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Studies on the effect of climate change on water resources in the 21st century indicate an increase in intense rainfall, an increase in the duration of the dry season, and a decrease in snowfall and, accordingly, snow cover. Based on data from the EURO-CORDEX project, the average multi-year monthly runoff amounts (Copernicus Climate Change Service, Climate Data Store, 2021) for each 30-year period and for the reference period for a rectangular area covering the territory of Bulgaria have been calculated. Climatic ...

Anthropogenic imprints, including hydromorphological pressure and illegal land use through unauthorised dumping and wastewater discharge, are various forms of human activity that often have lasting impacts on the natural environment. Despite this, integrating them into ecological assessments and water and natural resource management remains underexplored at the river basin scale. This study aims to investigate and analyse illegal dumping and pressures on freshwater resources in the Chepinska and Chepelarska River ...

This article examines the mineral composition of the waters of important rivers in the Adjara region: the Chvana, Adjaristkali, Merisi, and Chorokhi. These rivers are part of the Black Sea basin and are used for drinking water supply, domestic needs, and agriculture, while the Adjara region is an important tourist destination. The study was conducted using an IGPE-9820 plasma atomic emission spectrometer. The concentrations of aluminum, boron, barium, beryllium, arsenic, calcium, cadmium, cobalt, chromium, copper,...

This paper evaluates the potential of formation waters from mature oil fields of the Volga–Ural petroleum province as a source of valuable components. The study addresses the growing demand for strategic elements such as lithium, bromine, strontium, and rare earth elements, and the need to identify alternative resource bases. The research is based on a review and analysis of published geochemical data on produced waters from major oil fields, including Romashkinskoye, Orenburgskoye, and Arlanskoye. The concentra...

Unmanned aerial vehicles (UAVs) are increasingly used in many industries and environmental monitoring systems. They play a particularly important role in the observation and research of difficult-to-access areas, such as watercourses, river basins, reservoirs, and wetlands. The ability to quickly measure basic physicochemical parameters of water, such as temperature, electrical conductivity, pH, and turbidity, is crucial for assessing the condition of the aquatic environment and initiating appropriate actions. The...

This study investigates the development of gravel-gelatin composites as pre-formed monolithic filter elements for borehole wells in unconsolidated sandy aquifers. The composites utilize food-grade gelatin as a natural, biodegradable, and low-cost binder to bond gravel particles into stable blocks, offering an alternative to conventional loose gravel packs that are labor-intensive to install and prone to placement inconsistencies. A systematic experimental approach was employed to optimize key manufacturing paramet...

Mining activities can significantly affect water resources by altering their chemical composition and promoting the mobilization of contaminants in aquatic systems. In this context, this study analyzed the hydrochemical and isotopic characteristics of hydric resources in a mining-impacted region of southern Ecuador in order to identify the main processes controlling water chemistry, determine the origin, and identify potential sources of contamination. Eighteen water samples were collected (10 surface water and 8 ...

Forest evapotranspiration is a key component of the water balance in mountain ecosystems and plays an important role in regulating regional hydrological processes. Accurate assessment of evapotranspiration, a key component of the water cycle, remains challenging due to the spatial and temporal variability of vegetation water use and the limitations of individual observation methods. The objective of this study is to assess forest evapotranspiration in the Rhodope Mountains (Bulgaria), simulated using the open sour...

The present study investigates water consumption patterns in 11 secondary and high school buildings in Sofia, Bulgaria, and evaluates the adequacy of the current regulatory requirements for this category of public buildings. Water consumption and pressure were monitored at one-minute intervals during two annual two-week measurement campaigns for each facility, resulting in a database covering 368 days. Water losses were identified through minimum night flow analysis and excluded from the assessment of effective wa...

The main objective of this study is to outline the spatial distribution of precipitation deficit at both monthly and annual scales by comparing precipitation data from two reference periods: 1961–1990 and 1991–2020. To achieve this goal, monthly and annual precipitation normals from 355 meteorological stations throughout the country are calculated in accordance with the World Meteorological Organization's standards. Data post-processing, statistical analysis and spatial interpolation are performed in the R env...

