This study is aimed at evaluating the applicability of Artificial Neural Network (ANN) model technique for river discharge forecasting. Feed-forward multilayer perceptron neural network trained with back-propagation algorithm was employed for model development. Hydro-meteorological data for the Imo River watershed, that was collected from the Anambra-Imo River Basin Development Authority, Owerri – Imo State, South-East, Nigeria, was used to train, validate and test the model. Coefficients of determination results are 0.91, 0.91 and 0.93 for training, validation and testing periodsrespectively. River discharge forecasts were fitted against actual discharge data for one to five lead days. Model results gave R2 values of 0.95, 0.95, 0.92, 0.96 and 0.94 for first, second, third, fourth, and fifth lead days of forecasts, respectively. It was generally observed that the R2 values decreased with increase in lead days for the model. Generally, this tech-nique proved to be effective in river discharge modelling for flood forecasting for shorter lead-day times, especially in areas with limited data sets.

Scarcity of fresh water resources is the major constraint for agricultural development in Iran as in many other regions with arid and semi-arid climate. With the pressure on fresh water resources, the use of un-conventional water resources including brackish, saline and sewage water has received greater attentions in recent years. The objective of this study was to assess the impact of farmers' practices using saline groundwater on wheat yield and soil salinity in a Mediterranean cli-mate of Fars province in southern Iran. The study was carried out in several commercial wheat production regions for two years. Chemical analysis of irrigation waters, volume of applied irrigation water, electrical conductivity of soil saturation extract (ECe) and yield were measured in each field. General information on agronomic practices was also collected using a questionnaire. Results demonstrate that waters with salinities higher than what has been classified as “suitable for irriga-tion” are being used for the production of wheat crop. Analysis of wheat yield response to saline irrigation water showed that for water salinities up to 10.7 mS∙cm–1 (threshold value) variation in yield was relatively minor, above which wheat yield decreased at a greater rate. Root zone salinity profiles showed the effect of winter rainfall in reducing soil salinity. It is concluded that although acceptable yields are obtained with some of the highly brackish waters, over application of these waters would threaten the sustainability of crop production in the region.

The present study tries to quantify soil losses using Geographic Information Systems (GIS) and analytic hierarchy pro-cess (AHP) in the Medjerda watershed (Algerian-Tunisian border). The Analytic Hierarchy Process (AHP) method is used in the quantification of erosion qualitative characteristics, through its weighting. It is used for many problems requiring decision-making. This catchment area is characterized by moderately consistent lithology, irregular rainfall, medium slope and low vegetation cover, which makes it very sensitive to erosion. Therefore we claim to develop a spatialization map of vulnerable areas, based on analytic hierarchy process and GIS that define the combination of specific factors. The integration of the thematic maps of the various factors makes it possible to identify the impact of each factor in the erosion, to classify the sensitive zones, and to quantify the soil losses in the basin. This mapping will be an important tool for land use planning and risk management. From the distribution map of erosive hazards, we have identified four classes of vulnerabil-ity, areas with very high to high vulnerability are mainly in the northern part of the watershed (where the relief is very important).

This study presents the hydrochemical composition of groundwater under long-term irrigation of Wonji plain (Ethiopia) and its quality status for drinking purpose. Groundwater samples were collected from 30 groundwater monitoring tube wells installed at different parts of the sugarcane plantation and then analysed for the major physico-chemical quality parameters (pH, EC, major cations and anions) following standard test procedures. The status of groundwater for drinking was compared with WHO and other quality standards. Analytical analysis results indicated that majority of the considered quality parameters are rated above the prescribed tolerable limits for drinking set by WHO. About 97% of the water sample has water quality index in the range of very poor to unfit for drinking. The contamination index is in the ranges of low (–1.0) to high (3.6). In general, the groundwater of the area is unsuitable for human consumption without proper treatment such as boiling, chlorination, filtering, distillation, desalinaization, defluoridation, deionization, demineralization (ionexchange) and membrane processes. Since the TDS concentration is relatively small (<2000 ppm), demineralization process alone can be sufficient to bring the water to an acceptable level.

