Browse

The last several decades, the climate change, as one of the most serious environmental issues, has become a widely spread topic not only to individuals, but the whole international community. Weather extremities, such as tropical days, summer heat waves, switching of periods of extreme precipitation with periods of drought causing the decrease of water reserve capacities cannot simply be overlooked. Due to alarming climate situation, especially in urban zones, the adaptive measures are much needed, even necessary....

Combined sewerage is the most widespread method of wastewater management in the world. Sewage and rainwater are discharged through a combined piping system, which affects overloading the sewer networks during extreme rains. This method of wastewater disposal is the oldest type of sewerage. At present, this method is described as less suitable in opposite to rather on the construction of a divided sewerage system, where wastewater and rainwater flow through separate pipes. The main disadvantage of the combined sewe...

Hydrological modeling is the conventional approach to simulate, evaluate, forecast, and react to floods. However, the development and validation of these models are more challenging where the monitoring stations are limited, unevenly distributed, and particularly scarce in many developing countries. Alternatively, satellite images allow detecting the multi-temporal flood extent over large horizontal areas with a cost advantage for hydrological calibration and validation. Many approaches have been explored to disti...

During the last decades the extreme hydrometeorological events increased. Respectively the needs for more accurate estimation of the precipitation amounts have increased. One of the opportunities to get denser precipitation data in space and time is through the remote-sensing. Satellite-based products allow obtaining spatially distributed hydrologic variables and could be very useful in the modeling of the elements of the hydrological cycle. A big variety of hydrological models exist nowadays. In this study the fu...

Harmful substances like heavy metals are very important group of pollutants which can cause considerable detriment to the environment if they exceed certain concentrations. The aim of this study is to define the concentrations of Cu, Fe, Mn, Pb, As, Zn, Cd and Ni in the waters of the Rivers Pirdopska and Medetska, tributaries of the Topolnitsa River, Bulgaria for the period 2015-2019. In the analysis of the heavy metal content Water Quality Index (Canada), as well as statistical and graphical methods were applied....

Waste treatment is considered one of the critical environmental issues. Waste should be understood not only as a source of pollution but as a raw material. Nevertheless, we need well-sorted waste for recovery. Separate collection of municipal waste is an activity in which components of municipal waste are separated. It is based on the conscious activity of citizens, who primarily sort the relevant raw materials. At present, the citizen is obliged to sort waste by law in Slovakia, and the municipality is obliged to...

Combined sewer are among the most important objects of a unified sewerage network and therefore high requirements are placed on these objects, whether from hydraulic, hydrological, hygienic or constructional requirements. Their main function, ie hydraulic, is to divide the inflow at the time of torrential rains into a flow continuing to the WWTP and a flow that is relieved from the OK to the recipient. Another important function of relief chambers is related to pollution. Some chamber designs can successfully capt...

Water management in karst areas is a challenge as the regime of waters is generally characterized by substantial temporal variability. Water balance analysis is a necessary part of hydrogeological research. The aim of the paper is to study specific features of the water regime and balance of karst springs from the Lovech-Tarnovo karst basin, as well as to evaluate their recharge area. For monthly water balance calculations, the software WaterbalANce was used that is based on the Thornthwaite–Mather method. In addi...

The Volga River is today a cascade of lowland reservoirs. This allows flood prevention, river-sea navigation and hydropower generation. There are also disadvantages, such as the flooding of fertile floodplain lands, a decrease in water quality and drastic algal blooms in the summer season. Due to the problems triggered by the current system, alternative solutions have been proposed that include a decrease in the amount of water stored and a reduction in energy production being, which can be compensated with floati...

In studying WRS that belong to complex probability systems, it is necessary first to make a mathematical description of the input process of the system - the process of changing the river flow. The use of the available series, which cover several decades of years (in Bulgaria about 30-70 years), cannot reflect the alternation of sequences of high-water and low-water years and the great diversity of the intra-annual runoff distribution, which characterizes the different water years. For these reasons, studies based...