The aim of this work is twofold: to identify the dominant types of anthropogenic impact on SWQ in the Chepinska and Chepelarska River basins to localise the hot spots of pollution; and to obtain the main land cover units from Very High Resolution (VHR) Airbus Pléiades-1A and SPOT 6 imagery. The assessment of anthropogenic impacts on SWQ is based on an analysis of more than 10 physicochemical parameters, and the CCME WQI, WAWQI, and HPI indices were used. The results show different types of water pollution in the ...

The WatHer project – Water Heritage in European Rural Mediterranean: Re[dis]covering Water Heritage Systems to face climate challenges learning from our past – is funded by the European Union under the Interreg Euro-MED Programme and aims to promote climate change adaptation and disaster risk prevention through ecosystem-based approaches. Running from 2025 to 2029, the project is structured around eight pilot cases across the Mediterranean Basin, from Cyprus to Portugal, focusing on the study, restoration, and...

When designing hydraulic, power and civil structures, special attention is paid to the study of the stress-strain state (SSS) of foundations from the soil environment. The operation of such structures often leads to changes in the SSS of the soil base, which can affect their stability. It is known that the SSS of soil bases significantly depends on the physical and mechanical properties of soils, hydrogeological conditions of the environment and the type of loads, in particular on the filtration of groundwater, ma...

The paper presents a trend analysis in monthly precipitation, air temperature (average, minimum and maximum), air temperature range, potential evapotranspiration, drought and water balance over Romania using data from 156 weather stations. The recently released, freely available RoCliHom dataset has been used for this purpose. Trend analysis was conducted with the nonparametric Mann-Kendall test, as it allows a direct comparison with the vast majority of previous studies on climatic changes in Romania. Our results...

Industrial activities in the Jiu River basin, especially coal mining, have generated a significant impact on water quality over time, by releasing variable concentrations of heavy metals into the environment. This paper analyzes the trends of variation over time of the degree of heavy metal pollution in the Jiu River, considering the direct influence of the extractive industry in the area. The study is based on data collected from multiple water quality monitoring campaigns, covering an extended period, and aims t...

Water discharges, suspended load and hydrochemistry for 35 inflows of largest Caucasian Lake Sevan were measured 3 times in different hydrological seasons during 2024 and 2025. During summer most of small streams dried out while in winter a number of rivers were frozen into the bottom. The water discharges varied from 0.01 in summer to 8.02 m3/sec in spring. Large natural inflows are Argichi, Dzknaget, Gavaraget, Masrik rivers with water discharges in spring 8.0, 6.3, 4.5, 2.8 m3/sec correspondingly. By the end of...

This study explores the application of the Analytic Hierarchy Process (AHP) to identify groundwater retention potential within a 130 km- study area, leveraging high-precision LiDAR measurements and data from 150 wells. By integrating advanced geospatial technology with extensive field data, this approach offers a unique methodology for analyzing groundwater retention. AHP was employed to assess several key geographical factors, including the Topographic Position Index (TPI), slope, hydrographic network density, la...

The fish farming infrastructure in the Danube Delta, including the Popina Fish Farm Enclosure, has been significantly impacted by environmental factors, particularly due to climate change. Located in the northeastern part of the Danube Delta Biosphere Reserve, near the Chilia arm and the Black Sea, this enclosure once played an important role in aquaculture activities. Currently, the main threat to the area is the high water levels of the Chilia arm, which place constant pressure on the protective dykes, increasin...

The combination of Long Short-Term Memory (LSTM) neural networks, comprehensive trend analysis, and standardized pan evaporation measurements creates the capability for understanding and predicting regional evaporation dynamics in the context of climate change in this study. Based on the thorough examination of this study in the Slovak Republic's Vah river basin the K-means clustering analysis revealed three different patterns of evaporation behaviour (1.5-3.2 mm/day); the seasonal analysis revealed that peak evap...

The research was carried out to examine the influence of tributary inflows on the hydrochemical properties of the Svete River, which traverses intensive agricultural regions. Sixteen monitoring sites were selected along the main channel and at major tributary junctions. Water samples were collected monthly from surface layers (0 5 cm) over a one-year period, and concentrations of total nitrogen, total phosphorus, and selected metals were evaluated. A multi-parameter probe and an inductively coupled plasma optical ...

