Search

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 quality and quantity of surface runoff. In addition, the quality of surface runoff is also influenced by precipitation characteristics and air quality. In the last few years, the air quality is significantly worsened. The reason for this is the rapid development of urban areas, transport, and technical infrastructure. As a result of these phenomena, excessive gases, particularly carbon dioxide, methane, sulfur dioxide, and nitrous oxide, were produced. Due to many research, emission in the atmosphere accounts more than 50 % of atmospheric precipitation pollution. In recent decades, attention has been paid to rainwater quality due to the water crisis. The current use of large amounts of quality water and the removal of heavily polluted water causes significant damage to the aquatic ecosystem. Given the facts, the paper focuses on analyzing the quality of surface runoff captured in urban areas. Subsequently, a comparison of the influence of air quality on the quality of surface runoff is performed. The study results could help design the proper management of surface runoff in urban agglomerations concerning environmental protection and the possibility of rainwater reuse. [ABSTRACT FROM AUTHOR]

The objective of this paper is to present time and space analysis of drought occurrence in the agricultural regions in Slovakia. It considers the most important natural environment factors influencing the occurrence, duration and intensity of this phenomenon. The analysis of the occurrence of meteorological and agronomic drought was performed for the period 1961 - 2014. The results detect the importance of dealing with the problem of drought in Slovakia. Drought occurred every year during investigated period except in 1965 and 2010 at least in a part of Slovakia. The performed analyses identify the increased intensity of drought. The paper compares two approaches to drought identification. From the results obtained it could be evaluated, that there exist various limitations, when drought (especially agricultural drought) is evaluated using climatic indices (Standard Precipitation Index was used in this paper) and much more comprehensive results were gained using the DAISY agro-ecological model, which also considers soil properties and the water requirements of plants. [ABSTRACT FROM AUTHOR]

Climate extremes affect directly social and ecological systems. Therefore, extreme climatic indices based on daily precipitation as well as maximum and minimum air temperatures have been derived. A detailed analysis of extreme precipitation patterns is essential for the development of monitoring and mitigation strategies.The analysis of eight precipitation-related extreme climatic indices (annual total precipitation (PRCPTOT), heavy precipitation days (R10), very heavy precipitation days (R20), very wet days (R95pTOT), maximum 1-day precipitation (RX1day), simple daily intensity (SDII), maximum 5-day precipitation (RX5day), and extremely wet days (R99pTOT)) are presented in this paper using data from three Hungarian meteorological stations (Budapest, Debrecen and Szombathely) for the period from 1960 to 2010. There is no significant difference in SDII, R10, R20 and R95pTOT indices at any of the analyzed stations. The RX1day and RX5day indices indicate increasing values at Budapest station after 1990. Similarly, the R99pTOT index had increased values at Budapest station for the period 2000–2010. The PRCPTOT values slightly decreased at Budapest and Szombathely stations in the entire period 1960–2010. [ABSTRACT FROM AUTHOR]

On 18/19 June 2016, the manifestation of two severe supercell thunderstorms in the northern half of Moldavia caused unexpected losses exceeding 14 mil. EUR. Radar estimated hail sizes over 10 cm were recorded over large areas. On the ground level there was recorded hailstones with a diameter greater than 5 cm in some areas. This day’s situation was exceptional due to the synoptic context. There was a strong link between the low-pressure area centered over Southeastern Europe and the formation of a trough (a fusion between a mobile Icelandic Cyclone located with its center over Scandinavia and the Mediterranean low-pressure systems.). As a consequence of this pressure pattern a moist and tropical air advection occurred in our region, going SV, which entered the territory already, sensitized by storms and precipitation excess and by the air much cooler from NV with dynamic features suggesting good conditions for hailstorms to form. In this paper, we investigate the severe hailstorm on the 18th of June from a different appoint of view. By using and combining available observational data sets, the objective is to reconstruct the whole event at a very high resolution and to examine the conditions that are most relevant for convective initiation and the further development of the organized convective cell. Using a series of photos of damaged objects, the aim is to relate different object classes and hailstone sizes. In order to locate the hail swath, we had to use the radar reflectivity from DWSR Doppler C band with a 0.5º elevation to calculate hail kinetic energy and to separate the storm nuclei containing only rain from those which also contained hail. Relations between radar-derived intensity and damage frequency are derived on the basis of Emergency Inspectorate from Iasi counties, which have been massively affected by the storm. This analysis also argues the need to extend the National Hail Suppression System to agricultural areas in the eastern part of Iasi County. [ABSTRACT FROM AUTHOR]