The objective of the study is to calculate with highest reliability the values of the maximum runoff with different probabilities in Nishava catchment, in relation to elaboration of flood risk maps for Godech town. To calculate the maximum runoff of the Nishava catchment, the regionalization method was applied. This method was developed in the state of Baden-Wurttemberg, Germany and is widely used in practice. It is based on eight characteristics and factors of catchment areas and river systems: catchment area; ur...

The interaction between groundwater and surface water is a complex process that plays an important role in the functioning of the ecosystems, the understanding of this interaction being significant for the management and protection of water resources. Moreover, this interaction can affect the water quality due to the contaminants transfer between river and aquifer. The water movement within this particular environment can be influenced by geology, topography, land use, climate, etc., being an essential component o...

Lengthening periods between precipitation have been recorded and we can see a change in the distribution of rain over time. An increased number of these phenomena has also been confirmed by the IPCC. Due to this change in the redistribution of rainwater and the impact of high urbanization, sewerage systems are affected. The problem of a high number of impermeable areas is also associated with a high degree of urbanization. During torrential rains in combination with impermeable surfaces, the time of outflow into t...

The article is about three hydrological river routing models (RRM) implemented in Bulgaria, coupled to a land surface model (LSM), mainly for flood forecasting purpose. For the evaluation of the three RRMs the authors use a river basin of Mediterranean climate - the Varbitsa River with catchment area of 1200 km2. The river is prone to dangerous flash floods because of their fast propagation. LSM SURFEX (Surface Externalisee) but formally the integrated part ISBA (Interface Soil Biosphere Atmosphere) is used to com...

The paper presents a calculation of an annual balance between the water inflow and discharge in the Cheboksary hydrosystem reservoir. The calculation is implemented in MathCad. The calculation is based on the principle of identifying the main areas of water use and water consumption, including hydroenegetics, water transport, drinking and industrial water supply, fishery, and recreation. Characteristics of water inflow and discharge by the Cheboksary hydrosystem are calculated. A positive annual balance of the wat...

Glina Station is a project for the treatment of wastewater from the sewerage of Bucharest. The sewerage of the entire city has always flowed into the Dambovita River. Currently, only partially Stage I is carried out, through which the mechanical treatment of about 60% of the city's wastewater is carried out. The paper presents a solution for biological pretreatment of wastewater to validate the use of ultraviolet waves for biological disinfection but also for the treatment of specific non-synthetic pollutants from...

If the place hydrogeological conditions are uniform (invariable aquifer transmissivity, no impact of hydrogeological network) then the quarry depression cone and the pumping rate for the quarry draining can be obtained by using analytical methods. The dolomite aquifer at the Iecava district in Latvia included large impervious areas. Due to this fact, appliance of analytical methods cannot give the right depression cone. The local hydrogeological model (HM) was applied for obtaining the depression cone of the dolom...

The article analyzes the need of a suitable velocity field creation in the cross section profile of the fish pass, which would generate velocity variability for the occurring ichthyofauna with different swimming abilities. In this way, is not only the condition for the maximum vertical velocity fulfilled, but also parts of the profile with slow-flowing water in the bank zone are formed. There are also others recommendations as top width of the water level, doped discharge or recommended longitudinal slope of the f...

Floods are natural phenomena which cannot be prevented. In order to avoid and reduce the adverse impacts of floods for human health, the environment, cultural heritage and economic activity it is important to provide flood risk management plans. Development of flood risk management plans under Directive 2007/60/EC are elements of integrated river basin management. For the implementation of Directive 2007/60 / EC, Member States need to carry out a preliminary flood risk assessment based on available or readily deri...

The devastating impact of floods in the past years triggered the awareness and interest regarding the need of effective flood risk management and improved strategies. The spatial distribution of the elements at risk, which are represented by land use inventories, is an important factor that influence the cost associated with floods, the rapid urbanization leading to an increased flood exposure and vulnerability. The land use planning can be a useful tool for flood damage mitigation and must be taken into account i...

