The study analyses application possibilities of filtration and thickening models in evaluation of papermaking suspension drainage rate. The authors proposed their own method to estimate the drainage rate on the basis of an existing Ergun capillary model of liquid flow through a granular material. The proposed model was less sensitive to porosity changes than the Ergun model. An empirical verification proved robustness of the proposed approach. Taking into account discrepancies in the published data concerning how the drainage velocity of papermaking suspension is defined, this study examines which of the commonly applied models matches experimental results the best.

Gravity dewatering of fibrous suspension is one of basic technological operations in paper production process. Although there are numerous methods to determine dewatering of such suspensions, none of them can measure undisturbed flow of removed water. In the paper the idea and design of a new apparatus for the determination of drainage rate of fibrous suspensions is presented. The apparatus differs from other known devices by minimisation of filtrate flow resistance in the outlet part of the equipment. In the second part of the paper measurements of the drainage rate have been presented. The flow resistance of the fluid through the bottom wire screen in the device was determined. The calculated flow resistance will be used in the developed model of dynamic drainage of fibrous suspensions, which will be discussed in our following paper (Przybysz et al., 2014).

In the context of climate change, it is important to minimize the changes that are introduced in the territory adjacent to the object of human economic activity. In some cases, this can be done with the help of drainage-screened modules – an anti-filtration screen that redistributes the zone of influence of the drain placed near it. As a result, the drain regulates to a greater extent the zone of human economic activity (drainage system, tailing dump, populated area, etc.) and to a lesser extent lowers the level of groundwater in the adjacent territory. The use of drainage-screened modules in tailing farms, for the organized storage of mineral waste of enterprises makes it possible to increase the filtration stability of dike, ensuringthe uniform operation of the tailing dams, as well as reliable removal of intercepted groundwater. This is achieved because in the tailing farm the dikes are intensified by drainage-screened modules. Water, filtered through the body of the dike and under it, is intercepted by a drain. A part of the filtration flow, which is not intercepted by the drain, is stopped by the anti-filtration screen.

The European Water Framework Directive can have enormous consequences for agricul-ture in the Netherlands. In parts of the country agriculture should be taken out of production because the nutrient loads to the surface water system are far too high. This doom scenario is of course unde-sired and a number of source-specific and effect-specific measures are necessary. The fate of nutri-ents in the soil is strongly interrelated with its hydrology. Directly, because nutrients are transported by water and the distribution of the residence time of drainage water is a good measure for the time behaviour of the nutrient loads to the surface water system. Longer residence time in the soil means more of nutrients applied by farmers but also a longer recovery period, after applying source-specific measures. In this paper three promising effect-specific hydrological measures are described buffer strips, retention strips, and controlled drainage.

Wetlands play a significant role in agricultural landscape. They are the areas of exception-ally great natural values able to regulate water cycling in river catchments. In many cases they are the basic food source for bred animals.

Large areas of wetlands (c. 4 million ha) have been drained for agricultural purposes in Poland. Nevertheless, there are still numerous natural (or close to natural) wetlands, part of which is protected in nature reserves or national parks.

Having in mind the transformation of agriculture and the need of protecting water resources and natural environment, it is necessary to regulate the principles of utilisation and management of re-claimed wetlands. Water management should be adjusted to the type of an area and to environmental requirements. Regardless of the type and intensity of agricultural use of wetlands one has to aim at limiting rapid outflow of spring thaw and rainfall waters which means the reconstruction and increas-ing of natural retention capacity of the river catchment. It is necessary to provide an appropriate num-ber of water lifting facilities and their proper exploitation in land reclamation objects.

It is as well necessary to create appropriate organizational, legal and financial conditions stimu-lating actions to improve water balance and wetland protection.