Cut-off low altitude cyclones (COLs) are characterized by the presence of small cold air masses detached from the polar vortex as a consequence of Rossby waves development. Their displacement at a lower latitude is capable to induce higher atmospheric instability and they have a great influence on the amount of precipitation over Romania between April and September. This paper is based on the analysis from a synoptic point of view of the days when the precipitation amount was greater than 10 mm between 1961 and 2010, during the warm semester (April - September). Sea level pressure maps from Deutsche Wetterdienst and 500 hPa geopotential height from Climate Forecast Systems of NOAA, available at www.wetter3.de, the GFS forecasting numerical model (Global Forecast System) were used for the synoptic analysis. This study, by analyzing all days with the amount of rainfall greater than 10 mm, and by making all the cartographic materials presented, aims to highlight the most affected areas by them, using ROCADA dataset. Out of the total of 5,340 days with the precipitation amount greater than 10 mm at the level of Romania, 1498 of them (28%) are associated with COLs activity. In April, 74 days (4.94%) with COLs activity were found. Starting May, the COLs activity is much better evidenced, being present in 220 days (14.69%), in June 408 days (27.24%) and 437 days in July (29.17%). In August, with 252 days (16.82%) and in September with 107 days (7.14%), the COLs activity started to decrease. [ABSTRACT FROM AUTHOR]

Climate change and its impact on the environment is an urgent problem of the present time, causing hydrological changes and ecosystem change. As a result, formed ecosystem representing less valuable in economic terms, low productivity. Therefore, study of climate change is an important and urgent task. Global climate changes in the South part of Russia is reflected in the warming of the winter period and an increase in the amount of precipitation during the cold season. This paper analyzes the changes in meteorological conditions in Rostov region and its influence on water regime of the Lower Don. Rostov region is located in the Western subdomain of the Atlantic-continental steppe region, temperate zone. The climate of the region is moderate continental, formed under the influence of air mass transfer from the Atlantic, meridional Northern and southern transfers and transformation of air masses. Flat terrain favors the flow of air masses of different origin. The river flow is formed in the steppe zone. Spring flood depends on soil moisture and moisture reserve in the catchment area. The total water content of the river depends on the amount of winter precipitation and air temperature. The main flow (60 - 65%) formed by meltwater in the spring, 25-30% - through underground supply and 3-5% at the expense of atmospheric precipitation. River is characterized by high and long spring flood. In natural conditions, it accounts for about 70% of annual runoff. Tsimlyanskoe reservoir smoothed seasonal distribution of runoff. Until 1952, spring floods accounted for 78% of runoff and 22% for the rest of the year. After the launch of the reservoir, the situation changed. Only 47% the flow of the river falls in the spring. The rivers of the Don basin are now experiencing a decrease in spring runoff. At the same time, there is an increase in summer, autumn and winter runoff in comparison with the period of climatic norm. Analysis of the annual distribution of runoff led to the allocation of two periods: before the construction of the Tsimlyansk reservoir and after the start of operation. Since 2007, there has been a constant decrease in the water content of the river, which lasted until 2016, the low-water regime. [ABSTRACT FROM AUTHOR]

In the first part of the paper is characterized, catchment Somes Mic, from point of view the hydro morphological and morphometric. Because of much diversified relief specific to this drainage basin, the atmospheric precipitation are uneven and in varying amounts on catchment surface. Further, the paper presents the hydrologic analysis of atmospheric precipitation and liquid runoff in the catchment for 2010. For estimation of the character' excedentar of the flow of liquids in the studied area, was determined the discharge coefficient. Finally the paper presents the conclusions and some considerations on water resources management from catchment Somes Mic. [ABSTRACT FROM AUTHOR]

The paper deals with the definition of the zones of influence of dangerous factors on regime observations for the aquifer in karst areas on the basis of experimental research in the area of recreation at the lake Big Holy Nizhny Novgorod region. On the basis of the geological section of the study area and the chemical analysis of groundwater, zones and objects with anthropogenic impacts on the aquifer identify. For the control of the aquifer in the recreation center information-technical complex of the geo-ecological monitoring of groundwater are used on the basis of multi-frequency method vertical electric sounding. The method is designed to detect changes in salinity and the level regime of the aquifer in the territory of decentralized water supply. The zones lesion study area by karst processes from route observations defined. In paper justified that at the control of the quality of the groundwater by geoelectric methods corrective amendments in the model parameters of the geodynamic models to introduce necessary. On the basis of the data revealed a previously unrecognized hazard, that are associated with unorganized leisure travelers. They use recreational resources of the lake, forming unauthorized places dumps of organic and inorganic content of the waste. When the spring flood period in areas of karst surface water and groundwater are accumulated, contaminants are infiltrated with the surface water precipitation and fall in ground water, changing their chemical composition, and increasing the overall mineralization. [ABSTRACT FROM AUTHOR]