One of the most important components of monitoring any object is to determine the degree of its pollution. Current and accurate information on the quality of water bodies and soils is the basis for regulating the activities of water users and land users, ensuring measures for the rational use of natural resources, informing the relevant authorities and the population about possible dangerous situations. Surface waters, like agricultural households, are strategic renewable natural resources of Ukraine. A characteri...

Acid tar lagoons (ATLs) are a common source of groundwater pollution in industrialized countries worldwide. Even after recultivation, the spatial extent of the residual environmental pollution from such lagoons is often unknown, as the monitoring of groundwater is mostly done in discrete locations ? monitoring wells. Shallow surface geophysical methods, such as ground penetrating radar (GPR) and electrical resistivity tomography (ERT) are often used in monitoring groundwater and soil contamination. The greatest va...

This report is a case study on use of Electrical Resistivity Tomography (ERT) alongside other methods to have a better understanding of surface depressions and their formation in gypsum karst region of Latvia. Study territory is well known gypsum karst region. It is a relatively flat area with up to 5m thick Quaternary cover overlaying Upper Devonian Salaspils Formation gypsum sediments. Previous studies have identified several sinkhole formations in the area. Remote sensing methods like analysis of Digital Elevat...

The lack of direct measurements (the most accurate way to determine characteristic high flows) has posed the need to look for other hydrological methods that are sufficiently reliable. The regionalization is an indirect hydrological approach for specific high flow determination used at ungauged river stretches. Usually the hydro-technical constructions or other important economic activities connected to the water use are the main reason necessitating the study of characteristic high water on rivers. For the purpos...

Droughts are a natural phenomenon with a fairly high frequency worldwide. Their evolution generates, through the water deficit, a state of vulnerability at the level of natural and social components. In areas dependent on groundwater resources this vulnerability is transformed in a high social and economic risk. In this situation can be included the eastern part of Romania where over 50% of the population, predominantly in rural areas, is supplied with groundwater. In order to highlight the negative effects of a n...

The researches were carried out in a catchment with a pronounced torrential character and flood risk (Slanic catchment) located in the Siret catchment, Romania. Precipitation data were available from the monitoring network of the Siret Water Basin Administration, from 2019 and 2020; given their continuity they were considered suitable to allow hydrological modeling. A hydrological modeling was followed, that simulates the rain-drainage processes of the water systems, given that in the studied catchment there are a...

The increasing world population demand for bioeconomy products intensify the nitrogen cycle and encourage eutrophication in water bodies. Global climate change and land use transformation have a significant impact on the hydrological cycle. Integrated water management in the catchment area is a sustainable solution for catchment area development and balancing economic and environmental interests. The aim of this study is to develop an optimization model for sustainable lake management. The case study is done in eu...

The article is dedicated to the study of hydrometeorological parameters on a stationary oceanographic platform in the Black Sea. The research paper contains the description developed in the Marine Hydrophysical Institute’s complex for measuring meteorological parameters (wave height, wind speed and direction, free-air and sea temperature, barometric pressure, relative humidity). The measurements were carried out on a stationary oceanographic platform located in the coastal zone of the southern coast of Crimea at a...

At present, surface runoff represents serious environmental problems in the urban environment, causing adverse effects on socio-economic and natural systems. Surface runoff is a complex source. The creation of surface runoff is described by various hydraulic hydrological processes, from the impact of water on the surface to the mouth into the sewer network or recipient. The formation of the precipitation-runoff process depends on several factors. Land-use change is a key factor that significantly affects the quali...

In this study SURFEX land surface model is used coupled to RAPID river routing model in order to investigate the influence of alternative ground and rooting depth, soil texture and land cover maps on the ability of the coupled system to adequately simulate the river flow in Upper Arda River basin in Bulgaria. This was done by comparing the statistical scores of computed from the model data series against measured streamflow discharge series: that is scores of simulations using former soil texture maps from Harmoni...