The study presents the critical evaluation of existing drainage systems from legal, eco-nomical, environmental and technical viewpoints. Nearly 80% of agricultural land in Lithuania drained by underground drainage systems covers around 3 million hectares. The prevailing large scale drainage systems with a complex of engineering structures such as conducting ditches, drains and collectors, local roads, bridges or farm road-crossings, dikes, dams, water reservoirs, pumping stations for irrigation and for drainage need today an efficient management solution in a new economic situation. The detailed analysis of legal and economic instruments adopted in transferring the management responsibilities of drainage systems to users has been carried out. The study resulted in a number of practical contributions towards the amendments in the Law on Land Reclamation in Lithuania and the establishment of a system of indicators that would allow rationalisation of subsidy allocations for the maintenance and improvement of the drainage systems. These subsidies from the state budget make at the moment the largest share among the investment sources. The financial and in kind contribution of drainage users is permanently increasing as are the allocations of the structural funds for public projects. The EU pre-accession programme SAPARD started in 2000 has supported some investments in rural areas. Unfortunately, it did not support the drainage infrastructure properly. A critical review of previous measures allowed suggesting new actions within the framework of the actual support from EU structural funds.

The aim of study was to investigate the effect of nutrient solution leakage during plant cultivation in greenhouse on soil pollution. Investigations were conducted in horticultural farms in the Wielkopolskie province (Greater Poland), specializing in soilless plant cultivation in greenhouse. In the first farm located on sandy soil tomato has been grown since its establishment (Object A). Prior to the beginning of crop culture soil samples were collected for analyses at every 0.2 m layer, to the depth of one meter. Successive samples were taken also in autumn after the completion of 1, 2, 3 and 7 culture cycles. For comparison, research was also conducted in a greenhouse located on loamy sand/sandy loam soil used for 8 years for tomato culture (Object B). In all these facilities plants in rockwool were grown and the fertigation in an open system was provided. Chemical analyzes showed the dynamics of soil properties changes and vertical distribution of cations and anions within the soil profile. Increased content of almost all nutrients and particularly of S-SO4, P, K, Zn, N-NH4, N-NO3 in the soil profile in object A and S-SO4, K, P, N-NO3 in the soli profile in object B were recorded. The results showed that the degradation rate of the soil environment as a result of open fertigation system application depends primarily on the duration of greenhouse operation. However, explicit changes in the chemical properties of soils were observed already after the first growth cycle. Smaller doses of fertilizers and water, and in consequence reduction of nutrients losses may be achieved by closed fertigation systems.

The last two decades have brought a significant modernization in methods of cultivation in greenhouses. Soilless cultures, isolated from soils, have become a common practice, similarly as fertigation (fertilization + irrigation) installations, although most of them are applied in the open system (with no recirculation), where excess nutrient solution is removed straight to soil. This situation was the reason why it was decided to conduct studies, extended over a period of many years, on the estimation of environmental pollution caused by discharged drainage waters containing mineral fertilizers in economically important cultures in Poland (anthurium, tomato, cucumber). On the basis of the chemical composition of drainage waters and amounts of nutrient solution spillway from culture beds data were estimated concerning pollution of the soil medium by the nutrient solution. The level of pollution was dependent on nutrient requirements of crops and the length of the vegetation period. The highest environmental pollution is caused by intensive tomato growing (in kg·month·ha-1): N-NO3 (up to 245), K (up to 402), Ca (up to 145) and S-SO4 (up to 102). A lesser threat is posed by metal microelements: Fe (up to 2.69), Mn (up to 0.19), Zn (up to 0.52) and Cu (up to 0.09). Lower contamination of the natural environment is generated in cultures with lower nutrient requirements (anthurium) and in the case of culture on organic substrates. With an increase in ecological awareness of producers recirculation systems should be implemented in the production practice, in which drainage waters do not migrate directly to soil, but are repeatedly used to feed crops.

Green roofs play a significant role in sustainable drainage systems. They form absorbent surfaces for rainwater, which they retain with the aid of profile and plants. Such roofs therefore take an active part in improving the climatic conditions of a city and, more broadly, the water balance of urbanized areas. One of the factors influencing the hydrological efficiency of green roofs is the drainage layer. In the article, column studies were carried out under field conditions involving the comparison of the retention abilities of two aggregates serving as the drainage layer of green roofs, i.e. Leca® and quartzite grit. The average retention of the substrate was 48%; for a 5 cm drainage layer of Leca® retention was 57%, for a 10 cm layer of Leca average retention was 61%. For a 5 cm layer of quartzite grit average retention was 50%, for 10 cm layer of quartzite grit 53%. The highest retention was obtained for the column with the substrate and 10-centimeter layer of Leca®. At the same time, it was shown that Leca® is a better retention material than quartzite grit. The initial state of substrate moisture content from a green roof appears to be a significant factor in reducing rainfall runoff from a green roof; the ob-tained values of initial moisture content made for a higher correlation than the antecedent dry weather period.