The paper analysis the precipitations associated to the cut-off lows and their regional distribution induced by the air circulation types and the position of cut-off lows in relation to the different regions of the country, in Romania in 2014. Cut-off lows have been identified using geopotential, air temperature and circulation maps at 500 and 300 hPa levels within the region of latitude 40 to 50 °N and longitude 15 to 35 °E. To establish the atmospheric circulation type for each cut-off event, HYSPLIT model was used (Draxler and Rolph, 2012). Based on the daily precipitation data for the year 2014 from 150 meteorological stations from Romania, divided into historical and geographical regions, the total amount of precipitation for each cut-off low event was determined. It was also calculated the monthly and annual amount of precipitation for each weather station and the ratio between the monthly (and annual) amount of precipitation and those associated to the cut-off lows. The most important findings are: 13 cases of cut-off lows were identified, the highest number in July (3 cases); in most of the cases the cut-off lows lasted for 2 days (5 cases), the longest case having 8 days; the most significant amounts of precipitation were recorded in May and April, and the highest value recorded exceeded 100 mm (125.7 mm in Banat region); masses of air reach in moisture advected from the south (S, SV, SE) and west (V, NV), recorded a high frequency; high percentages of precipitations induced by cut-off lows from the total rainfall of the year were recorded in the regions situated in the south, east, south-west and west part of Romania as a consequence of air circulation types generating cut-off lows existence. [ABSTRACT FROM AUTHOR]

The paper analyzes the frequency and trend of the rainfall amounts of the rainy periods lasting 2, 3 and 4 days, which occurred at 4 weather stations in MaramureŠ County, in the period 1961-2016. The homogeneity of the daily data set has been analyzed, using the methodology described by Wijngaard et al. (2003), based on Pettitt, Standard normal homogeneity, Buishand and von Neumann tests, at the 99% significance level and for the frequency analysis, HYFRAN software was used. Subsequently, the frequency of the precipitation amounts of the mentioned periods was calculated, using the method of equal intervals. The cumulative amounts in 2-day intervals show the highest frequency for Class 1 (0.2-6.5 mm), with a probability of occurrence of 45-55%, the cumulative amounts in 3 days for Classes 1 (0.4-7.4 mm) and 2 (7.5-14.5 mm), with a probability of 22-37%, and the cumulative amounts in 4 days for Class 2 (9.9-17.8 mm), with a probability of 21-30%. The decadal distribution of periods accumulating exceptional amounts of precipitation, ≥50 mm, was then analyzed and it was established that the maximum risk interval of their occurrence is June-September. The frequency, trend, degree of assurance and variability of the maximum annual rainfall quantities of the mentioned periods were also studied. The return periods of maximum annual rainfall quantities registered in 2-4 days are ranging between 29.8 and 580 years. [ABSTRACT FROM AUTHOR]

Last year (2017) was one of the three hottest years on record, with many high-impact events including catastrophic hurricanes and floods, debilitating heat waves and drought. Long-term indicators of climate change continue unabated and arctic sea ice coverage remained below average. Of the hottest years on record, 15 out of 17 have come since 2000. By contrast, more than a century has gone by since the planet had a record cold year (1911). At European level, based on the three different observational records of global average annual near-surface (land and ocean) temperature, 2007-2016 decade was 0.87 to 0.92 °C warmer than the pre-industrial average, which makes it the warmest decade on record. Of the 17 warmest years on record, 16 have occurred since 2000. In Romania, the mean annual air temperature rose by 0,6°C in the last 100 years. The evolution by decades of the mean multiannual air temperature over the 1901-2015 period show that the increasing trend is obvious especially beginning with 1991, 2015 being the warmest year of the records. This paper will make an analysis of 2006 - 2015 decade climate (using temperatures and precipitations records for western part of Romania) using several drought indices. [ABSTRACT FROM AUTHOR]