Regions with scarce freshwater resources, such as North Africa and the Middle East, face significant challenges today and will face even greater challenges in the future as a result of socioeconomic and climatic changes. The Missour Oases in Morocco is one of many arid Moroccan Ocases grappling with increasing water scarcity, which threatens self-sufficiency in agriculture. Efficient water management is required to sustain people's livelihoods. The main aim of this study is to assess the impact of human activities...

Within twelve months, comprehensive studies were conducted on the effect of full-scale climatic tests on the properties of 30HGSA steel’s samples were carried out with full immersion in water at the mouth of the Don River (the basin of the Sea of Azov) at two stations (Station 1 & Station 2). The water area where the experiment was carried out is characterized by a complex combination of fresh, slightly saline and brackish waters, which affects the structure of communities of aquatic organisms. The article shows t...

The number of standards that are included in the individual management systems standards (MSSs) is gradually rising. Standards are significantly related by common and specific requirements, both, for manufacturers and service providers. A special area of service provision is the drinking water supply. This paper aims to introduce a simplified application process of integrated management systems (IMSs) through visual management. The two standards used in a model, which is defined as a complex duplet, are Quality Ma...

The fact of interaction of calcium silicate with the key elements present in the spent nuclear fuel is established. Nanopowders of synthetic calcium silicate with a given particle size 10, 2 and 0.6 microns were obtained. It was found experimentally that a decrease in the particle size of the calcium silicate powder contributes to an increase in its sorption properties (distribution coefficients and static exchange capacity). If for uranium static exchange capacity in the considered range of powder particle sizes ...

Ensuring sustainable water supply, in particular in agriculture, requires knowledge of the local hydrologic cycle and up-to-date assessment of the water resources, determined by the new requirements of agricultural holdings water demand for irrigation and the level of irrigation infrastructure, especially in drought. The aim of the present work is to offer an informed solution for water use management in a pilot irrigation system. The study has been carried out by a balance method through a computer program for co...

As a response for water losses in urban water supply networks, the pressure management has become now, one of the most effective method in order to reduce the leakage part of non-revenue water (NRW). The implementation of pressure management has as main objectives besides reducing leakage, reducing bursts frequency and extending the life of the infrastructure. Therefore, in order to improve the water distribution systems, this paper presents the advantages of pressure control and optimization for water distributio...

The article analyzes the influence of operation on all structures downstream the stream on the water content and dryness in the stream. As area of interest was chosen the catchment of a small stream in the foothill region with a gauging station and several water structures built on this stream in the last century. Seven structures with the most significant impact were examined. Multiple reconnaissance of the terrain and structures were performed, in different time periods; the existing operational manuals of water...

Municipalities can take various measures to prevent damage from extreme rainfall events like increasing the dimension of the combined sewer system, separate them into foul and storm sewer systems, increase the infiltration capacity of the subsoil by reducing the (poorly permeable) paved surface, increase the infiltration surface in (underground) facilities or increase the permeability of the paving, install green / blue roofs to ensure delayed drainage and evaporation of water to the atmosphere or by building stor...

The article presents the issue of scale deposits in sanitary installations. Scale contributes to improper operation of sanitary devices and leads to their degradation. Scale build-up in pipes and measuring elements results in higher water consumption due to inaccurate estimation of this resource consumption. The consequence is that devices based on process automation do not work properly due to disturbances in the actual water flow. The formation of deposits also leads to economic and ecological losses, as sanitar...

The Volga is a cascade of lowland reservoirs since 1982. This allows flood prevention, river-sea navigation and hydropower generation. The creation of a cascade of hydropower plants led to the flooding of fertile floodplain lands, a decrease in water quality, and drastic algal blooms in the summer season. The alternative solution includes establishment of combined renewable energy plants containing floating solar and pumped storage plants near the existing hydropower plants. This is tentatively estimated to lower ...