Floods are among the most common natural disasters in Slovakia, often causing extensive material damage and posing a serious threat to human lives. Given their frequency and potential negative consequences, it is essential for municipalities to have an effective flood risk management system in place. Municipal preparedness for flood management is a key factor in minimizing damage and involves various measures, such as the implementation of an early warning system, the development of evacuation plans, systematic pu...

This article analyzes the impact of flood events on fire brigade response activities concerning vehicles using alternative energy sources, with a particular focus on electric vehicles. Given the increasing number of electric vehicles and the observed rise in the frequency and intensity of floods attributed to climate change, the probability of these vehicles becoming submerged is increasing, posing specific challenges for fire brigades. The analysis focuses on the risks associated primarily with electric shock and...

This study assesses low-cost biochars produced from locally available agricultural residues, corn (BC-corn) and straw (BC-straw), as reactive sorbents for in situ groundwater remediation of vinyl chloride (VC). Biochars were obtained by slow pyrolysis under inert atmosphere and characterized by N2-BET at 77 K, CHNS, FTIR, XRD, and SEM/EDS. Sorption experiments were performed at 20+/-2 C in a synthetic aqueous matrix and in Danube alluvial groundwater containing elevated VC (11.6 to 17.8 ug/L) with typical backgrou...

Romania and the Republic of Moldova have a long-standing tradition of grape cultivation, one of the agricultural sectors that is highly sensitive to climate change. As the growth and development of grapevines are strongly dependent on the regional bioclimatic dynamics, this study presents projected climatic changes over Romania and the Republic of Moldova under three of the latest climate scenarios. The analysis focuses on ten biometeorological indices relevant to grapevine development (e.g. mean annual air temper...

According to Albania's geographical classification, the Mati River belongs to the North Central Highlands. From a climatic perspective, this region is characterized by significant variations in temperature and precipitation due to its diverse geographical altitudes, ranging from 1800 meters above sea level to 0 meters at the estuary. Hydrographically, the Mati River basin is distinguished by a dense network of water courses, particularly in its middle and lower sections, where ultrabasic formations dominate. Addit...

The Baltic Sea Region faces increasing pressure on water resources and ecosystems due to human activity, with nutrient rich treated wastewater discharges being a main cause of eutrophication. Combining algae-based nutrient removal with reclaimed wastewater reuse provides a sustainable solution to reduce pollution while allowing algal biomass recovery for further applications. Therefore, the aim of the study was to evaluate possibilities to use algae cultivation as a tool for nutrient removal from treated wastewate...

The river Iskar is the object of study. The development aims to update the technological scheme of the resource of surface water bodies for a new reference climatic period (1991-2020) and estimate the annual average values at the end of each water body. For the study, 20 gauging stations were used, which currently represent the NIMH monitoring network in the catchments of the streams on which the resource is based. In terms of area, the stations cover the whole catchment relatively evenly. For the study, the annua...

Heavy metals as persistent pollutants of the aquatic ecosystems become a global issue of concern and are consistently increasing due to urbanization and industrialization. The aim of this study was to determine the heavy metals content in the water of the Mati River. Heavy metal levels were monitored during 2024 on four campaigns along the Mati River. Water samples were collected from five stations, covering the whole watershed area. Sample analyses were performed by Atomic Absorption Spectroscopy, (GF-AAS). This ...

Hydrological droughts are formed by different processes, but how strong and heterogeneous they are, leading to different hydrological droughts characteristics and propagation. Droughts have no distinct starting date, but different methods gives a course of action that may help to identify dry signals and possible, drought conditions for drought early warning and predict to some certain level the magnitude and water required for hydrological drought recovery. We choose hydrological drought indices system that are a...

Climate change intensifies concurrent drought and heat stress in viticulture across Central Europe. This study assessed vineyard ecosystem stress using integrated multi-parameter monitoring over 31 months (May 2023 November 2025; n=43,763 observations). A composite Ecosystem Stress Index (ESI) integrating Vapor Pressure Deficit (30%), depth-weighted soil water availability (40%), and soil temperature gradient (30%) was developed. The year 2023 exhibited healthy baseline (mean ESI=0.1375; only 1 stress day). The ye...

