Western Polissya of Ukraine”.

Despite the complexity of the issue of rationing the human pressures on the river basins, using a logic-mathematical model «Small River Basin» it is possible to gradually approximate the values of pressure for each river, which can provide keeping self-cleaning ability of its ecosystems.