Agricultural drainage has become a priority in agriculture and the economic development of the state. Algeria has launched several agro-economic projects pertaining to natural resources and human potential for development in agricultur-al areas. Our aim is to model the morphological evolution of open drainage channels, under the influence of sedimentary transport processes. The application of the Hydrologic Engineering Center’s River Analysis System (HEC-RAS) software is to examine two-phase mathematical models. In our case it is the flow and the sedimentary charge along a trapezoidal earth channel of a wetland north east of Algeria. The results of these models were validated by actual data obtained during the observation period from 2017 to 2018, for various rainy events. The solid transport and sedimentation velocity equa-tions of Engelund and Hansen and Van Rijn respectively used by this model, give Nash performance criteria equal to 0.95 and determination coefficient R2 equal to 0.91. On the other hand, the laying of a coarse gravel layer of median diameter of the grains d50% = 60 mm on the bottom of the channels reduces the rate of sedimentation by about 32% over an 11-year pe-riod. This satisfying objective study of the modelling allows to obtain an approach to the renovation and a plan for new design of drainage systems, that participates to the sustainable development in the agricultural field.

The research was carried out on a small (52.8 ha) and shallow (4 m) Lake Track in Olsztyn, exposed to a considerably intense anthropogenic pressure. In the middle 1800s this reservoir was dried out and most of the contiguous land was designated for agricultural purposes. The lake was restored in the mid 1900s. At present, the drainage basin of Lake Track is 216 ha. Urban land comprises the largest portion of this area, i.e. 49.3%, barren land 41.4% and forests 6. I%. The lake receives storm waters but for years it had also received sanitary sewage. The results of this research allowed classifying the lake as nutrient-rich, with fairly advanced eutrophication processes. The waters were characteristic of very high nutrients content, up to 0.75 mg P/dm3 and 3.87 mg N/dm3. The high fertility of Lake Track was additionally confirmed by high BOD, values, i.e. up to 9.5 mg 0/dm3, high chlorophyll content, usually from 30 to 40 mg/m3 but reaching 123 mg/m3, and low water transparency, oscillating between 0.6 and 0.9 m. The reason for the lake's high trophic level was no doubt the excessive loading from the drainage basin. The actual nutrient runoff from the drainage basin to the lake exceeded the critical loads, as defined by Vollenweider. Low quality of the lake's waters and the parallel high external loading indicate that preventive measures should be taken, aimed at reducing the external loading.

CropSyst model can be used as irrigation water management tool to increase wheat productivity with poor quality water. The objective of this study was to calibrate CropSyst model for wheat irrigated with fresh and agricultural drainage water. To do so, three field experiments were conducted during three successive seasons in Nubaria Agricultural Research Station, Egypt representing the newly reclaimed calcareous soils. In the first season the treatments were 100% crop evapotranspiration (ETc) of fresh water (FW) and 100% ETc of agricultural drainage water (DW), while in the second and the third seasons, the treatments were 100% ETc of FW, 100% ETc of DW, 120% ETc of DW and 130% ETc of DW. From these results one can concluded that deducting 5% of the applied water to all treatments reduced yield by 3, 5 and 7% in the first, second and third growing season, respectively as a result of heat stress existed in the 2nd and 3rd seasons during reproductive phase. Furthermore, deducting 5% of the applied water from all treatments in the vegetative phase only resulted in lower yield losses. Thus, using CropSyst model could guide us to when we could reduce the applied irrigation water to wheat to avoid high yield losses.

Polish water resources depend on precipitations, which are variable in time and space. In dry years the water balance is negative in central parts of Poland but sudden thaws and downfalls may result in periodical water excess and dangerous floods almost in the entire country. The retention capacity of artificial reservoirs in Poland permits to store only 6% of the average annual runoff, which is commonly considered insufficient. Another method to increase retention is soil water con-trol. About fifty percent of soils in Poland consist of light and very light sandy soils with low water capacity. Loams and organogenic soils cover approximately 25% and 8.5% area of the country, re-spectively. Almost half of agricultural lands (48%) have relatively good water conditions, but the rest requires soil water control measures. An increase of the soil water content could be achieved by changes of soil properties, water table control and soil water management. Modernization and recon-struction of drainage and irrigation systems, which were built mainly in the period 1960–1980, is needed.

