Karakteristike naglih poplava malih rijeka planinskog Krima

The maximal surface runoff from territory of the Crimean Mountains is represented as a runoff of small rivers that flow through the western and eastern part of the northern slope and from the southern coast. The materials from 54 water gauging stations (WGS) were used to characterize the maximum runoff during rain and meltwater-rain floods on the rivers in the Crimean Mountains. A modified reduction structure of a calculation formula was used for valuation of the maximal runoff of different origin flash flood for rivers at the Mountainous Crimea. The main parameters of the proposed model are summarized as dependencies on the average height of the catchments and generalized in the form of a map. It is also possible to use the second variant of the suggested method taking into account the factor of underlying surface is introduced. Comparison of the calculated values of maximal runoff shows good convergence with both the initial information, and the largest values in the observation period.Maksimalno površinsko otjecanje s područja krimskih planina prikazano je kao otjecanje malih rijeka koje teku kroz zapadni i istočni dio sjeverne padine te s južne obale. Podaci 54 vodomjerne postaje (WGS) korišteni su za opisivanje maksimalnog otjecanja tijekom riječnih poplava uzrokovanih kišama i topljenjem snijega na krimskim planinama. Modificirani oblik redukcijske formule korišten je za procjenu maksimalnog otjecanja pri naglim poplavama rijeka u planinskom području Krima. Glavni parametri predloženog modela mogu se prikazati u ovisnosti o prosječnoj nadmorskoj visini sliva u formi karata. Druga mogućnost predložene metode je uzimanje u obzir same podloge. Usporedba izračunatih vrijednosti maksimalnog otjecanja konzistentna je s inicijalnim podacima i s najvećim vrijednostima u promatranom razdoblju

Probabilistic-forecasting method for determination of low flow discharge of Pivdennyi Buh, Black Sea area, and Lower Dnieper rivers

The aim of the study is to substantiate the probabilistic-forecasting method for forecasting the low flow discharge and its implementation for the Pivdennyi Buh, Black Sea area and Lower Dnieper rivers, taking into account climatic patterns of precipitation distribution and establishing probabilistic characteristics of low flow discharge in multi-year period. The study area is in a zone of significant risk due to the shortage of water resources, the formation of extremely low runoff in the dry flow period, which requires its definition and forecasting. The methodological basis of forecasts is to solve the equation in determining the components of the low flow of rivers by constructing regional dependences for forecasting the average decade summer-autumn low flow from previous water discharge (in runoff modules), establishing their probabilities water discharge for a number of intakes. Results. The paper substantiates the probabilistic-forecasting method for forecasting low flow discharge (in summer, autumn and winter periods) based on the construction of regional dependences of average decadal runoff modules on previous water discharge for groups of basins of studied rivers taking into account climatic dependences of precipitation distribution in the territory and the establishment of probabilistic characteristics of the low flow water discharge in a multi-year period. The methodology of territorial short-term forecasts of average decade water discharge of low flow of summer, autumn and winter river runoff is assessed as satisfactory with a margin of error of 70 % to 97 %, with a number of members of more than 500 points. To determine the cumulative probability of the forecast values of the average decade water discharge of the summer, autumn and winter dry weather flow, the empirical distribution of the average monthly water discharge in the limited seasons, which are generalized in the basins of the studied rivers of Ukraine, is established. Scientific novelty. For the first time for the zone of insufficient natural water content of rivers the method of territorial forecasts of low flow discharge, determination of their probability of occurrence in a multi-year period and cartographic representation of prognostic values have been developed and practically implemented. The practical importance is the use of forecast modules maps of low flow for spatial monitoring and assessment of low water levels on rivers in the whole region, including ungauged rivers, and their probabilistic characteristics – to assess the possible occurrence of low runoff, even when it reaches values close to the environmental runoff, which are critical for the functioning of the river ecosystem

Megafloods in Europe can be anticipated from observations in hydrologically similar catchments

Megafloods that far exceed previously observed records often take citizens and experts by surprise, resulting in extremely severe damage and loss of life. Existing methods based on local and regional information rarely go beyond national borders and cannot predict these floods well because of limited data on megafloods, and because flood generation processes of extremes differ from those of smaller, more frequently observed events. Here we analyse river discharge observations from over 8,000 gauging stations across Europe and show that recent megafloods could have been anticipated from those previously observed in other places in Europe. Almost all observed megafloods (95.5%) fall within the envelope values estimated from previous floods in other similar places on the continent, implying that local surprises are not surprising at the continental scale. This holds also for older events, indicating that megafloods have not changed much in time relative to their spatial variability. The underlying concept of the study is that catchments with similar flood generation processes produce similar outliers. It is thus essential to transcend national boundaries and learn from other places across the continent to avoid surprises and save lives