In different climatic and hydrological regional studies, data from grid databases that cover the climatic data of larger areas can be used. The authors of this contribution are interested in the region of Central Europe, where they can use the publicly available CarpatClim and ECA&D databases for such needs. The first mentioned database provides better spatial detail of the data, but the data is available only to the year 2010. On the other hand, the EC&D database is continually updated (up to the present), but the spatial detail in which it provides data is lower. This paper discusses the possibility of extending the time range of the CarpatClim climate data with help of the ECA&D database to the present. The data conversion was done using regression methods that will be described in more detail in the article. The authors also tested the usability of the Random Forest algorithm for this purpose. The quality of such data extrapolation was evaluated by the Pearson correlation coefficient R, which for the most problematic and consequently the least correlated climatic data, i.e., precipitation, has an average value of 0.91. For the best-correlated data, i.e., temperatures, the degree of accuracy determined by R is higher than 0.95. [ABSTRACT FROM AUTHOR]

The precipitation survey by modern techniques helps calculate the amount of rainfall in the catchment and save it in a digital format. This paper proposes the development of a GIS methodology for determining the input data or parameters needed for modelling the rain-drainage process in order to anticipate the amount of available leakage water and the integration of slopes leakage to estimate the magnitude of rapid floods that may occur. The data obtained from the rain-gauge stations in the Uz catchment are used in the present study to calculate the average rainfall on the ccatchment by means of classical calculation methods but also with the help of the GIS program, by zoning the catchment and applying the Thiessen polygons method, respectively for generating the average precipitation map on the catchment. The generation of Thiessen polygons using GIS is a new, fast and accurate approach for average rainfall calculations, thus obtaining raster data can help implementing the average rainfall map, being helpful in subsequent applications for automatic parameter extraction. [ABSTRACT FROM AUTHOR]

The paper presents the method for model formation to describe the maximum rainfall depth for practical applications. The precipitation models presented in the paper can be a comprehensive solution to the problem of input data for designing and testing the hydraulic capacity of sewer systems in hydrodynamic modeling. For description of precipitation phenomena, the following distributions were used: Gumbel (Maximum Extreme Value Type 1), Fréchet (Maximum Extreme Value Type 2) and Weibull (Maximum Extreme Value Type 3) distribution. The estimates of the parameters of the density function were determined by maximum likelihood method. The probability distributions were evaluated by the Anderson-Darling test, in order to determine the best one. [ABSTRACT FROM AUTHOR]

Over the past decade, the widespread concern about the staggering effects of climate change, particularly in the agricultural sector, has become very serious. It has been agreed that the inter-annual, monthly and daily distribution of climate variables such as temperature, radiation, precipitation, water vapour pressure in the air and wind speed affects a number of physical, chemical and biological processes that drive the productivity of agriculture. Thus, understanding the possible consequences of climate change in agriculture matters for designing adaptation policies intending to minimise negative consequences and maximise positive effects. This research study aims to identify and evaluate risks in agriculture in the context of climate change. The results of this research study reflects the forecasts of the changing climate and the following effects to agriculture and summarises the political framework of assessing and mitigating climate change and the risks related to it. The paper also describes the impact of agriculture on the national economy and characterises social and economic values of this sector. Overall, the evaluation shows that agriculture is affected by a set of risks that may not be very high individually, but can cause serious damage to crop yields if a certain combination of the risks occurs. [ABSTRACT FROM AUTHOR]

The area of the CSA mine is situated at the northern edge in the central part of the Most Basin (North Bohemia, The Czech republic). The interesting area, currently represented by the internal wastedump and the own openpit mine CSA, has undergone significant changes over time that are associated almost with coal mining activities. This activity hit especially hydrological and hydrogeological conditions of the area. The original surface was naturally drained by the several streams, which were necessary translate to artificial flows due to the developing of coal mining. In the interesting area were located a considerable amount of natural reservoirs, the largest was lake Drinov (Komorany). The presented area is divided into several hydrogeological units, which are characterized by mutually diferent major determinants, such as morphology, lithological charakteristice of the main types of rocks, tectonic disorders etc. The submitted paper describes the changes in the hydrological and hydrogeological conditions in the interesting area that occur during the exploitation of brown coal deposit and their impact on the mining operations in the openpit mine CSA. [ABSTRACT FROM AUTHOR]