For the last few decades there have been reports not only of the occurrence of new invasive species of European water-courses, but also their increasing expansion. One of such species is the Amur sleeper (Perccottus glenii). The present work contains assessment of age and length distribution, condition as well as growth rate and analysis of the parasite fauna of theAmur sleeper from the waters of the Vistula River tributary in its middle course (the Habdziński Canal). During the catch performed in 2017 and 2019, the total of 177 Amur sleepers were recorded in the studied watercourse and a statistically significant sex structure disproportion was observed. Among the specimens caught in 2017 dominant were fishes with lengths of 50.1–60.1 mm whereas in 2019 the majority of the Amur sleeper specimens measured 30.1–50.0 mm.Six age groups were recorded among the caught fish with a clear prevalence of specimens aged 1+ (70.06%). The most frequently recorded parasite of P. glenii was non-quantifiable Trichodina rostrata ciliate for which the Amur sleeper from the Polish waters appeared to be a new host. Moreover, the presence of an acanthocephalan Acanthocephalus lucii, not recorded in Poland in this host before, was observed in the chyme. Also, accidental presence of larvae of the Opisthioglyphe ranae tre-madote, which is a parasite typical of amphibians, was also recorded. Despite unfavourable habitat conditions and in-creased volumes of biogenic substances in the waters of the Habdziński Canal, the Amur sleeper found convenient condi-tions to reside in this small watercourse.

Reservoirs have a very important function in providing multi-sector water requirements. In the future, reservoirs not only serve to store and available water can also be used as disaster mitigation instruments. The completeness of hydrological measurements in reservoirs can be expanded more widely for climate change mitigation. The reliability of the reservoir capacity varies greatly depending on the El-Nino character that occurs among them El-Nino is weak, moderate, strong and very strong. The El-Nino characteristic is very influential on the period of water availability, the increase of evaporation capacity and decrease of reservoir capacity. Analysis of the reliability of the reservoir volume due to El-Nino using the Weibull equation. The deficit reservoir was calculated using the concept of water balance in the reservoir that is the relationship between inflow, outflow, and change of storage at the same time. Based on the results of the analysis showed that the evaporation increase and the decrease of reservoir capacity had a different pattern that is when the evaporation capacity started to increase at the same time the reservoir capacity decreased significantly. The correlation coefficient between evaporation capacity increase and decrease of reservoir water capacity are consecutively –0.828, –0.636, and –0.777 for El- Nino weak, moderate and very strong respectively. At the reservoir capacity reliability of 50% reservoir has a significant deficit. When weak El-Nino the deficit is 2.30∙106 m3, moderate: 6.58∙106 m3, and very strong 8.85∙106 m3.

The unique oasis of Zousfana, on the western edge of the Grand Erg Occidental, Taghit is the pearl of the oases of Saoura, a palm grove of 180 ha over an 18 km length crossed by Oued Zouzfana. It regroups the different types of landscapes of an arid zone (erg, hamada, barga – a small hill, oued ...). Taghit is known for its hydraulic civilization, the oasis in its hostile environment has survived thanks to the exploitation of rare groundwater irrigation according to the traditional customs applied to the whole of society. The peasants spur out the water resources through foggaras and traditional wells. But the intervention of modern irrigation techniques in an anarchic way has disrupted the fragile mode of irrigation and the abandonment of the palm grove. The over-exploitation of groundwater by the use of boreholes and motor pumps leads to the drying up of water sources, mists and traditional wells. Today, only 45 000 palm trees are productive and less than 1500 fruit trees. There are 500 fellahs in the entire agricultural area of Taghit, the majority of them is fleeing work in the oasis because of the lack of income from it. When comparing the results of analyses from different campaigns (2015 and 2008), a spectacular increase in the salt concentrations in the groundwater of the different palm groves is noticed. According to our investigations, the main causes of this jump are: the overexploitation of the water tables by motor pumps, the abandonment of land inside the palm grove, the lack of maintenance of the gardens, the exploitation of domestic wastewater in the irrigation. According to this preliminary study, it is important for the State to make farmers aware of the role of their traditional irrigation systems in the continuity of the oasis and life in it.

