45 research outputs found

    Transportation of sediment carried during flood events in a small urban catchment

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    The aim of this study is to present results of investigations into rainfall–runoff–suspended sediment transport process, based on field measurements conducted in small (A = 28.7 km2) urban catchment of Służew Creek, located in Warsaw. Hydrological monitoring was carried out by the Department of Hydraulic Engineering at the WULS-SGGW (Warsaw University of Life Sciences). Between 2014–2017, twelve flood events were recorded, during which rainfall, discharge, turbidity, and suspended sediment concentrations were measured. The correlation between the flows and sediment concentration was analysed and dextrorotary hysteresis for all events was indicated, meaning that sediment concentrations during the increase of water flows were higher than at the same flow values during the fall of the flood wave. Also first flush effect has been noted, that is, most of the sediment loads was washed-off at the beginning of the flood event; whereas the peak concentration occurred prior to the maximum discharge. Statistically significant correlation between direct runoff and suspended sediment has been established

    Long-term changes of hydrological variables in a small Lowland watershed in Central Poland

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    Climate-induced changes in small watersheds are still not well researched because long-term datasets are usually missing for these watersheds. Such studies can, however, improve our understanding of the watershed response to climatic changes at such a small scale being transparent. In this study, we investigate trends in temperature, precipitation and river-flow characteristics in a small watershed, typical for Central Poland, with 53 years of observations (1963–2015) using the Mann-Kendall test. Particularly, we examine whether any trends in hydro-meteorological variables can be identified, and if any associated changes in water resources in this region can already be observed. We found that this short period already allows for detecting some changes in hydro-meteorological variables. These changes could be characterized by a significant increase in the mean annual air temperature on a daily basis, and a significant decrease in the mean annual discharge on a daily basis and in the minimum annual discharge on a daily basis. Yet, no significant trend could be detected for the total annual precipitation, the maximum summer rainfall, and the maximum annual discharge on a daily basis. These findings indicate that water resources are decreasing in this region, which affects natural habitats, agriculture and local communities

    Climatic and anthropogenic drivers of zero-flow events in intermittent rivers in Poland

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    River intermittence was studied based on data from hydrological monitoring in Poland. We screened the entire state database and two another data sources applying the criterion for zero-flow event: discharge less than 0.0005 m3s1m^{3}∙s^{–1}, and found five intermittent rivers with catchment area from 9.2 to 303.7 km2km^{2}. We aimed at finding associations between intermittence and climatic driving forces (temperature and precipitation), and between intermittence and anthropogenic activity. We used the Spearman correlation coefficient, circular statistics, and statistical tests for trend. The concentration of zero-flow days, mostly in summer, and the decreasing trend in the standardised precipitation evapotranspiration index (SPEI) in all catchments at various aggregation levels, and an increasing trend in the total number of zero-flow days and in the maximum length of zero flow events in two rivers, were detected. The strong negative correlation (-0.62 ≤ ρ < 0) between intermittence and the SPEI backward lagged in time showed that intermittence resulted from prolonged deficits in climatic water balance due to increasing evapotranspiration. The reaction of the Noteć catchment, amplified by the anthropogenic pressure (brown coal mines), was reflected in the atypical shape of the rose diagram and in inhomogeneities in river discharges. The results show that the rose diagram can serve as an indicator of the degree of anthropogenic impact on runoff conditions

    Monthly Rainfall Erosivity: Conversion Factors for Different Time Resolutions and Regional Assessments