Climate change is one of the most important economic, social and environment challenges facing humanity, the impact of climate change depends on the vulnerability of different economic and environment sectors. Agriculture is one of the sectors affected by increasing temperature and changing precipitation regime. The paper aims to identify and assess the types of the climate change impacts on water resources in agriculture and to propose measures for adaptation in order to provide resources and to optimize production. In this context, the adaptation to climate change in agriculture is an objective of the Romania climate change strategy. [ABSTRACT FROM AUTHOR]

This paper analyzed the spatial and temporal variability of the rainy periods that occurred in the county of Maramureş. In this regard, daily precipitation data have been used from 4 weather stations, for the period 1961-2013. In the first stage the homogeneity of the daily data set has been analyzed, based on Pettitt, Standard normal homogeneity, Buishand and von Neumann tests, at the 1% significance level. The analyzed data belonged to Class 1 („useful"), as they reject the null hypothesis of 3 out of the 4 mentioned tests. Subsequently, the annual, monthly and seasonal number of rainy periods has been analyzed, the length of the periods, their frequency depending on length and their spatial and temporal variability. Based on the CurvExpert 1.37 program, the trend of the annual number of rainy periods depending on their duration was studied. The result was a total number of over 8100 periods, for the 4 stations. The number of rainy periods increases from the west to the east, once with the growth of land altitude. During a year may occur, on average, between 37-40 periods with an average length of 4-4.5 days. The length of the rainy periods varies between 2-35 days. The most periods are recorded in the intervals May-July and December-January. The most periods lasting ≥ 10 days, occurred in the decade 2001-2010 or 1961-1970. [ABSTRACT FROM AUTHOR]

Climate is defined as the "average weather" in a place and it includes patterns of temperature, precipitation (liquid or solid), humidity, wind and seasons. Climate patterns play a fundamental role in shaping natural ecosystems, and the human economies and cultures that depend on them. Climate change is a change in the statistical distribution of weather patterns when that change lasts for an extended period of time. Climate change is happening considering that temperatures are rising, rainfall patterns are shifting, glaciers and snow are melting etc. Many forecasts indicate that these changes will continue, and that extreme weather events resulting in hazards such as floods and droughts will become more frequent and intense. Climate change is an additional pressure on ecosystems, leading to northward and uphill shifts of many plant and animal species. It negatively impacts agriculture, forestry, energy production, tourism, and infrastructure in general. Generally, when we discuss about the impact of climate change, we firstly talk about water. Water is a vital component of our environment and society being directly affected by the changes in precipitation and temperatures patterns. This paper will analyze the climate changes in the area of Timis County (Romania) since 1994 thus realizing an analysis for the last 20 years. [ABSTRACT FROM AUTHOR]

Our paper presents the impact of the use of aluminum salts - as a tool for the rehabilitation of water bodies - on the changes of selected environmental conditions in lakes with low water alkalinity. The method for the lakes restoration with aluminum or iron coagulants called phosphorus inactivation is widely used for more than 30 years. The main objective of this method is precipitating excess phosphorus into insoluble compounds unavailable to algae. However, these coagulants are usually acidic in nature, which limit their use in lakes susceptible to pH changes. Therefore there is a need to look for ways to optimize restoration treatments in this type of lakes. Field examinations were conducted in five small (5-30 ha) lakes affected with moderate anthropopressure, characterized by a low alkalinity (0.5-2.5 meq/dm³) and varying reaction (pH 5,7-8.5), localized in the Masurian Lake District (Poland). In each lake four experimental mesocosms were placed, in which aluminum coagulant were introduced in varied dose (used as polyaluminum chloride - the most commonly phosphorus sorbent in the full-scale restoration projects). The duration of the experiments (2 years) allow determining the long-term response of ecosystems to the restoration treatments. The in situ fragmentary-technical scale results showed that the use of the tested coagulant strongly affects the level of pollution of lakes with organic matter and it is clearly correlated with the dose of used salt. The study discussed the impact of physicochemical conditions of water, including changes in pH on the effectiveness of the water purification process from an excess of organic impurities by coagulation. The results indicate that the application of aluminum coagulants with optimized dose can be an effective and safe method of water purification in the natural, soft-water reservoirs which are susceptible to acidification. [ABSTRACT FROM AUTHOR]