The abundance of water has certainly been a very important resource for the development of the Po Valley and has necessitated, more than once, interventions of regulation and drainage that have contributed strongly to imprint a particular conformation on the land. Already in Roman times there were numerous projects of canalisation and intense and diligent commitment to the maintenance of the canals, used for navigation, for irrigation and for the working of the mills. The need to control the excessive amount of water present was the beginning of the exploitation of this great font of richness that was constantly maintained in subsequent eras. In the early Middle Ages, despite the conditions of political instability and great economic and social difficulty, the function of the canals continued to be of great importance, also because the paths of river communication often substituted land roads, then left abandoned. After the 11th century A.D. the resumption of agricultural activity was conducive to the intense task of land reclamation of the Lombardian countryside and of commitment by the cities to amplify their waterways with the construction of new canals and the improvement of those already existing. The example given by Milan, a city lacking a natural river, that equipped itself with a dense network of canal, used in various ambits of the city life (defence, hygiene, agriculture, transport, milling systems) and for connections with the surrounding territory, can be considered as emblematic. In the surrounding countryside, the activity of the Cistercian monks of Chiaravalle represents one of the situations more indicative of how land reclamation and waterways contributed fundamentally to the organisation of the territory over the span of the ages.

The article discusses the option for the application of the methodology for the solution of boundary value problems on the conformal mapping for the calculation of filtration process in the horizontal systematic drainage, provided that the drain is installed at a different depth. In particular, the case of methods combining fictitious areas and quasiconformal mappings for solving nonlinear boundary conditions problems for calculating filtration regimes in soils with free sections of boundaries (depression curves) and intervals of the “drainage” type. As an example, the authors designed a hydrodynamic flow grid, determined the values of the flows to the drain, established a section line and elicited other process characteristics. The algorithm for the numerical solution of model nonlinear boundary conditions problems of quasiconformal reflection in areas bounded by two equipotential lines and two flow lines, when for one of the sections, the boundary is an unknown (free) curve with fixed and free ends. The conducted numerical calculations prove that the problems and algorithms of their numerical solution, with a relatively small iterations number (k = 141) suggested in the paper, can be applied in the simulation of nonlinear filtration processes that arise in horizontal drainage systems. Total filtration flow obtained Q = 0.9 dm3·s–1; flow for drains Q1 = 0.55 dm3·s–1 and Q2 = 0.35 dm3·s–1 are quite consistent with practically determined values.

The paper concerns the transformation of water resources induced by the construction and functioning of the Brest Fortress defence structure and presents the current water resources resulting from these changes. The study was conducted by analysing historical materials: maps, plans and written documents. Hydrographic changes were analysed for five study periods covering almost 200 years, from 1823, presenting the hydrographic network before the construction of fortifications, up to 2018, when most of these structures ceased or were repurposed. Hydrographic changes were analysed in detail for the area of the Terespol Fortification. The analysis revealed that almost 80% of the wetland area had disappeared after intensive drainage works, and several dozen originally small and isolated areas had been incorporated into a vast drainage network. One of the consequences of these activities was the creation of significantly transformed artificial catchments within the study area.

The objective of the paper was the hydrological analysis, in terms of categorizing main watercourses (based on coupled catchments) and marking areas covered by potential impact of the occurrence and activities of the European beaver Castor fi ber . At the analysed area – the Forest District Głogów Małopolski there is a population of about 200 beavers in that Forest District. Damage inflicted by beavers was detected on 33.0 ha of the Forest District, while in the area of 13.9 ha the damage was small (below 10%). The monitoring of the beavers’ behaviour and the analysis of their influence on hydrology of the area became an important element of using geoinformationtools in the management of forest areas. ArcHydro ArcGIS Esri module was applied, as an integrated set of tools for hydrographical analysis and modelling. Further steps of the procedure are hydrologic analyses such as: marking river networks on the DTM, filling holes, making maps of the flow direction, making the map of the accumulation flow, defining and segmentation of streams, marking elementary basins, marking coupled basins, making dams in the places, where beavers occur and localization of the area with a visible impact of damming. The result of the study includes maps prepared for the Forest District: the map of main rivers and their basins, categories of watercourses and compartments particularly threatened by beaver’s foraging.