Sustainable land use and resource planning are essential for reconciling resource extraction with environmental protection, particularly in mining regions. This study examines the integration of hydrological analysis into sustainable land-use planning, with a specific focus on the Bogdanka SA coal mine in Poland. The objective is to identify limitations in current hydrological methodologies and to propose enhancements that support more effective resource management. The paper reviews critical components of hydrolo...

Constructed wetlands provide a cost-effective and environmentally sustainable approach to wastewater treatment; however, their efficiency in phosphorus removal often remains insufficient to meet current discharge standards. Chemical precipitation using aluminium-based coagulants has been proposed as a promising solution. In this study, laboratory-scale columns were constructed to simulate French and Austrian types of constructed wetlands and operated in two experimental phases. During the first phase, wastewater w...

Lake Liepaja, a shallow lagoon-type lake located in the temperate climate zone, is affected by persistent ecological pressures, including nutrient enrichment, sediment contamination, and climate variability. This study presents an overview of long-term water quality dynamics based on monitoring data from the Latvian Environment, Geology and Meteorology Centre (2001-2023), interpreting key physical and chemical indicators as evidence of broader ecological trends. Multi-year records of physicochemical parameters wer...

At present moment, Bulgarian regulatory documents lack rainfall hyetographs that can be used in computer models of sewer networks. In the conditions of climate change and the occurrence of extreme precipitation phenomena, this leads to difficulties in the application of sewer network modeling in solving engineering problems. It is not possible to perform a normatively defined determination of hydraulically overloaded sections of the sewer network, as well as to determine the expected frequency of flooding and floo...

Within a catchment, evapotranspiration is considered the loss component of the water budget. High mountain basins of high precipitation and low air temperature are essential for the recharge of water resources available to lowland settlements. Recently, increasing attention has been paid to the dynamics of water resources in mountainous areas, particularly due to the lack of measurements and the expected impacts of global warming. The aim of this study is the analysis, evaluation, and modeling of evapotranspiratio...

Impact assessments of climate change commonly use either synthetic or downscaled meteorological data. Many meteorological variables are missing or uncertain in such an approach. In this paper, it is shown that in such studies, this limits the use of classical reference ET0 models, e.g., the FAO-56 Penman Monteith model, which require several climatic data inputs. The objective of this study was to assess the capability of the minimal-input approach to predict ET0 and irrigation water requirements solely from tempe...

Modern water quality monitoring in reservoir systems increasingly involves the use of multiparameter sensors and mobile measurement platforms capable of providing accurate, high-resolution data in both spatial and temporal domains. This study presents the results of a field campaign conducted at the Dobczyce Reservoir in southern Poland, where two complementary measurement strategies were employed: manual vertical profiling at fixed points, and continuous near-surface monitoring during in-motion transects using a ...

The estimation of aquifer parameters is a critical issue in groundwater modeling. Traditionally, these parameters are determined using manual curve-matching techniques. However, the accuracy of these methods heavily relies on the modeler-s expertise, which can lead to graphical or human-induced errors. To address these challenges, a coupled simulation-optimization framework is proposed for identifying the hydrogeologic parameters of unconfined aquifer systems. In the simulation phase of the proposed framework, dra...

Climate change represents one of the major environmental problems of our time (IPCC, 2021), significantly affecting plant water regimes and agricultural production. Increased temperatures, prolonged droughts, and unpredictable rainfall patterns lead to reduced soil water availability (Allen et al., 1998), increasing the urgency for efficient and precise irrigation management. As traditional methods based on soil moisture or empirical models become less effective under variable climatic conditions (Jones, 2004), th...

Peatlands are crucial carbon sinks, but their degradation through extraction and drainage results in substantial greenhouse gas emissions and ecosystem disruption. This study investigates groundwater level dynamics in a 16.4-hectare extracted peatland in Central Latvia to assess hydrological conditions relevant for restoration. Groundwater levels were monitored from May 2023 to May 2024 using TD-Diver loggers installed in six wells. The data reveal pronounced spatial and seasonal variability, with precipitation an...

