Faced with the challenges of sustainable groundwater resource management in the arid zone, the identification of re-serves and their monitoring have become vital. This paper aims to identify the Turonian aquifer in the Cretaceous Béchar basin, and calculate its transmissivity, permeability and storage coefficient, as well as its evolution over time. This Tu-ronian aquifer is characterized by marine limestones (gentle dip shelters 45° to the North and 5° to 10° to the South). Pumping tests revealed a transmissivity T of 10–4 to 10–2 m2·s–1, a permeability K of 10–6 to 10–4 m·s–1 and a storage coeffi-cient S of approximately 10–3. Two piezometric campaigns, carried out between (1976–2018), show a converging and con-stant flow direction from the North–East to the South–West and from the North–West to the South–East towards the outlet of the basin. Decreased values were observed in the North and South–West borders due to isopiezometric lines. However, this water table is not in a stationary state, it shows seasonal and interannual fluctuations in relation to the variable rainfall and the exploitation rate. In terms of facies, the projection of the two hydrochemical campaigns, during 1976 and 2018 on the Piper diagram, did not show any significant evolution, they are concentrated in the chlorinated and sulphated calcium and magnesium facies.

The aim of the work was to determine the technological reliability of the selected pollution indicators removal BOD5, CODCr and total suspension from the sewage treatment plant working with the bioreactor Pomiltek Mann type. Wastewater treatment plant which is a subject of this study is located in Lesser Poland, in Siepraw commune. The analysis was per-formed using the Weibull method for basic indicators of impurities, BOD5, CODCr and total suspended solids. Physico-chemical analyses of raw and treated wastewater, were carried out in the period from 2003 to 2014 (11 years). The research period included measured values of pollutions indicators in 38 samples of raw and treated sewage. For each of pollution indicators descriptive statistic, percentage reduction (��) and treatment plant reliability factors (RF) were calculated. Aver-age reduction for BOD5 and TSS was on level equal 94%, only for COD the average reduction was lower and was on level 89%. The reliability values determined by Weibull method, were: 75% (BOD5), 90% (CODCr) and 89.5% (TSS). The relia-bility results have been lower than the presented by literature source, which means that work of wastewater treatment plant in Siepraw was not satisfied in 11 years of research.

The purpose of the research is to establish the total number of ponds in Ukraine and to analyse the territorial distribu-tion in the administrative areas, as well as in the river basin districts, as the main hydrographic units of water management. Cadastral data of the State Agency of Water Resources of Ukraine regional offices as of 2019 was used in the research (as to Crimea, Donetsk and Luhansk regions we applied the data as of 2014). According the researches there are 50,793 ponds in Ukraine with a total water table area of 2,92899 ha and the volume of 3,969.4 mln m3 of water in 2019. The quantitative distribution of ponds across Ukraine is unequal. Most of them are concentrated in the central part of the country (10.5% of the total number of ponds in the country are in Vinnytsia region). Least of them are in Luhansk region (0.7%). Almost half of the ponds are located in the Dnieper River Basin (48.5%). The lowest quantity of ponds is in the Black Sea Basin (1.2%). The regulation of river basins districts (the rivers of the Sea of Azov, Crimea and Black Sea Basins) reaches 0.71–0.77. As of 2019, 28% of the ponds are rented out. In order to identify the real status of the ponds (both quantitative and qualitative), their recreational role, the environmental impact and the regulation of the hydrographic network in Ukraine, it is necessary to increase the attention to ponds monitoring.

Recently, Google Earth Engine (GEE) provides a new way to effectively classify land cover utilizing available in-built classifiers. However, there have a few studies on the applications of the GEE so far. Therefore, the goal of this study is to explore the capacity of the GEE platform in terms of land cover classification in Dien Bien Province of Vietnam. Land cover classification in the year of 2003 and 2010 were performed using multiple-temporal Landsat images. Two algorithms – GMO Max Entropy and Classification and Regression Tree (CART) integrated into the Google Earth Engine (GEE) plat-form – were applied for this classification. The results indicated that the CART algorithm performed better in terms of mapping land use. The overall accuracy of this algorithm in the year of 2003 and 2010 were 80.0% and 81.6%, respective-ly. Significant changes between 2003 and 2010 were found as an increase in barren land and a reduction in forest land. This is likely due to the slash-and-burn agricultural practice of ethnic minorities in the province. Barren land seems to occur more at locations near water sources, reflecting the local people’s unsuitable farming practice. This study may provide use-ful information in land cover change in Dien Bien Province, as well as analysis mechanisms of this change, supporting en-vironmental and natural resource management for the local authorities.