Modern technologies make it possible to obtain a lot of diverse information about the soil properties using satellite images, but field studies are also required to create or refine digital soil maps. To create a digital soil map scaled 1:25 000 in 2016, a classical field study was conducted with the laying of soil sections in places with the same coordinates as in the mapping of 1982. It allowed to carry out retrospective monitoring of transformation of morphogenetic and agrochemical properties of soils of the southern forest-steppe of the Republic of Bashkortostan (Russia) for the 34-year period of farm use. Thus, the correction and digitization of the soil map allowed to establish that arable land occupies 69.792 ha (67.9%) in the structure of agricultural land (102 811 ha). The monitoring showed deterioration of the main characteristics of arable soil fertility: the diminishing of humus-accumulative horizons, significant decrease of humus content (p ≤ 0.05), a small but reliable acidification of the medium reaction and reducing labile phosphorus. Losses of organic matter occurred mainly in the most fertile soils; their proportion decreased from 55.9% of the total area of agricultural land to 12.4%.

Since the beginning of the 21st century floating buildings have been growing in popularity in Poland. According to market research and quantitative studies, the majority of operative Polish floating buildings serve for commercial purposes, such as short-term rentals, vacation houses and floating marinas. Simultaneously, despite the increasing demand, the development of floating buildings in Poland is limited by the inconsistent legislation, government policy and, most importantly, natural conditions of Polish inland waters. The most attractive sites for floating architecture are the semi-natural lakeshores and riverbanks. At the same time, low water levels and poor maintenance of many Polish basins require special architectural and engineering solutions. The article presents our experience with meeting the market’s demand for small cost-effective floating commercial buildings despite the local shortcomings of inland waters on the example of the floating apartment built in 2019 on the Roś Lake in Pisz, Poland. The presented building was intended as a water-based extension of the existing hotel on land. It was designed as a “modern barn” with all-glazed gable wall allowing for a spectacular view to the lake. With a 50 sqm footprint, the one-story house with a mezzanine has a small draft of 33 cm and meets the stability criteria defined for inland waters. The presented case study shows that integrating the naval architecture theory, Building Information Modeling simulation along with cutting-edge construction techniques such as Scottsdale Construction System (SCS) and polyurethane spray insulation, can bring significant progress into the development of the floating buildings market in Poland.

The ground source of drinking water for the village of Skalice nad Svitavou is located 35 km North of Brno (Czech Republic). An evaluation of developments in selected indicators of water quality in this groundwater source in the period 2013–2017 was the essence of this work. The data was provided by Vodárenská akciová společnost, a.s., i.e. the operator. At the same time, annual monitoring of water quality in the Úmoří stream, which flows through the catchment area and can affect the quality of groundwater, was carried out. Water samples were collected in 2017–2018 from 6 profiles on the Úmoří stream and its two tributaries. Raw water from the groundwater source does not meet the requirements for drinking water in some indicators and needs to be treated. Monitoring of surface water shows that the most problematic indicator is total phosphorus, the concentration of which exceeded limit values on all sampling profiles. The highest values were found in the tributaries, where total phosphorus concentrations exceeded 10 mg∙dm–3. There are 12 municipalities in the area of interest, only two of which have their own sewage treatment plant. It is clear from the results that wastewater in some municipalities is discharged directly into the recipient and is the cause of above-limit concentrations of both phosphorus and nitrogen. Intensively used agricultural land is another major source of pollution. Based on an analysis of sources of pollution, corrective measures have been proposed to improve the quality of surface and groundwater in the area.