Building of a shopping center was planed in Riga city, Latvia. Unfortunately, the center was located in the former dump site place where the about eight meters thick waste body contained an irregular mixture of oil products, Phenols, Detergents and metals: Copper, Lead and Chromium. It was presumed that these dissolved in groundwater contaminants should enter the nearby lake and dich. It was found out that cleaning of the place was not time and cost effective. It was necessary to reduce the concentration of these ...

The Volga River is essentially a cascade of reservoirs that provide hydroelectric energy. This technical solution made it possible to produce electricity for industrialization, to ensure the passage of river-sea vessels between five seas and to stop floods on the Volga River. Although often considered a green energy source, there are environmental and economic considerations that should be accounted for in a holistic and sustainable perspective, i.e. a life cycle of ca. 50 years, areal inundation by reservoir wate...

Romania faces floods every 2-3 years, followed by human and animal losses, and large flooded agricultural areas. There are rivers such as Siret, Crisul Repede, Cri?ul Negru, Ialomita with non-rehabilitated areas that have systematically caused damages in the last decade. Based on the latest measurements, the real transport capacity of natural course in high flow conditions and flood risk was estimated. In recent years, after the massive floods recorded in 2005, 2008, 2012, and 2018, there have been uncontrolled de...

Sewerage networks form an integral part of urban infrastructure. It is necessary to reconsider the outdated concept of sewer networks and rainwater management in cities that do not meet sustainable development ideas. The new understanding of rainwater management needs to be adapted to the new environmental conditions caused by climate change. The occurrence of pluvial floods has recently become an increasingly common phenomenon. The reasons are outdated sewer networks, rapid urbanization, an increase in impervious...

Many studies confirm a shift to warmer climate in South East Europe. In Bulgaria, warming trends have been registered since the end of the last century, and different scenarios show increased air temperatures in the future. In the face of climate change, it is a challenge to assess its effect on water resources. The aim of the paper is to evaluate the possible impact of climate change on the discharge of two springs from the Lovech-Tarnovo karst basin. This study uses the monthly water balance method to compare th...

National statistic is the most important tool for gathering information. It helps us to be analyzed on the national and local level. As a vital resource statistical information for water is the most important for predicting its supply and demand. Another aspect of water analysis is water using for both industrial and household purposes. Last but not least is water wastage. All of these aspects are vital for the Bulgarian cases because of information lack. Last year Bulgaria was faced with big water problems all ar...

Crimea is a water-stressed region with intermittent spatial and temporal distribution of water resources. Water demand covers by reservoirs, fields of pumping wells, and taping springs. Groundwater resources of the region are estimated as 1216 thousand m3/d or 0.54 L/sec/km2, in the Crimean Mountains ? 1-2 L/sec/km2, so they are concentrated in a relatively small area. Methods to increase water supply, like conjunctive use of surface and groundwater, managed artificial recharge, seawater desalination, are used in ...

An explanation is given of the regularities of occurrence of constant constituents in long-term series of river runoff, evaporation, and changes in the total water reserves of catchments, which are based on the detection effect, both in hard-deterministic and in stochastic systems – river basins. With regard to long-term runoff, this conclusion is confirmed by empirical data on the probability distributions of almost all the rivers of the globe. For evaporation and changes in the total water reserves, this conclus...

Karezes represent a sustainable water supply since their discharge is regulated by the natural groundwater renewal in the mountains and on upslope surfaces in the valleys. Although most karezes have become inactive due to lowered groundwater levels, they can still be used together with other accessible information sources to initially and remotely interpret basin geohydrology and the groundwater resources when they were constructed (and today if still active). This is mainly done by using karezes to map the depth ...

Peat fires in drained bogs are now becoming more active and large-scale, which poses a great threat to humans and the environment. The projects for secondary watering of drained zones are difficult and require improved methods for their implementation. Space monitoring is the most effective technique to assess the preliminary results and develop recommendations to further projects for the entire area of the bog. Analysis of remote sensing data since 1970 of the southwestern part of drained Orshinsky moss bog in Tv...