The purpose. To determine basic water-environmental problems of rivers of Western Polissia of Ukraine (on an instance of water-collecting area Horyn). Methods. Dialectic method of scientific knowledge, analysis and synthesis, system generalization. Results. State-of-the-art ecological state of basin of the river Horyn is characterized. Basic water-environmental problems in water-collecting area are analyzed, in particular water deliveries of the population and branches of national economy, complex geological structure of water-collecting area, provision of water service of Khmelnytskyi atomic power plant, reclamative land development, water pollution, etc. Is established that for today water-ecological situation in basin of river Horyn is catastrophic, that influences all the sides of vital activity of the person and leads to significant ecological and economic losses. Owing to breaking the water balance river Horyn shallows. The major factors influencing deterioration of surface and subsoil waters in water-collecting area, are disposals of sewage. Except for pollution of water objects, the urgent problem demanding the solution is the acting structure of lands in the basin of river Horyn. As a result of excessive agricultural land use the areas of natural lands were sharply divided out. Conclusions. By results of the analysis of water-environmental problems in the basin of river Horyn it is established that a priority task for solving crisis situation is execution of complex assessment on transformation of ecosystem of the river with the subsequent development of nature protection measures. The solution of the given problems depends first of all on perfecting rational water management in water-collecting area on the basis of implementation of basin principle of water resources management.

The purpose. To assess modern ecological state of small rivers of Western Polissia of Ukraine (on an instance of rivers Luga and Ghapa). Methods. Research was carried out according to regular observation on the basis of ecological classification of quality of surface waters of land and firths of Ukraine which includes a panel of hydrophysical, hydrochemical, hydrobiological and other parameters reflecting features of components of aquatic ecosystems. Results. Analysis of modern ecological state of small rivers of Western Polissia of Ukraine was carried out, and also assessment of quality of their waters on conforming classes is made. Findings of investigation were grouped in 3 blocks of parameters: salt compound of water, trophic-saprobiological (ecologicalsanitary) block, specific matters of toxic effect. Integrated (ecological) index is determined, which values establish class and category of quality of surface waters. Results of observation over quality of surface waters of rivers Luga and Ghapa testifies to their satisfactory state. Surface waters match to IInd class of quality of water (river Lugawaters, transient on quality from "very good" up to "good", from "clean" up to «enough clean» on purity; river Ghapa -waters with a trend from "good" up to "satisfactory" on quality, from «enough clean» up to "poorly polluted" on purity). Excess of maximum-permissible concentration is fixed according to trophic-saprobiological parameters. It is caused by high anthropogenic load in basins of the rivers, first of all, waste interceptions of not enough cleaned waste waters. Conclusions. For assessment of ecological situation of water objects of Western Polissia and determination of main directions of water-security activity on improvement of ecological state of each water object the great value has water quality assessment of small rivers.

The purpose. To execute zoning of territory of Western Polissia of Ukraine on anthropogenic load and to evaluate ecological state of basins of small rivers. Methods. Study was conducted according to regular observation within the limits of basins of the probed rivers with the use of system model of hierarchical structure «Basin of small river». The given model realized grading basins of small rivers on extent of anthropogenic loads and allowed tracking state of water-collecting area on various indexes in a slit of separate subsystems (radioactive impurity of territory, use of lands, use of river flow, quality of water). Results. At account of extent of anthropogenic load on basin of small rivers they evaluated quantitative and quality indicators of separate subsystems. It was established that on aggregate of all criteria the ecological state of basins in 33% of rivers was characterized as «changes negligible», 25 -state «satisfactory», in 42% -state «bad» and «very bad». General ecological state of basins of small rivers of Western Polissia was unsatisfactory. By results of water-ecological zoning of territory of probes they offered some nature protection measures. In particular, in all basins of rivers of Western Polissia first of all it is necessary to increase amount of forests, to diminish the areas of agricultural lands and index ploughing. Conclusions. With the purpose of martempering and restoring of the disturbed natural state of basins of small rivers of Western Polissia of Ukraine it is necessary to hold water-ecological zoning of their territories. That will promote density of force of all objects of control and managing for development and implementation of general basin and territorial nature protection measures.

The purpose. To determine ecologically admissible volumes of take-off of water from small rivers. Methods. Research is lead according to regular supervision over small rivers of Prypiat Polissia of Ukraine. At assessment of ecologically admissible volumes of take-off of water from the rivers the basic condition is preservation of ecologically safe condition of water eco-system at which changes of its structurally-functional organization do not harm to ability of natural complexes to self-control, to autopurification and selfrestoration. Results. Ecologically admissible volume is determined of take-off of water that enables to carry out take-off of water from rivers for various economic needs without damage of water eco-system. It is established that under the influence of anthropogenic load water eco-systems for last years have undergone essential changes. In particular significant transformations of water-intaking area and big regulation of drain are observed. Ecologically admissible volumes are determined of water take-off from rivers for the long-term period in years with different security (50, 75, 95 %), and assessment of ecologically admissible volume of take-off of drain under condition of preservation river eco-system is carried out. Calculations have shown that in very shallow year (Р=95 %) water resources do not provide volumes of ecological drain, and in shallow year (Р=75 %) its water resources slightly exceed ecological drain. The volume of ecological drain almost at half of researched rivers reaches 40%, and in others -50 -60% of norm of drain. Conclusions. It is established that in Prypiat Polissia of Ukraine in very shallow years for water-economic needs is necessary to use stocks of other water resources. The further calculations of ecologically admissible minimal volumes of water should be complex and consider as much as possible criteria of condition of river that will enable to reveal such criteria which worst of all influence its condition.