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    As a follow up and an advancement of the recently published Rainfall Erosivity Database at European Scale (REDES) and the respective mean annual R-factor map, the monthly aspect of rainfall erosivity has been added to REDES. Rainfall erosivity is crucial to be considered at a monthly resolution, for the optimization of land management (seasonal variation of vegetation cover and agricultural support practices) as well as natural hazard protection (landslides and flood prediction). We expanded REDES by 140 rainfall stations, thus covering areas where monthly R-factor values were missing (Slovakia, Poland) or former data density was not satisfactory (Austria, France, and Spain). The different time resolutions (from 5 to 60 min) of high temporal data require a conversion of monthly R-factor based on a pool of stations with available data at all time resolutions. Because the conversion factors show smaller monthly variability in winter (January: 1.54) than in summer (August: 2.13), applying conversion factors on a monthly basis is suggested. The estimated monthly conversion factors allow transferring the R-factor to the desired time resolution at a European scale. The June to September period contributes to 53% of the annual rainfall erosivity in Europe, with different spatial and temporal patterns depending on the region. The study also investigated the heterogeneous seasonal patterns in different regions of Europe: on average, the Northern and Central European countries exhibit the largest R-factor values in summer, while the Southern European countries do so from October to January. In almost all countries (excluding Ireland, United Kingdom and North France), the seasonal variability of rainfall erosivity is high. Very few areas (mainly located in Spain and France) show the largest from February to April. The average monthly erosivity density is very large in August (1.67) and July (1.63), while very small in January and February (0.37). This study addresses the need to develop monthly calibration factors for seasonal estimation of rainfall erosivity and presents the spatial patterns of monthly rainfall erosivity in European Union and Switzerland. Moreover, the study presents the regions and seasons under threat of rainfall erosivity.JRC.H.5-Land Resources Managemen

    Mapping monthly rainfall erosivity in Europe

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    Rainfall erosivity as a dynamic factor of soil loss by water erosion is modelled intra-annually for the first time at European scale. The development of Rainfall Erosivity Database at European Scale (REDES) and its 2015 update with the extension to monthly component allowed to develop monthly and seasonal R-factor maps and assess rainfall erosivity both spatially and temporally. During winter months, significant rainfall erosivity is present only in part of the Mediterranean countries. A sudden increase of erosivity occurs in major part of European Union (except Mediterranean basin, western part of Britain and Ireland) in May and the highest values are registered during summer months. Starting from September, R-factor has a decreasing trend. The mean rainfall erosivity in summer is almost 4 times higher (315MJmmha-1h-1) compared to winter (87MJmmha-1h-1). The Cubist model has been selected among various statistical models to perform the spatial interpolation due to its excellent performance, ability to model non-linearity and interpretability. The monthly prediction is an order more difficult than the annual one as it is limited by the number of covariates and, for consistency, the sum of all months has to be close to annual erosivity. The performance of the Cubist models proved to be generally high, resulting in R2 values between 0.40 and 0.64 in cross-validation. The obtained months show an increasing trend of erosivity occurring from winter to summer starting from western to Eastern Europe. The maps also show a clear delineation of areas with different erosivity seasonal patterns, whose spatial outline was evidenced by cluster analysis. The monthly erosivity maps can be used to develop composite indicators that map both intra-annual variability and concentration of erosive events. Consequently, spatio-temporal mapping of rainfall erosivity permits to identify the months and the areas with highest risk of soil loss where conservation measures should be applied in different seasons of the year

    Foto-obrazy architektury: Fotografia jako medium referujące i projektujące architekturę

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    Praca recenzowana / peer-reviewed paperNiniejszy zbiór prac teoretycznych, fotoesejów i kronika studenckich konkursów fotograficznych organizowanych od 2008 roku na Wydziale Architektury i Sztuk Pięknych Krakowskiej Akademii im. Andrzeja Frycza Modrzewskiego, ma być zapisem refleksji związanych ze specyficzną, jak dotąd mało zbadaną a wszechobecną częścią teorii architektury, jaką jest fotografia. Jej szczególna odmiana ściśle związana ze sztuką budowania jest określana mianem fotografii architektonicznej, jednakże niniejsza monografia nie została tą definicją ograniczona.This book contains a selection of theoretical works and photo essays as well as a chronicle of photo competitions organised in the Faculty of Architecture and Fine Arts at Andrzej Frycz Modrzewski Krakow University since 2008, which is meant as the record of thoughts related to the specific, omnipresent though little examined so far, realm of the theory of architecture, i.e. photography. Its specific variant closely related to the building practice is called architectural photography. This monograph, however, is not restricted by means of the said definition and attempts at a slightly broader description of the phenomenon, reaching beyond its boundaries.Monografia powstała w ramach projektu badawczego nr WAiSP/DS/4/201