The paper deals with estimation of spatial and temporal variability of magnitude and number of statistically significant coefficients of correlation between components of chemical compound of atmospheric precipitation in the North of the Russian plain. There is direct relationship between magnitude of correlation coefficients and chemical composition of atmospheric precipitation. For example, in space aspect the greatest number of significant correlation coefficients meets on coastal and city continental weather stations. Finally, in temporal (seasonal) aspect this regularity is observed in May, i.e. ion concentration increases in the air during the season of photochemical activity. [ABSTRACT FROM AUTHOR]

Changes in temperature and precipitation and their impact have been studied worldwide. In this paper, the Black Sea western coast including Bulgarian, Romanian and a partially Ukrainian coastline was considered. The study is focused on the analysis of the trends in annual and seasonal precipitations at a regional scale over 48 yrs (1961-2008). Data sets recorded in 13 weather stations were analyzed: eight Bulgarian stations, 4 Romanian stations and one Ukrainian station. The main goal was to find changes in precipitation using Mann-Kendall and Sen's slope methods. The main findings are: during winter and spring decreasing trends prevails, while during summer and autumn increasing trends are dominant; for annual amounts there is no homogeneous trends, but the slopes in northern part are stronger, whereas seasonal slopes are stronger in the South of the area [ABSTRACT FROM AUTHOR]

Soil water erosion is one of the most dangerous degradation process which influences the soil fertility as well as the other important soil properties. This fact brings up need to more detailed research of erosive factors. One of these factors is rainfall erosivity factor (R). There are a lot of methodologies which calculate this factor and they depend on the data availability. The aim of this paper is to compare these different methodologies and evaluate their impact on the final value of rainfall erosivity factor. We compared equations which calculate only with annual precipitation data (equation designed by Šabata, Holý etc.) with modified methodology of Wishcmeier- Smith. The results showed that equations which calculate only with annual precipitation are several times higher than results obtained with modified Wischmeier-Smith methodology. These significant differences invoke the question if the applied anti-erosion measurements are adequate, because values of rain factor which are used in our conditions are significantly lower than calculated values with using of both methodologies. [ABSTRACT FROM AUTHOR]

In this paper, we consider the oscillations of the water level of Ohrid lake as a hydrological feature. The data are measured from the measurement station for water level in Ohrid. We analyze the average (maximum and minimum) annual water levels from 1924 to 2005 year. Missing data for a few years are replaced by mean of suitable decade. Regarding whole period 1924-2005, we found that the linear trend is decreasing, although it is increasing or constant for some decades. Also, using cluster analyses we classify the years according closeness of water level. [ABSTRACT FROM AUTHOR]

The significant increase of precipitation in Slovakia after the long dry period 1981-1994 has a direct relation to the incidence of floods after 1996. Over the past 10 years (2000-2010), the amount of precipitation in Slovakia was by almost 150 mm higher than in 1981-1990. The year 2010 was the wettest one during the last century. The aim of this paper is to briefly summarize the historical floods that occurred in Slovakia. The systematic instrumented hydrological observations were initiated mostly in the second half of the 20th century. The available relatively short time series of water stages or discharge can provide an insight into neither extreme floods with long return periods, nor the significant changes in their frequency and changes in the intra-annual distribution of runoff. Such information may be of importance for risk assessment of both - floods and droughts. Therefore, it is necessary to reach for other data sources as well. The evaluation of the design values (N-year flood) from the series of annual discharge maxima from the instrumented era resulted in an underestimation of the flood risk. Data on floods before the instrumented era can be obtained by analyzing related natural data - so called paleofloods, or various documents and historical sources (flood signs, annals of the cities and villages) - so called historical floods. From our analysis confirms that the flood of 1813 was one of the most significant floods on the territory of Slovakia over the past 250 years. [ABSTRACT FROM AUTHOR]

Droughts rank first among all natural hazards when measured in terms of the number of people affected. Drought is the most complex but least understood of all natural hazards. It is broadly defined as "severe water shortage". Northern Africa is one of the most arid areas of the world, with rainfalls that vary widely in terms of both temporal and geographical distribution. Libya just like most parts of North Africa is facing drought. Statistical analysis for time series can reveal possible trends in time. For drought risk analysis it is very important to study the historical climate parameters (temperature and precipitation) to know if there is a trend, downward or upward. The aim of this paper is an investigation of the trends by using statistical methods, exactly non-parametric Mann-Kendall test, in these parameters because they have a strong correlation and are related with drought. [ABSTRACT FROM AUTHOR]