The situation when groundwater considerably rises above the “normal” level, water intake, lowering of groundwater levels and other relevant practical tasks require the drainage facilities. The most effective techniques of numerical studies of the corresponding boundary problems at present time are methods of dealing with inverse boundary value problems (conformal and quasi-conformal mappings). As basis of this research we used the case of combining the fictitious domain methods with quasi-conformal mappings of the solution of nonlinear boundary value problems for the calculation of filtra-tion regimes in environments with free boundary areas (depression curves) and zones of “mountainous” areas. This paper reviews the stationary issue of flat-vertical stationary non-pressure liquid filtration to horizontal symmetric drainage. In the paper a practical methodology for solving boundary value problems on conformal mappings is suggested for the calculation of the filtration process in the horizontal symmetrical drainage. The idea of block iterative methods was used during the creation of the corresponding algorithm which is based on the alternating “freeze” of the anticipated conformance parameter, the internal and boundary connections of the curvilinear area. The results of the conducted numerical calculations confirmed the effectiveness of the suggested problem formulations and algorithms of their numerical solution and the possibility of their use in the modelling of nonlinear filtration processesoccurring in horizontal drainage systems, as well as in the design of drainage facilities and optimizing other hydrosystems. Therefore these results are of great importance.

The goal of the presented research works is to prove the following thesis: Does the process of contaminants reduction and effiuent application for arable land fertilization justify the treatment method of waste water from a yeast production facility in soil and plant environment. In order to achieve the above mentioned goal, basically the dynamics of physical and chemical properties change observed for waters, soils and plants irrigated with wastewater from yeast factory has been studied for many years. Part I presented the problems characteristics of production as well as water and wastewater management in the yeast factory, principles and technological effectiveness of the treatment of process wastewater from yeast production in soil - plant environment and impact of irrigation with wastewater on water purity. The research proved that very high biological treatment indices are achieved on the Silesian Yeast Factory fields where process wastewater is utilized i.e. concentration reduction for: BOD5 - 99.3% and COD - 99.7%, - for eutrophic compounds: N,0,.1 - 98.83%, P - 96.25% and K - 99.18%. The obtained percentage of concentration reduction is higher than the standards assumed in the water supply and wastewater discharge consent issued to the factory. The drainage water from the fields irrigated with yeast effluent is of I, II and III class of purity.

Green roofs are increasingly popular in both new and modernised buildings. They significantly reduce the outflow of stormwater from buildings and change its composition. Wherever an urbanised area is equipped with a separate sewage system, usually stormwater goes directly to the receiver without treatment, which may affect the quality of water in the receiver. The article presents results of research carried out on the green roof of a building in Lodz, Poland. During rainfall, the flow rate from the roof was measured. With the use of the US EPA software Stormwater Management Model (SWMM) a model of the green roof was created and calibrated using rainfall data from the city’s pluviometric network. Based on the measurements of the roof runoff, as well as SWMM modelling, the degree of outfall reduction was determined. Samples of roof runoff were collected to study the characteristics of rainwater, including pH, electrical conductivity, organic compounds, nitrogen, phosphorus, and suspended solids. The results were compared with the quality of runoff from a traditional roof. Except ammonium nitrogen, values of the examined quality indicators was higher in the case of the green roof but the pollution load of almost all contaminants, except phosphorus, were lower due to a significant reduction in the volume of stormwater outflow (62–91%). The quality of stormwater discharged from the green roof improved with its age.

Flooding in the northern part of The Netherlands has caused serious economic threats to densely populated areas. Therefore a project has been carried out in a pilot area to assess the retention of water in two river basins as a way to reduce flooding. The physically-based groundwater and sur-face water model SIMGRO was used to model the hydrology of the basins. The model was calibrated using discharges and groundwater levels. Scenarios of measures to assess the possibility of retaining water in the basin were then defined and tested. The first measure was the retention of higher dis-charges using culverts or gates in the upstream part of the basin. The second measure was to make the streams shallower and thereby, increase flood plain storage. The last measure was flood water storage in a designated area in the downstream part of one basin. The analysis indicates that holding water in the upstream parts of the basins proved to be feasible and can result in significant reductions of peak flows.