    Trends in flow intermittence for European rivers

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    Intermittent rivers are prevalent in many countries across Europe, but little is known about the temporal evolution of intermittence and its relationship with climate variability. Trend analysis of the annual and seasonal number of zero-flow days, the maximum duration of dry spells and the mean date of the zero-flow events is performed on a database of 452 rivers with varying degrees of intermittence between 1970 and 2010. The relationships between flow intermittence and climate are investigated using the standardized precipitation evapotranspiration index (SPEI) and climate indices describing large-scale atmospheric circulation. The results indicate a strong spatial variability of the seasonal patterns of intermittence and the annual and seasonal number of zero-flow days, highlighting the controls exerted by local catchment properties. Most of the detected trends indicate an increasing number of zero-flow days, which also tend to occur earlier in the year, particularly in southern Europe. The SPEI is found to be strongly related to the annual and seasonal zero-flow day occurrence in more than half of the stations for different accumulation times between 12 and 24 months. Conversely, there is a weaker dependence of river intermittence with large-scale circulation indices. Overall, these results suggest increased water stress in intermittent rivers that may affect their biota and biochemistry and also reduce available water resources

    PESFOR-W: Improving the design and environmental effectiveness of woodlands for water Payments for Ecosystem Services

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    ABSTRACT: The EU Water Framework Directive aims to ensure restoration of Europe?s water bodies to ?good ecological status? by 2027. Many Member States will struggle to meet this target, with around half of EU river catchments currently reporting below standard water quality. Diffuse pollution from agriculture represents a major pressure, affecting over 90% of river basins. Accumulating evidence shows that recent improvements to agricultural practices are benefiting water quality but in many cases will be insufficient to achieve WFD objectives. There is growing support for land use change to help bridge the gap, with a particular focus on targeted tree planting to intercept and reduce the delivery of diffuse pollutants to water. This form of integrated catchment management offers multiple benefits to society but a significant cost to landowners and managers. New economic instruments, in combination with spatial targeting, need to be developed to ensure cost effective solutions - including tree planting for water benefits - are realised. Payments for Ecosystem Services (PES) are flexible, incentive-based mechanisms that could play an important role in promoting land use change to deliver water quality targets. The PESFOR-W COST Action will consolidate learning from existing woodlands for water PES schemes in Europe and help standardize approaches to evaluating the environmental effectiveness and cost-effectiveness of woodland measures. It will also create a European network through which PES schemes can be facilitated, extended and improved, for example by incorporating other ecosystem services linking with aims of the wider forestscarbon policy nexus

    The Use of Quasigeoid in Leveling Through Terrain Obstacles

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    In these paper are presented two ways of performing leveling through terrain obstacles. They use properties of the quasigeoid course with respect to the ellipsoid within a given area. The analysis of changes in quasigeoid to ellipsoid slope have been made on the basis of the national quasigeoid models, calculating the slope components ξ, η. This allows to present practical recommendations for location of intermediate benchmarks in the leveling methods through obstacles

    Oddziaływanie stawów detencyjnych na wielkość ładunku rumowiska unoszonego – przegląd wyników badań

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    W pracy przedstawiono przegląd wyników badań dotyczących wpływu stawów detencyjnych (tj. zbiorników o niewielkiej pojemności, lokalizowanych w terenach zurbanizowanych, spowalniających odpływ wód wezbraniowych) na redukcję ładunku rumowiska unoszonego. Wraz z unosinami w stawach zatrzymywane są znaczne ilości metali ciężkich, związków fosforu i innych zanieczyszczeń. Proces sedymentacji cząstek zachodzi efektywniej w przypadku zbiorników piętrzących wodę stale niż w przypadku zbiorników suchych. Do prawidłowego funkcjonowania obiektów niezbędna jest ich regularna kontrola. Narzędziem, które można wykorzystać do oceny zdolności stawów detencyjnych do zatrzymywania rumowiska unoszonego, jest przedstawiony w pracy model koncepcyjny. Traktuje się w nim zbiornik jak komorę z pełnym wymieszaniem. Model charakteryzuje się niską liczbą parametrów oraz prostą strukturą, co ułatwia jego zastosowanie w przypadku zlewni nieobserwowanych. Praca ma na celu zwrócenie uwagi na problematykę jakości odpływu w zlewniach miejskich oraz na rolę, jaką stawy detencyjne mogą odgrywać w procesie podczyszczania wody
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