This study investigates the influence of meteorological variables on evapotranspiration (ET) using a novel lysimeter design. ET was measured with three specially constructed lysimeters made from water containers equipped with geotextile bags filled with sand and colonized by grass cover (Red fescue and Perennial ryegrass). The use of geotextile lysimeters provides a simple and robust tool for ET quantification under outdoor conditions and also reflects the structural principle of evaporation beds (ET-beds), used f...

The most effective way to ensure drinking water quality and protect public health is the implementation of a preventive, risk-based approach to water supply management. This approach encompasses all stages, from the water source to the consumer, and can be applied across all water supply systems, regardless of their size. The EU Drinking Water Directive (Directive (EU) 2020/2184) emphasizes the importance of this concept. This study assesses and analyzes the risk of groundwater contamination at the water supply so...

The sludge layer formed during the first stage of French vertical flow constructed wetlands is a crucial component in achieving high removal efficiencies of water pollution, including suspended solids, chemical oxygen demand, nitrogen, and phosphorus. In the Czech Republic, persistent challenges with insufficient sludge layer development on the first stage have limited treatment performance due to the combined sewerage system. To address this, a pilot-scale experiment was conducted focusing exclusively on the form...

In the presented scientific work, a scenario forecast for the long-term perspective of water level changes in Lake Balkhash, one of the largest drainless lakes in Central Asia, is carried out. The study takes into account the impact of projected climatic changes based on CMIP6 data and the impact of socio-economic factors, including water management activities. A water balance model was used as the main tool to quantify the role of surface inflow, precipitation and evaporation in shaping the hydrological regime of...

The effects of climate change are affecting agriculture in many areas through changing weather, such as unexpected temperature swings and changes in rainfall that threaten food supplies and rural life. Western Romania has its own weather problems, such as long droughts mixed with unpredictable rains, and generally these conditions are starting to slow down agricultural production, which means farmers need to rethink the way they farm. When rains stop being reliable, groundwater can act as a buffer; it helps to kee...

The research uses monthly water flow in river watersheds within Danube-s river basin - Ogosta, Iskar, Yantra and Rusenski Lom rivers, as pilot basins. The water flow indicators describe river flow regime and hydrological streamflow characteristics. Our article describes the determination of environmental flow limits on surface water abstractions in Bulgaria. Monthly river flow is characterized by annual variability due to climate factors and anthropogenic impacts. Furthermore information from hydrometric stations ...

Surface water resources are already being utilized at maximum capacity and the trend is unlikely to change. This situation has led to increasing concerns regarding the sustainable use of this resource, with continuous efforts being made to reduce water pollution. In this context, the analysis of surface water quality is essential for protecting human health, the environment and the economy, providing significant opportunities for improving the quality of life and conserving natural resources. This paper presents t...

The increasing frequency and intensity of flood events necessitate innovative approaches for effective monitoring and modeling to mitigate risks. This article explores the application of drone technology in flood risk management, highlighting its advantages over traditional methods. Drones equipped with high-resolution cameras and advanced sensors can rapidly collect spatial data, enabling detailed topographic assessments and hydrological modeling. Their ability to access hard-to-reach areas allows for real-time m...

Reproducing the hydrological process of river runoff is a fundamental part of water resources planning and management. Finding a mathematical model to reproduce the runoff time series aims not only to extract maximum information from the limited available data, but also to extrapolate into the future by representatively generating the historical runoff process. Almost all management decisions are based on forecasts. Our present is characterized by the increasingly frequent occurrence of hydrometeorological process...

The Danube has been a traditional trade route in Europe since ancient times. Transport on the Danube has many economic and environmental advantages. By using the river as a transport route, logistics costs can be reduced, and delivery times optimized. Another feature of the Danube is its connection to the North Sea and maritime transport via the Rhine-Main-Danube Canal. In addition, waterborne transport produces less carbon dioxide than road or rail transport, helping to reduce environmental impact and promote sus...