Дослідження повторюваності катастрофічних весняних водопіль на території України

Introduction. In the period of global and regional climate change in almost all the regions of our planet there is an increase in cases of extreme natural phenomena, which definitely include floods of various origin. Over the past decades, according to the Centre for Research on the Epidemiology of Disasters (CRED), in many countries of the world there has been a record high number of natural disasters which affected about 2.7 billion people, that is more than one third of the world's population.The purpose of article is to analyze historical data and study the current state and trends in the frequency of catastrophic floods.Methods. To estimate the trends in the chronological series of the maximum runoff of rivers the methods of statistical analysis and spatial generalization have been used.Results. On the basis of literature sources and taking into account current data, frequency of flooding in the period from 900 to 2010 in the territory of Kyivan Rus and modern Ukraine has been estimated. Analyzing the results obtained, it can be noted that the largest number of floods was observed in the period from 1501 to 1600 years (11 cases), from 1601 to 1700 years (13 cases), and in the modern period from 1901 to 2000 (10 cases); 900-1000 and 1701-1800 years can be considered as the periods with the smallest number of cases. Since the beginning of the new millennium catastrophic and high floods have been observed in Europe almost every year. In order to estimate the repeatability of catastrophic floods at the rivers in Ukraine, the chronological series of the maximum runoff of spring water have been made up in accordance with the data of hydrological stations, which have the largest and preferably continuous periods of observations from their beginning until 2015 inclusive. The analysis has shown that in Ukraine the spring floods in 1932 and 1970 are classified as catastrophic. The analysis of trends in the chronological series of annual maxima in conditions of climate change showed their heterogeneity across the territory of Ukraine: on the left bank of the Dnieper and in the Siverskyi Donets basin there is a tendency towards earlier periods of snowmelt and the occurrence of the spring floods, and on the other territory, on the contrary, there is a tendency of increase in cases of winter floods instead of the spring high water.The scientific novelty of the study is determined by the use of observational data up to 2015 inclusive, and its practical significance is determined by the opportunity to use the results when justifying hydrotechnical projects in order to minimize the consequences of catastrophic floods on rivers.В статье приведены результаты анализа исторических данных о выдающихся паводках и половодьях катастрофического характера, оценена их повторяемость в историческом контексте и на современных данных. Показано, что как по данным отечественных ученых, так и по результатам оценок международных организаций (Centre for Research on the Epidemiology of Disasters, World Meteorological Organization), для территории Украины наибольшая повторяемость опасных природных явлений (51,9%) приходится на паводки различного происхождения. Проанализированы наиболее длительные временные ряды максимального стока весеннего половодья на равнинных реках Украины, выполнено описание катастрофических, многоводных и маловодных половодий. Выполненный анализ подтвердил возможность отнесения половодья 1932 и 1970 годов в категорию катастрофических по масштабу территории, которые они охватывали. В частности, половодья 1932 года отмечено в бассейнах Днепра, левобережье Днестра, Южного Буга и Северского Донца, а в 1970 году - практически по всей территории Днепра, а также на реках Приазовья. В целом же наиболее многоводными за длительный период наблюдений, как по общему объему весеннего стока, так и по максимальным расходам воды половодья в Украине формировались в 1932, 1942, 1947, 1956, 1960, 1963, 1970, 1971, 1978, 1979, 1980, 1986, 1988, 1994, а маловодные весны приходились на 1944, 1950, 1954, 1962, 1965, 1969, 1975, 1976, 2007, 2008, 2009, 2014, 2015 рр. Анализ тенденций в рядах годовых максимумов в условиях изменений климата показал их неоднородность по территории Украины, а именно на левобережье Днепра и в бассейне Северского Донца наблюдается тенденция к более ранним датам снеготаяния и прохождения половодья, в то время, когда на остальной территории наоборот – наблюдается тенденция к увеличению случаев зимних паводков вместо весенних половодий.В статті представлені результати аналізу історичних даних про визначні паводки і водопілля катастрофічного характеру, оцінено їх повторюваність в історичному контексті і на сучасних даних. Показано, що як за даними вітчизняних вчених, так й за результатами оцінок міжнародних організацій (Centre for Research on the Epidemiology of Disasters, World Meteorological Organization), для території України найбільша повторюваність небезпечних природних явищ (51,9%) припадає на паводки різного походження. Проаналізовано найбільш тривалі часові ряди максимального стоку весняного водопілля на рівнинних річках України, виконано опис катастрофічних, багатоводних і маловодних водопіль. Проведений аналіз підтвердив можливість віднесення водопілля 1932 та 1970 років до категорії катастрофічних за масштабом території, які вони охоплювали – так водопілля 1932 року відмічене в басейнах Дніпра, лівобережжя Дністра, Південного Бугу та Сіверського Дінця, а 1970 року – практично за всією територією басейну Дніпра, а також на річках Приазов’я. В цілому ж найбільш багатоводними за тривалий період спостережень, як за загальним об’ємом весняного стоку, так і за максимальними витратами води водопілля в Україні формувалися у 1932, 1942, 1947, 1956, 1960, 1963, 1970, 1971, 1978, 1979, 1980, 1986, 1988, 1994 рр., а маловодні весни припадали на 1944, 1950, 1954, 1962, 1965, 1969, 1975, 1976, 2007, 2008, 2009, 2014, 2015 рр. Аналіз тенденцій у рядах річних максимумів в умовах змін клімату показав їх неоднорідність за територією України, а саме на лівобережжі Дніпра та в басейні Сіверського Дінця спостерігається тенденція до більш ранніх дат сніготанення та проходження водопілля, в той час, коли на решті території навпаки – наявна тенденція до збільшення випадків зимових паводків замість весняних водопіль