In this paper, finite element modelling is employed for simulating and analysing seepage and slope stability of earthfill dam via GeoStudio software. Two products are employed, which are SLOPE/W for slope stability and SEEP/W for seepage analysis. The behaviour of earthfill dam with four different types of sandy soils having different values of hydraulic conductivity (K) has been studied. Different upstream (US) slopes of 1:2, 1:2.5, 1:3 and 1:3.5 for the earthfill dam are simulated. The downstream (DS) slope is constant at 1:2. The results showed for all the four types of soils that when the US slope is increased, the amount of seepage from the dam increases and the factor of safety (F) decreases. For each US slope, when K (type of soil) increases, both seepage and F increase. Fine sand soil is associated with less seepage and less F. Sixteen equations are obtained to predict both seepage and F with respect to US slope for each type of soil and K of the soil for US slope. An experimental model for earthfill dam is constructed in the laboratory of hydraulics, Benha University to investigate the seepage of water through earthfill dams. It is concluded that seepage decreased when K decreased, and when the US slope for each type of soil decreased. The seepage increased when K increased for each US slope. Seven equations are obtained to predict seepage with respect to US slope for each type of soil, and K for each US slope.

A failure analysis of Babar dam on the El Arab River was performed to highlight the impact of flood wave and velocities on the four villages downstream of the dam; Hella, Khérenne, Chebla and El Oueldja. The simulation of wave propagation along the El Arab River under several scenarios was performed by the hydraulic HEC-RAS model. This model is dedicated to the description of floods at the dam following a breach in the dike. The main factors considered in this simulation include the level of flood water, the flood hydrograph, and the typical scenario for this breach. The flood risk analysis revealed that the maximum of flood wave flow registered at the breach is (Qmax = 9253.02 m3∙s–1), and is beginning to mitigate downstream of the dam along the El Arab River where it reached at the last village with a low flow (Q = 1110.64 m3∙s–1). This simulation allowed drawing the risk map which showed the areas threatened by flood wave resulting from a total failure of the work, and consequently required a plan of security measures to moderate as much as possible the consequences of floods. A sensitivity analysis was conducted to approach the parameters of impact of the breach on the dam failure scenario. It was confirmed that these parameters as formulation time, breach width and side slope have a great influence on the dam failure scenario with the four adjustments (±20 and ±50).

The results of a research into the scale and consequences of the degradation of aquatic ecosystems in Ukrainian Polesie have been detected in article, and the areas of increased anthropogenic pressure have been identified which greatly affect the condition and number of aquatic macrophytes. The biodiversity of sites with different anthropogenic load was evaluated using the biodiversity criteria. In the research, the structural and functional features of macrophytic species diversity within Teteriv River ecological corridor as a typical river landscape of Ukrainian Polesie were determined and described, the floristic composition was determined. Within the ecological zones, the number of species and their projective coverage in areas with different anthropogenic pressures within Teteriv River ecological corridor were determined. The basic criteria for the implementation of deferred biomonitoring based on the analysis of the dynamics of the spe-cies composition of the phytocoenoses of Teteriv River ecological corridor on the indicators of ecological stability and plasticity using the species-specific criteria, are: Margalef species richness index, Sørensen–Dice index, Shannon diversity index, Simpson’s index, and Pielou’s evenness index. Based on the results, correlation dependencies have been constructed, which will allow to obtain data on the stability of the development of aquatic ecosystems according to the data of species surveys. Interconnections between biodiversity indicators and indicators of surface water quality within the Ukrainian Polesie were found; they are the fundamental component of a long-term monitoring of the stability in the development of aquatic phytocenoses.