Mining activities for underground and surface extraction of useful minerals generate a change in local hydrostatic levels, requiring the drainage of the resulted water. Owing to water contact with the existing mineralization, mine waters are generally loaded with suspended material and heavy metal ions and have an acid pH. The mine waters continue to be polluting factors for that area and for water courses, even if the mining activity is closed. Therefore is particularly important to study the limitation of polluting effects of mine waters and if possible, the recovery of useful metals from them. The paper goal is to present the characteristics of mine waters from Certej mining area, the suitable techniques for mine water cleaning and finally, some results of a first research stage, applying a method of mine water treatment based on the co-precipitation of heavy metal ions with lime. The research has revealed the conditions in which heavy metal ion content decrease can be realized in order to meet the quality conditions for waters discharged in natural receptors. Except the lead ions (that have the content within the allowed limits) the efficiency of heavy metal ion content reduction was of over 93%, in the determined working conditions. It has been established the requirement for the flocculent dosage and consumption in the precipitate decantation phase and the aeration of clean water, to reduce its alkalinity under the allowed limit (pH=8.5). [ABSTRACT FROM AUTHOR]

The last years presented in Romania large variations regarding the temperatures and precipitations regimes. The western part of this country (which includes and the Banat region) was affected by floods and droughts, phenomenon which followed at very short periods of time. All of these phenomenon's can be understand as results of climatic changes. Due to its past hydrological situation, large areas from Banat region are covered by land reclamation and improvement areas, unfortunately part of them with an improper regime of work. These systems had an important role in facing the effects of climatic changes. Unfortunately still persist the menace of different water crisis situations; result of human's activities in the large frame of climatic changes. This paper will present graphs and maps representing different climatic indicators which were computed using different programs. [ABSTRACT FROM AUTHOR]

Droughts rank first among all natural hazards when measured in terms of the number of people affected. Northern Africa is one of the most arid areas of the world, with rainfalls that vary widely in terms of both temporal and geographical distribution. Libya just like most parts of North Africa is facing drought. Statistical analysis for time series can reveal possible trends in time. For drought risk analysis it is very important to study the historical climate parameters (temperature and precipitation) to know if there is a trend, downward or upward. The aim of this paper is an investigation of the trends by using statistical methods, exactly non-parametric Mann-Kendall test, in these parameters because they have a strong correlation and are related with drought. [ABSTRACT FROM AUTHOR]

Daily precipitation data measured in 38 meteorological stations during all months of the year in the period (1960 - 2009) are sorted looking for consecutive days with precipitation. The used 38 points are approximately uniformly located on the territory of the country (19 in North Bulgaria and 19 in South Bulgaria) and represent in fact the basic (synoptic) stations in the meteorological network of the National Institute of Meteorology and Hydrology. Fifteen cases of extreme number of consecutive days with precipitation (>15 days) are revealed on the territory of the country during the examined 50-years period. These cases represent exceptionally rare events with a great return period and form a relatively small but obtained through a sort of an enormous volume of data sample that is a good basis for an interesting and significant analysis of the examined rare phenomenon. The obtained results concerning the distribution of the revealed extreme cases over territory, during the years, by seasons and months, and according to the precipitation type amount are summarized in the paper together with the common features of the corresponding synoptic situations. The proposed investigation is a part of a greater research aiming to reveal the spatial - temporary regime of the number of consecutive days with precipitation over Bulgaria and the corresponding typical synoptic situations together with the eventual climatic variations of this regime and their relation to the drought events in the country. [ABSTRACT FROM AUTHOR]

Dojran Lake is the smallest natural lake in Macedonia, but is very important water resource for population in the region. Main economy in the region is tourism and fishery. Dojran Lake with its hydrological basin is a closed hydrological system with natural inflow of water to the lake, but no natural outflow. Recharge of the lake is from direct surface and underground inflow. In the period 1988-2000, the water level in the lake continuously was declining. Water level declination caused ecological catastrophe for the flora and fauna in the lake and lake's basin. In 2002, the Republic of Macedonia finished a project to build a system for bringing water from Gjavato wells near Vardar River with capacity of 1 m /s. The water level in the lake has recently increased. The reasons for changing the water level in the lake are not clearly identified, and they are located in hydrological conditions or uncontrolled usage the water from the lake. In order to define the causes of changes in the lake requires detailed hydrological and meteorological analysis. This paper will present the results of mathematical-statistical analysis on the basis of historical data of measured water level, precipitation, and air temperature from hydro-meteorological stationNew Dojran for the period 1961-2008. [ABSTRACT FROM AUTHOR]