Megafloods in Europe can be anticipated from observations in hydrologically similar catchments

Megafoods that far exceed previously observed records often take citizensand experts by surprise, resulting in extremely severe damage and loss oflife. Existing methods based on local and regional information rarely gobeyond national borders and cannot predict these foods well because oflimited data on megafoods, and because food generation processes ofextremes difer from those of smaller, more frequently observed events.Here we analyse river discharge observations from over 8,000 gaugingstations across Europe and show that recent megafoods could have beenanticipated from those previously observed in other places in Europe.Almost all observed megafoods (95.5%) fall within the envelope valuesestimated from previous foods in other similar places on the continent,implying that local surprises are not surprising at the continental scale. Thisholds also for older events, indicating that megafoods have not changedmuch in time relative to their spatial variability. The underlying conceptof the study is that catchments with similar food generation processesproduce similar outliers. It is thus essential to transcend national boundariesand learn from other places across the continent to avoid surprises andsave lives.</p

Megafloods in Europe can be anticipated from observations in hydrologically similar catchments

Megafloods that far exceed previously observed records often take citizens and experts by surprise, resulting in extremely severe damage and loss of life. Existing methods based on local and regional information rarely go beyond national borders and cannot predict these floods well because of limited data on megafloods, and because flood generation processes of extremes differ from those of smaller, more frequently observed events. Here we analyse river discharge observations from over 8,000 gauging stations across Europe and show that recent megafloods could have been anticipated from those previously observed in other places in Europe. Almost all observed megafloods (95.5%) fall within the envelope values estimated from previous floods in other similar places on the continent, implying that local surprises are not surprising at the continental scale. This holds also for older events, indicating that megafloods have not changed much in time relative to their spatial variability. The underlying concept of the study is that catchments with similar flood generation processes produce similar outliers. It is thus essential to transcend national boundaries and learn from other places across the continent to avoid surprises and save lives

Impact of water stress on Mediterranean oak savanna grasslands productivity: Implications for on-farm grazing management

The new scientific decade (2023-2032) of the International Association of Hydrological Sciences (IAHS) aims at searching for sustainable solutions to undesired water conditions–whether it be too little, too much or too polluted. Many of the current issues originate from global change, while solutions to problems must embrace local understanding and context. The decade will explore the current water crises by searching for actionable knowledge within three themes: global and local interactions, sustainable solutions and innovative cross-cutting methods. We capitalise on previous IAHS Scientific Decades shaping a trilogy; from Hydrological Predictions (PUB) to Change and Interdisciplinarity (Panta Rhei) to Solutions (HELPING). The vision is to solve fundamental water-related environmental and societal problems by engaging with other disciplines and local stakeholders. The decade endorses mutual learning and co-creation to progress towards UN sustainable development goals. Hence, HELPING is a vehicle for putting science in action, driven by scientists working on local hydrology in coordination with local, regional, and global processes

The IAHS Science for Solutions decade, with Hydrology Engaging Local People IN a Global world (HELPING)

International audienceThe new scientific decade (2023-2032) of the International Association of Hydrological Sciences (IAHS) aims at searching for sustainable solutions to undesired water conditions - may it be too little, too much or too polluted. Many of the current issues originate from global change, while solutions to problems must embrace local understanding and context. The decade will explore the current water crises by searching for actionable knowledge within three themes: global and local interactions, sustainable solutions and innovative cross-cutting methods. We capitalise on previous IAHS Scientific Decades shaping a trilogy; from Hydrological Predictions (PUB) to Change and Interdisciplinarity (Panta Rhei) to Solutions (HELPING). The vision is to solve fundamental water-related environmental and societal problems by engaging with other disciplines and local stakeholders. The decade endorses mutual learning and co-creation to progress towards UN sustainable development goals. Hence, HELPING is a vehicle for putting science in action, driven by scientists working on local hydrology in coordination with local, regional, and global processes