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Abstract

The surface sediments of Seybouse River and its affluents have been studied and assessed to determine their degree of heavy metal contamination (Cd, Pb, Cu, Ni, Zn and Fe). The contamination factor (CF), the contamination degree (CD) and statistical tools (correlation and APC) has been used in assessing: metal contamination, sediment toxicity and to identify the origin of metals which have enriched the sediments. Heavy metals concentrations of sediments are generally heterogeneous and vary according to the metal and the sampling site. The results have been compared to the reference values of the unpolluted sediments and have shown that Seybouse River sediments are more contaminated by Pb, Cd and Zn respectively. CF values indicate moderate to considerable contamination for most stations. CD values show that the most toxic sediments are located mainly at the estuary and downstream of large agglomerations. The matrix correlation between the metallic elements shows a very strong correlation between Pb, Cd, Cu and Zn indicating that they have a similar source. These different metallic elements appear as traces of anthropogenic pollution. Despite using wastewater treatment plants as protective measures, Seybouse River pollution is remaining a big issue and more efforts has to be done by local authorities.

Abstract

In the article we developed the design principles and implementation of a complex model and optimized the design parameters of drainage. The study was based on the implementation of interconnected structural and technological forecasting simulation and optimization model blocks, which in turn allowed to justify the optimal design parameters and drainage considering multiple natural and agronomic conditions and reclamation facilities. Example of evaluating the performance of drainage on drained lands was made for the conditions of a real project, implemented on lands of agricultural holding “May Day” located within of drainage system “Ikva” in the Rivne region. For the object conditions (average decade formation conditions of the drainage flow module for growing perennial grasses, winter cereals and potatoes) the estimated duration of the growing season was 214 days (100%), of which the total duration of drainage was 60% and included different levels of efficiency: 39% – ecological, 15.5% – technological and 5.5% – economic. The duration of its critical operations (forming module drainage flow exceeds the design of its value) does not exceed 5%. Thus, this approach enables the assessment of drainage with predetermined or specified parameters in the construction or renovation of drainage systems on different levels of effectiveness. It can be effectively used in the overall complex predictive and optimization calculations to substantiate the design and parameters of agricultural drainage, taking into account the variability of natural agrotechnical and reclamation conditions of a real object.

Abstract

In this paper, the capacity of an Adaptive-Network-Based Fuzzy Inference System (ANFIS) for predicting salinity of the Tafna River is investigated.

Time series data of daily liquid flow and saline concentrations from the gauging station of Pierre du Chat (160801) were used for training, validation and testing the hybrid model. Different methods were used to test the accuracy of our results, i.e. coefficient of determination (R 2), Nash–Sutcliffe efficiency coefficient (E), root of the mean squared error (RSR) and graphic techniques. The model produced satisfactory results and showed a very good agreement between the predicted and observed data, with R 2 equal (88% for training, 78.01% validation and 80.00% for testing), E equal (85.84% for training, 82.51% validation and 78.17% for testing), and RSR equal (2% for training, 10% validation and 49% for testing).

Abstract

The article analyses the water quality of the Lower Cretaceous aquifer in the Beni-Ounif syncline. To this end, 42 samples were taken for physico-chemical analysis and 28 for microbiological analysis in March, May and October 2017 from 14 sampling points. The results of physico-chemical analysis were processed by multi-variety statistical analysis methods: principal component analysis (PCA) and hierarchical cluster analysis (HCA) coupled to hydro chemical methods: Piper diagram.

The PCA allowed us to explore the connections between physico-chemical parameters and similarities between samples and to identify the most appropriate physico-chemical elements to describe water quality.

The HCA allowed us to classify the sampling points according to the similarity between them and thus reduce them for the next follow-up analysis.

Waters of the syncline are characterized by medium to low mineralization (320 < EC < 7600 μS∙cm–1 and 200 < RS < 4020 mg∙dm−3) and hardness of between 22 and 123°f. Only 19% of the samples show NO3 concentrations exceeding the Algerian standards.

Microbiologically, the study reports the presence of bacteria: coliforms (<8 CFU∙0.1 dm−3), Streptococcus D (<1100 CFUꞏ0.1 dm–3), Clostridium sulphito-reducer of vegetative form (<90 CFUꞏ0.02 dm–3) and sporulate (<4 CFUꞏ0.02 dm–3), total aerobic mesophilic flora at 22°C (<462 CFUꞏ0.001 dm–3) and at 37°C (<403 CFUꞏ0.001 dm–3). It must be noted that no presence of thermo-tolerant coliforms is observed.

Abstract

To resist against a hostile environment, the oases of Saoura developed ingenious techniques of catchment and sharing of water to exploit the rare and precious waters of the groundwater. But the intervention of modern irrigation techniques has disrupted the entire oasis system inside the oasis such as the spring, the palm grove and the ksar. These techniques have overexploited the groundwater supplying the palm grove in terms of quantity and quality.

For centuries, the oases of Mougheul used only the source (with a flow of 25 dm3∙s−1 in 2001) which is inside the oasis to irrigate the parcels and herds. After the year 2005, the state decided to supply the city of Bechar with drinking water through the catchment field of Mougheul through five modern boreholes, which had a profound impact on the oasis, its surroundings, and the whole artesian source.