The paper aims to answer the following questions: What are the trends in streetscape design? And how can streetscape become more resilient to climate change in the coming years? Although the research questions of exploratory nature also challenge theoretical claims, this is a hypothetical study, designed to foster a discussion about the visions of the future streetscape and new technology for an urban sidewalk. It covers a description and a cross-case comparison of an experimental product – the Climate Tile, implemented in Denmark in 2018, and a theoretical solution – the Sponge Pavement – a model system based on the structural soil foundation and permeable surface, evolved as an idea in 2018 in Poland. The cases are examples of innovations selected to describe a new type of water-permeable surfaces matching the urban context. Both solutions share common features: they are in that there is no need to place heavy equipment on the project site; they match the urban context of a dense city, being smooth, resistant and easy to clean. The comparison of the Climate Tile and the Sponge Pavement allowed determining the optimal application for the given solution. It also proved the trend towards the rainwater management-oriented direction of the development of the streetscape of the future. The study results could contribute to the discussion of the streetscape of the future. We would like to focus on the idea of the Sponge Pavement for further development in laboratory tests and as the pilot project.

Small earth dams are most valuable in arid and semi-arid areas where they are used for both domestic and agricultural purposes. These dams however, continue to fail. The causes of such failures are interconnected in the sense that one can trigger the other. Most research into earth dams nevertheless, uses reductionist approaches. Such approaches do not consider the complex interactions between these modes and/or causes. This research used fuzzy cognitive mapping to identify the prominent modes and causes of small earth dam failure in Swaziland and to capture their interactions. A sample of seven earth dam construction experts was purposively selected from five institutions for individual interviews. An individual map was developed from each interview. An aggregated map was thereafter developed by combining seven individual maps. The results indicated that overtopping, piping and sliding were the common modes of earth dam failure. Overtopping was mainly due to siltation whilst animal barrows and tree roots were largely responsible for piping. Sliding was mostly associated construction defects and sudden drawdown. It was concluded that most of the failures were linked to poor management of catchments and that of the dams. It is recommended that future designs and management should increase the level of community participation in order to limit some of the causes associated with land use practices.

The paper presents the problem of the growing water deficit and the possibility of sustainable development of water resources in rural areas of Central and Eastern Europe (using the example of Poland). It is estimated that the amount of resources in this region is reduced by about 70% compared to the average for Europe. In drought periods it comes to limitation of economic activity, including agriculture. Particular attention was paid to the necessity to extend landscape, underground, and snow retention, as an alternative to dams, which are currently the most popular in lower-order catchments. It has been shown that the construction of small agricultural reservoirs is not always preceded by adequate consultations and pre-design studies, which may result in financial losses and legal problems. Simultaneous use of many alternative forms of retention should be more effective than the implementation of reservoirs. In addition, increasing the hydraulic roughness of the catchments slows down the outflow of products of erosion and contributes to the protection of surface retention structures (maintaining natural and economic usefulness of reservoirs).

The historic municipal park located in Zduńska Wola is covered in the central and northern part by conservator protection through an entry in the register of monuments and on the basis of an entry in the local spatial development plan. In terms of nature, the area has significant values due to old trees and the water system, which consists of two ponds fed by the Pichna River. As part of the preparatory work for the revalorization of the park, several studies and analyses were carried out, including assessment of the sanitary state of waters of Pichna River that supplies reservoirs. Degree of the river pollution made it impossible to restore the water system, the most important element of the park, while further supplying the ponds with river water. In order to ensure a satisfactory degree of purity and transparency of water in ponds, a decision was made to apply complex and modern technological solutions enabling the renovation of the water system. Project documentation was developed in 2015. After two years, they began to implement the project. Banks of both ponds were formed more gently, and the basins were deepened. Selection of vegetation around the reservoir and in the reservoir itself was based on the principle of biocenotic assumptions. The designed system is equipped with a circulation pump, skimmers, bottom drains, mechanical-mineral filter, swamp filter. This was to ensure adequate purification of water in ponds, based on natural processes, stimulated by the use of new, pro-ecological technologies.

