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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...

Pesticides are intensively used for the protection of field crops, orchards and vineyards, but they are also used in the removal of undesirable stands on non-agricultural land (railway embankments, playgrounds, handling areas, etc.), in water management (in coastal management, destruction of growths in irrigation canals), in forestry, etc. Regular application of pesticides increases their content in the aquatic environment and agricultural products. Their occurrence in water is relatively common and it follows tha...

Construction of water-reservoirs across the rivers flowing into the sea often much complicates the coast protection problems. The reason is deficit of filling sediment on the coast-protecting beaches, which settle under the water. Consequently, two problems arise: efficiency of water-reservoir decreases and coastlines start to degrade what eventually ends with coast washing away and disaster. Main goal of is to develop the method of efficient solution of water-reservoir and coastal problems allowing maintaining th...

The purpose of mathematical modeling of runoff flow in sewer networks is to assess the hydraulic capacity and monitor their behavior in different conditions to predict the future state. Models of sewer networks are part of the design process. Their advantage is the possibility of simulating the future state of the network and the precipitation and runoff process in the context of climate change. With the help of simulations, it is possible to anticipate future conditions in the river basin and thus effectively des...

Urban floods, which are most often caused by intensive rainfall and the fast formation of surface runoff, cause great damage to the urban population and infrastructure. Due to the stochastic (random) nature of precipitation, it is not entirely possible to achieve reliable operation of sewer systems. We can only try to design and operate them in the most reliable way. Urbanization and changes in climatic conditions are one of the main factors for increasing the frequency of flash and rain floods in urban conditions...

Soil water content and understanding water dynamics is crucial for agricultural practice. Direct measurements of the soil moisture are being slowly replaced by the mathematical simulations and models. One of the most used models for the simulation of the soil moisture is the HYDRUS 1D model, which simulates how the water is transported through or within the soil profile. The soil water model HYDRUS can simulate water movement through a porous media during transient (irrigation) and steady state (between irrigation...

The development of urban areas, transport, and technical infrastructure is one of the natural phenomena that have been going on for several centuries. In recent years, due to migration population in many developed countries occurs a rapid increase of impervious areas in urban agglomerations. The rapid development of an impervious surface can cause changes in the hydrological and climatical characteristics of the area. As a result of these changes, surface runoff is creating. Surface runoff is an area source of pol...

Modeling is important for river system analysis and management. The aim of the research is to apply disaggregation models to data with recovered natural river flow of Osam River located in North Bulgaria. As a result river discharge synthetic sequences are generated on monthly and seasonal discretization. We want to test applicability of the models for specific climatic, hydrological and orographic conditions in Bulgaria. Disaggregation models are from the family of stochastic models. Disaggregation models could b...

Most of the suspension matter transported by rivers derives from the riverbed erosion. Complementary, the anthropogenic factor is responsible for the introduction of significant amounts of sedimentary material, especially suspended, but also dissolved material. In most cases, the distinction between naturally occurring materials and anthropic ones is almost impossible to achieve due to the complexity of the erosion processes. The suspended sediments concentration (SSC) and discharges were analyzed in the Danube De...

Land reclamation is an improvement of land, which reduces the adverse effects of climate conditions and ensures the sustainable use of natural resources. Latvia is in humid soil area, which means that soils are formed under wet conditions. During the spring and autumn, these soils are wetted and unsuitable for land treatment. The installation of drainage systems shall ensure the reception of excess humidity and its removal from agricultural land, which makes it possible to process the land and to carry out economi...

Balanced development of ecosystem services in regions is one way of achieving the UN's sustainable development goals. Ecosystem services are divided into three main groups: First delivery services. Nature supplies us food and drinking water, raw materials and alternative energy sources. Thanks to natural biodiversity, we can grow a variety of vegetables and fruit, gather berries and mushrooms in the woods, and fish in the sea, rivers and lakes. Nature also supplies drinking water, which is the source of life for e...

The Danube-Black Sea Channel, inaugurated in 1984, although it has a dark history, is also of significant importance at European level, being the third longest navigable channel in the world, after the Suez Channel and the Panama Channel and connects the North Sea to the Black Sea through the Rhine-Main-Danube Channel, shortening the route of goods transport from Australia to Central Europe by 400 kilometers. The channel has a total length of 95.6 km and consists of two branches, a main one having 64.4 km long and...

The study aims to determine the environmental and resource potential of the river basins of the Crimean Peninsula. Given its unique hydrological and geomorphological features, the territory of Crimea was divided into a grid of soil and water protection design units in terms of operations and areas, which is comprised primarily of basins of 4th order (following the Horton-Strahler classification system). For the study area, a geographic database based on cartographic materials, remote sensing data, global digital r...

The main objective of the study was to estimate the level of shallow well water pollution and the impact of natural and anthropogenic factors on it and to use the research results for the prognosis of the pollution level and the reduction of pollution. The subject research is water of shallow wells. Analysis of the shallow well water quality has been carried out in Lithuania, Kaunas region, in 83 shallow wells. Wells situated in Pypliai village were chosen for a more detailed examination. Shallow wells are usually...

In many cities from Romania, the water supply systems are very old, sometimes having over 60 years after their commissioning. Under these conditions, permanent large leakages are recorded. They are significant for the operator, influencing its economic performance and operating costs. The water supplier must understand the mechanism of water leaks and their influence on the performance of distribution network. The losses recorded by the system are unused for the purpose for which the supply was made, representing ...