This work aims to evaluate the treated wastewater from the activated sludge treatment plant in the City of Sidi Bel Ab-bes (North-Western Algeria) which is required for reuse in irrigation. The control of irrigated areas downstream is done based on a pedological study. Physico-chemical analysis such as (pH, BOD5, COD and SS) indicate results in Algerian and international standards required by the WHO. The Sodium Adsorption Ratio and Electrical Conductivity values of the treated wastewater belong to the C3-S1 class. The treated wastewater has a fairly good microbiological quality that meets Algerian standards. The helminth eggs are practically absent. The concentrations of heavy metals are much lower than the limits prescribed in the Algerian decrees. Therefore, the overall processing plant efficiency is satisfactory and has the char-acteristics of a good treated water quality for reuse in the field of irrigation while protecting the environment. The pedolo-gical study of the soil samples shows that the most dominant fraction is undeveloped calcimagnetic. The planned irrigation plain covers an area of about two thousand hectares. Depending on the crops to irrigate; the development and nature of the necessary or recommended improvements, the proposed irrigation perimeter could be classified into five categories in which only three categories are irrigable. Water projects have been proposed to ensure the irrigation of three subdivided sectors.

The results of the study of the macrophytes of the rivers Turia, Vyzhivka and Tsyr, the right-bank tributaries of the upper reaches of the Pripet River, are presented. The species composition of aquatic and coastal aquatic vascular plants was investigated during the vegetation seasons of 2018 and 2019 at 9 observation points located along the rivers from the source to the mouth. The most numerous species composition, 57 species, was found in the Turia River, 36 in the Vyzhivka River, and 28 species were identified in the Tsyr River. The macrophyte index for rivers (Pol.: makrofitowy indeks rzeczny – MIR) was determined from the results, and the ecological state of the rivers was assessed according to the methodology of the macrophyte assessment of rivers (Pol.: makrofitowa metoda oceny rzek – MMOR). The investigation showed that water quality in the Turia River on sites No. 1, 3 and 4 belongs to class III, satisfactory category. The surface water quality on site No. 2 of the Turia River belongs to class II, a good category. The water quality in the Vyzhivka River on all test sites belongs to class II, a good category, which testifies to favourable ecological conditions for the development of higher aquatic plants along the whole course. The water quality in the Tsyr River on test site No. 8 (Kamin-Kashyrskyi, upper course) corresponds to class II, good category. On test site No. 9 (middle course), the quality of surface waters of the Tsyr River worsens to the class III, satisfactory category.

Based on the analysis of a number of studies, it was found that to assess the state of the environment (including surface waters and soils) it is advisable to use indicators of microbiological pollution, which in general integrally reflect the state of the ecosystem. To assess the dynamics of changes in the pollution of the studied areas, a comparison of monitoring data with the corresponding level of pollution in protected areas (Vyzhnytsia National Nature Park) was used. Research methods included soil and surface water sampling, inoculation on appropriate nutrient selective media, counting of colony forming units (CFU) and other microbiological indicators. To assess the biological activity of soils, urease activity was determined by a method generally accepted in biochemistry. It is established that within the protected areas, despite some existing annual fluctuations, the relative stability of the studied indicators of the hydrosphere is preserved. Studies have shown that soils of anthropogenically altered landscapes are characterised by a high content of sanitary-indicative bacteria. As our research shows, according to the colony forming units (CFU), total microbial count, and titer of Escherichia coli, the soils selected in the protected area of the Vyzhnytsia National Nature Park correspond to the “pure” level. The soils of the territories out of the National Nature Park are characterised by high biological capacity, as evidenced by the level of activity of the enzyme urease and the ratio of the main forms of nitrogen compounds.