In this work, we study the impact of the use of modern catchment systems on the water source and the life of the Mougheul population. By interviewing farmers and landowners about the impact of groundwater scarcity on the oasis. This allowed knowing the current state of the oasis and the reasons for its deterioration.

Abstract

Flood modelling is an effective way to manage the stormwater network in cities. It aims to understand and predict the behaviour of stormwater network so that it can test and evaluate effective solutions to structural and operational problems. So simulation modelling stays a preoccupation for building a successful hydraulic modelling in urban areas. This study investigates the impact of the design rainfall on the hydraulic modelling results for the Azzaba stormwater network located in the North-East of Algeria by using the Storm Water Management Model (SWMM). Four scenarios of design rainfall events were compared for 10, 25 and 50-year return periods, where we used double triangle and composite curves for the design rainfall event definition. The results show the impact of the choice of design rainfall on the behaviour of the stormwater network, from which the results of simulation by the double triangle method for the short durations represents a great risk on the probability that the stromwater network can overflow and flood the city, with a difference in peak discharge estimated at 62.97% and 58.94% for 2 h and 3 h events compared to the peak discharge simulated by the composite rainfall method.

Abstract

The aim of the study was to determine the morphological characteristics of selected spring-heads in the Knyszyńska Primeval Forest and to identify lithological conditions in areas where groundwater flows to the surface. During the study, detailed bed level measurements of the spring-head areas were conducted. Lidar laser data obtained from the Central Department of Geodetic and Cartographic Documentation in Warsaw were also used for the analysis of morphometry. Based on the data, the detailed contour maps were created in the Surfer 12 programme and the basic parameters of the morphometry of the studied springs were determined. To detect lithological conditions, granulometric analyses were conducted and the filtration coefficient of aquifers in the individual spring-heads was calculated using Hazen and USBSC empirical models. Due to the morphological situation, the examined objects were classified as sub-slope and riverbank spring-heads. In terms of shape, spring-head alcoves are classified as basin-shaped, bowl-shaped and spindle-shaped alcoves. Different morphological processes prevail in each of these types. Basin-shaped alcoves are formed mainly by lateral erosion, bowlshaped alcoves by seepage erosion, landsliding and accumulation in the bottom, spindle-shaped alcoves by seepage erosion, headward erosion, breaking and collapsing. In the investigated outflows of groundwater aquifers are sands and glacifluvial sands with gravel of varying grain size. The lithological variation of aquifers in the spring-heads, directly affects the rate of groundwater filtration in different parts of the alcoves, which in turn leads to different morphogenetic processes and results in changes in the morphology of the spring-head alcoves.

Abstract

The article presents the analysis of water level fluctuations in Lake Powidzkie in the years 1961–2015. The study shows a considerable decrease in mean water levels in the aforementioned multiannual period, averaging 9 cmꞏdecade−1. Such a situation is caused by natural as well as anthropogenic factors, co-determining water relations in the study area. The natural factors include the amount and distribution of precipitation, increase in air temperature and evaporation size, unfavourable relations between the lake and catchment or hydrogeological conditions. Anthropogenic factors particularly include long-term transformations of the natural environment in the region, currently associated with meliorations accompanying the nearby opencast brown coal mines and exploitation of groundwaters for municipal purposes. Water shortages occurring during dry periods were shown not to be compensated in the study area in humid years. This is particularly related to the regional lowering of the aquifer remaining in close relations with Lake Powidzkie. Counteracting the unfavourable hydrological situation is done through hydrotechnical infrastructure which partially limits water outflow from the lake through damming.

Abstract

The purpose of the work described in the article was to find the optimal location of the pumping station for the mining area Krzyżowice III Hard Coal Mine “Pniówek”. Mining exploitation causes lowering of the area and changes in water relations. Hence, it is necessary to perform a gravitational, and if it is impossible, forced outflow of water. Localization of the pumping station should assure removal of excess water and prevent flooding. Not only was the present relief taken into account, but also the entire period of the mine’s existence. On the basis of the results of airborne laser scanning a digital terrain model (DTM) was generated. Then a catchment division was made for the entire analyzed area. The article presents the workflow of performing the simulation as the area will be changed due to forecasted mining operations. A practical way to solve the problem of simplifying large amounts of data was also shown. The obtained source materials were developed with the use of the Geolisp software. The system operates in a CAD graphic environment and allows for automation of the most frequently performed works in the field of mining map preparation. The Geolisp cooperates with EDN-OPN program. Thanks to this fact it is possible to combine the obtained results of calculations of predicted deformations of the mining area and the rock mass with the digital map.

Abstract

The paper presents the assessment of possibilities and limitations of the use of Lemna minor, Hydrocharis morsus-ranae and Ceratophyllum demersum in removing metals from contaminated waters. Synthetically discussed the role of these species in phytotechnology and their importance in the assessment of surface water status. The variability of concentration of selected metals in waters and the content of metals in the organs of the analysed plants are presented. Their advantages and disadvantages in removing metals from waters due to biological features have been characterized. Minimum and maximum efficiency of metal removal depending on the scale of water pollution was determined. It was found that analysed plants can be used for phytoremediation of metals from water, but the limitation of effectiveness of treatments is the toxicity of these metals to plants and the time of exposure. The highest removal efficiency can be obtained thanks to the use of sequences of single-species filtration systems.