Changing climate variability and the type of land use are the main factors influencing the hydrological regime. The hydrological regime of the lake has a direct impact on biodiversity and has an impact on socio-economic processes in areas adjacent to the lake. The aim of the study is to predict and assess the impact of climate change and the change in the type of land use on the hydrological regime of Lake Usma. Two linear land-use change scenarios were used for modelling. Twelve climate scenarios were used to mod...

The variation in time and space of the groundwater level is conditioned by the variation of climatic parameters. In the current context in which climate change is characterized by periods of prolonged drought and the distribution of precipitation is of the rainfall type, with large amounts of precipitation in a very short time, the groundwater level has accentuated periods of consumption to the detriment of accumulation episodes. In a first phase, the high values of the temperature superimposed over the periods wi...

The case is considered when at the Koknese district in Latvia the hydrogeological situation for dolomite excavation quarries is heterogeneous. The place geological build is complex and the quarries are situated close to large surface water bodies represented by the Daugava river and by the Urgu reservoir. The depression cones of the quarries were obtained by using the local hydrogeological model (HM). The primary data for creating the local HM were provided by the regional HM of Latvia LAMO4. The Groundwater Vista...

The purpose of the scientific research is the development, improvement and implementation of information technologies for a comprehensive assessment of the intensity and nature of anthropogenic pressure on urban (urbanized) water resources by contact and remote methods to improve the efficiency of the environmental management system and the environmental safety of the water fund of cities. The tasks for conducting research carried out using technologies for remote sensing of the Earth from space (ERS), specialized...

Here, we report a laboratory experiment performed with the water from the Don river. Our aim was to examine the effect of NH4VO3 in concentrations of 0.5, 5, 25, and 100 ?g/L of Vanadium (V) on the phytoplankton growth indicators in the absence of their growth limitation by Nitrogen (N) and Phosphorus (P), as well as on the metabolism intensity indicators of plankton communities: biochemical oxygen demand (BOD5) and alkaline phosphatase activity (APA). The stimulating effect on the phytoplankton abundance and biom...

Substances of petroleum origin that reach groundwater limit water use and can have irreversible effects on ecosystems interacting with them. Quantitative changes in groundwater and synergistic effects generated by petroleum products on ecosystems can be objectively quantified based on a scenario for the transport of pollutants concentrations through the aquifer. In this sense, with the help of mathematical models, the research estimates the spatial and temporal dimension of a possible accidental pollution by petro...

Water ecosystems of Arctic region are most vulnerable to modern climatic changes, since global biogeochemical processes mostly occur on territories of permafrost zone. This work gives new insights into fundamental research question of how fast organic matter of thawing permafrost can be converted to greenhouse gases which are emitted into the atmosphere (for example, CH4). We aimed to identify microbial response and associated release of CH4 from Arctic lakes in response to temperature increase. We investigated la...

The paper studies theoretical and experimental issues of improving scour protection facilities of oil trunk line underwater passages. External influences on the stability of oil trunk line underwater passages were analyzed. Based on the analysis results, the impact of hydraulic processes on riverbed deformations in the underwater passage of the Surgut-Polotsk oil trunk line was evaluated. Also automated calculations of hydraulic and riverbed effects of the bottom soil scour in the Mathcad application environment w...

Flash flood is a very dangerous type of flood that can happen with little or no warning. The flash floods becoming more frequent in the territory of the Slovak Republic, typically for last decades in Central Europe. The number of responses of regional Fire & Rescue Corps connected to the flash floods is very high nowadays. Extreme weather fluctuations due to climate change are threatening drinking water sources as well as new types of natural threats. Severe storms and tornadoes are expected to occur more frequent...

Water quality was investigated in Lake Matita, part of the Danube Delta Biosphere Reserve, Romania, to assess the overall status of the freshwater ecosystem, in accordance with the EU Water Framework Directive (WFD ? 2000/60/EC), which addresses all surface waters i.e., rivers, lakes, transitional waters and coastal waters in the EU. From this perspective, a specific physical and chemical analysis of surface water samples was performed, collected in different sectors of the lake, during the summer of June 2020. Se...

Applicability of rainfall-runoff models to the river conditions in temperate climate is tested. Different deterministic models were examined with distributed and semi-distributed parameters. Finally, two models have been selected from US Army Corps of Engineers - Hydrologic Engineering Centre: HEC-GeoHydrological Modeling System (HEC-GeoHMS) and HEC-Hydrological Modeling System (HEC-HMS). Hydrological study for selected Bulgarian watershed is presented. The populated and urbanized area of Yantra River basin is con...

This article presents the results of studies of the hydrodynamical and sedimentological conditions of the Sulina Channel, the middle distributary of the Danube within its delta. One field campaign (at low waters) in September 2019 was conducted to analyse the geometry, the sediment composition and hydraulic conditions of the channel. During the field campaign, the measured water mean velocity was from v = 0.01?0.54 m.s-1 for a water discharge (measured upstream, at the bifurcation, knot Ceatal St. George) of 698 m...

The incidence of extreme rainfall has increased in recent decades. This negative impact of climate change also calls attention to when dealing with the recovery and reconstruction of sewer networks. Slovak cities have built a combined sewer network, which in the event of heavy rainfall, is not able to fulfill their primary function. The pipes are not able to carry the large volume of mixed wastewater, and network overload occurs. This paper focuses on the assessment of individual collectors of the sewerage network...

The updating of the used inflow data to the reservoirs from Annex 1 of the Water Act has been developed for the needs of the Ministry of Environment and Water (MoEW) and for the annual schedules of their water use. Monthly inflow with a certain probability of exceedance (PE - 50%, 75%, 95%) were estimated. The results of the development are uploaded to the MoEW website(https://www.moew.government.bg).In the report are presented and new unpublished results of the annual security assessments - annually inflows with ...