There is a cascade of hydroelectric power plants built on the Váh River. From a water-management point of view, the natural channel is used to drain extreme discharges. During most of the year, discharges are regulated by water-management structures. These discharges are not used for energy-related purposes; therefore, it is important to determine the optimal discharge that will not negatively affect the ecosystem of the stream. The minimum balance discharge (hydro-ecological discharge) was determined based on the instream flow incremental methodology (IFIM) using the riverine habi-tat simulation system (RHABSIM). Input data were obtained from direct measurements on three reference reaches in the area between the cities Piešťany and Nové Mesto nad Váhom. Hydraulic flow characteristics were derived from three measurements at different water levels. Habitat quality was represented by ichthyofauna. Data to determine the habitat suit-ability curves of fish were obtained using a diving technique to collect video footage. The modelling resulted in the quanti-fication of the effect of discharge on ichthyofauna as a bio-indicator of habitat quality, which implied the need of 20 m3∙s–1 for a minimum balance discharge in summer.

Flood risk management are considerably influenced by several factors, such as all sources of flooding, social circum-stances, policy and even the potential for local economic growth. To encourage government, business, community and oth-er parties to continue investing in flood risk management projects, it is necessary to give understanding that the projects can also provide economic benefits through systematic predictions and assessments of costs, benefits and social values, espe-cially on flood-affected communities. This study aims: (1) to develop knowledge and understanding on small-scale flood risk management project in Malang City, Indonesia, and; (2) to assess the economic efficiency of the project investment considering all benefits, both monetary and non-monetary. The research method is a mixed method combining quantitative questionnaires (N = 53 from 162 families) with qualitative in-depth interviews (N = 10) and field observations. The runoff discharge and the inundation depth were calculated using hydrology and hydraulic analysis, while the economic efficiency was analysed using cost benefit analysis (CBA). The results show that the community-based flood risk management system can reduce the flood risk up to 30% compared to before the implementation of that system. This system also provides direct financial benefits through the use of drainage channels for fish and vegetables farming. It causes the increase of the net so-cial benefit about 70–90% and the net present value (NPV) greater than zero (NPV > 0). Therefore, the project investment is recommended to be proceeded.

In the present work, the dried biomass of soil isolated fungus Eurotium cristatum was used for synthesizing silver na-noparticles (AgNPs). The synthesized AgNPs were spherical in shape with average diameter of 16.56 nm and displayed maximum absorbance at 418. Fourier transform infrared (FTIR) study indicated the presence and binding of proteins with myco-produced silver nanoparticles. The optimum conditions for AgNPs biosynthesis were found to be at temperature of 40°C, pH of 8.0, substrate concentration of 500 ppm and fungal biomass wt. of 0.8 g. The AgNPs showed antibacterial ac-tivity against Staphylococcus aureus, Listeria monocytogenes, Escherichia coli and Shigella flexneri. AgNPs was built-in thin film nanocomposite (TFNC) membrane and the impacts of nanomaterial composition on membrane properties and de-salination process were studied. The AgNPs produced membrane TFNC had better filtration performances than pure thin film composite membrane TFC. The TFNC membrane had enhanced water flux (32.0 vs. 16.5 dm3∙m–2∙h–1) and advanced NaCl rejection (91.7 vs. 89%) compared to the TFC membrane. A pot experiment was conducted to evaluate the effect of the irrigation with desalinated water on yield and productivity of essential oil of the sweet basil (Ocimum basilicum L.) and lavender (Lavandula multifida L.). The irrigation with desalinated water reduced significantly the soil reaction, soil electri-cal conductivity (EC), sodium adsorption ratio and exchangeable sodium percent in rhizospheric soil, it also enhanced the growth and oil yield of both plants compared with those irrigated with salt water.

The present study aimed to assess groundwater quality according to the water quality index (WQI) in Ali Al- Gharbi district of the Maysan Governorate in eastern Iraq. For this purpose, 10 physical parameters such as pH, total hardness ( TH), magnesium (Mg2+), calcium (Ca2+), potassium (K+), sodium (Na+), sulphate (SO42–), chloride (Cl–), nitrate (NO3–), and total dissolved solids ( TDSs) were examined since 2019 from 16 different locations (viz. wells). The analysis results indicated that 18.75% of the water samples were of good quality, 56.25% of them had low quality, and 25% of such samples were very poor. The WQI also varied from 69.67 and 297.6. Therefore, prior to water use, there is a dire need for some treatments, as protecting this district from pollution is significant.