Hydrobionts are considered as highly potential source for bioproduction (including energy carriers and fertilizers) and many biotechnological processes that include hydrobionts, particularly their biomass as a substrate are used in different fields of energy, cosmetology, medicine, pharmaceutics, aquaculture, agriculture, forestry etc. Latest developments prove efficiency in applying anaerobic digestion for purifying wastewaters from organic pollutants with the help of macrophytes and microphytes in conducting biomethanogenesis. Many studies have established that it is possible to reach high level of lipid extraction from algae (to 95%) with the help of organic solvents (methanol, acetone, hexane, diethyl ether etc). Blue – green algae biomass has been scientifically proved to be a good source for methane, methanol, ethanol, propanol, isopropanol, biodiesel and other biofuel types production. Macroalgae and microalgae contain β- carotene, biotin, folic acid, fucoidans, lectins, phenolics, sulphated polysaccharides and other derived biologically active compounds that can be used in producing vitamins, have anti-ulcer, antioxidant, antibiotic, antifouling, immune modulatory and other properties. Cyanidioschyzon merolae, Ostreococcus lucimarinus, O. tauri, Micromonas pusilla have shown high potential for hydrogen production while Rhizoclonium sp. has been experimentally used as a bounding material in briquetting miscanthus granules, resulting in 20 % higher dynamic strength. The article is a literature review and the purpose of this work is to classify and systemize hydrobionts, reveal regularity of their growth, conduct critical analysis on existing biotechnologies on using separate representatives of aquatic biomes as a raw material and also to review ways of intensification for these biotechnologies.

The aim of the study was to analyse the state of flood-prone areas development in 10 towns on the Warta River in the Wielkopolska region in terms of the possibility of adapting existing and planned buildings to flood risks. A significant percentage of the areas exposed to floods was the basic criterion for selecting three towns for the second stage of the research. The analysis of the content of 22 local spatial development plans (LSDP) in three selected towns has revealed that the plans for special flood hazard areas (SFH) and embanked areas lack precise requirements for flood adaptation. The research proved that small riverside towns in Wielkopolska region insufficiently use planning tools to create appealing and resilient waterfronts and reduce their vulnerability. New buildings not adapted to changing water levels are still being built in the flood-prone areas, because LSPD plans do not impose such requirements. The authors proposed the graphical analysis method (based on overlay maps), which allows to indicate the areas requiring special flood-adaptation guidelines. The building and site recommendations in LSDP should refer to BFE level and may include various types of amphibious architecture and their location conditions, which has been identified in the study.

The aim of the study was to evaluate the tourism and recreational space of Lubaczowski County in Poland. The evaluation was carried out by using a multidimensional comparative analysis while taking into account tourism assets, transportation accessibility, natural environmental protection, the level of tourism infrastructure development as well as the factors contributing to an opportunity for the development of tourism via investment attractiveness (the level of infrastructure development, population relations, or the financial situation of the communes). Moreover, a questionnaire survey was carried out among the inhabitants with the aim of learning of their opinions on tourism assets and tourism infrastructure development in the commune. The study is supplemented by a comparison of the analysis results with the results of a questionnaire survey conducted among the Lubaczowski County inhabitants, which concerned the county’s attractiveness to tourists. Based on the evaluation and the questionnaire survey results, it was found that urban communes of Lubaczów and Horyniec-Zdrój had the best conditions for tourism development. These communes took the first (0.701) and the second (0.492) position in the ranking, respectively. Both communes are characterised by well-developed accommodation and catering facilities, a wealth of natural assets, and good transportation accessibility. For the better development of tourism in the county, it is necessary to take appropriate measures aimed at eliminating limitations and highlighting the strengths. To this end, it will be necessary to incorporate measures aimed at enhancing the quality of tourism infrastructure development and establishing a marketing plan that will allow tourists to learn about the tourism assets of the commune into the strategy for commune development.