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51.
The present paper introduces the topical area of the Polish-Swiss research project FLORIST (Flood risk on the northern foothills of the Tatra Mountains), informs on its objectives, and reports on initial results. The Tatra Mountains are the area of the highest precipitation in Poland and largely contribute to flood generation. The project is focused around four competence clusters: observation-based climatology, model-based climate change projections and impact assessment, dendrogeomorphology, and impact of large wood debris on fluvial processes. The knowledge generated in the FLORIST project is likely to have impact on understanding and interpretation of flood risk on the northern foothills of the Tatra Mountains, in the past, present, and future. It can help solving important practical problems related to flood risk reduction strategies and flood preparedness.  相似文献   
52.
The combination of magnetic and geochemical methods was used to determine the mineralogy, grain size and domain structure of magnetic particles in indoor dust collected in 195 sites in Warsaw, Poland. Data show an asymmetric distribution of magnetic susceptibility (χ) in the wide range of 20–1514 × 10?8 m3 kg?1. Comparison of magnetic parameters shows that the internal dust contains outside pollution characteristic for air and soil. More than 90% of indoor dust samples were characterized by roughly uniform magnetic mineralogy, typical for fine grained magnetite (diameter of 0.2–5 μm), and grain size between pseudo-single-domain and small multi-domain with small contribution of superpara-magnetic particles (~10%). Samples with χ larger than 220 × 10?8 m3 kg?1 contain mainly magnetite and an anthropogenic metallic Fe with T C > 700°C. The indoor dust contains, characteristic for the urban areas, spherical magnetic particles originated from fossil fuel combustion processes and mixture of irregular angular iron-oxides grains containing other elements, including Na, Ca, Al, Si, K, S, Mn, Cl, and Mg.  相似文献   
53.
The study of seasonal dynamics of net phytoplankton was carried out above and below the hydroelectric plant (HP) on the Pas ka River. Correlations were found between the abundance of diatoms and conductivity, O2, PO4; the abundance of cyanobacteria and water temperature and conductivity, and the abundance of chlorophytes and O2 and Ntot. Multiple correlations revealed the most significant factor for diatom development is PO4, for cyanobacteria is water temperature, and for chlorophytes is Ntot. A lower abundance and biomass of phytoplankton, and less species diversity and nutrient concentrations were registered below the HP than above it. The seasonal dynamics of phytoplankton abundance provided similar results. The maximum biomass of the assemblage was found earlier below the HP, in April, than above it, in May. However, no differences were recorded in the dominant species within phytoplankton abundance. The phytoplankton biomass was dominated by the Melosira varians and Spirogyra sp., which are typical taxa of plant periphyton and possibly emanate from the concrete elements of the dam. This HP changed the local hydrological and environmental conditions, affecting available nutrients, and thereby phytoplankton development in the vegetative season.  相似文献   
54.
The Post-Forum Study Tour following the 4th World Landslide Forum 2017 in Ljubljana (Slovenia) focuses on the variety of landslide forms in Slovenia and its immediate NW surroundings, and the best-known examples of devastating landslides induced by rainfall or earthquakes. They differ in complexity of the both surrounding area and of the particular geological, structural and geotechnical features. Many of the landslides of the Study Tour are characterized by huge volumes and high velocity at the time of activation or development in the debris flow. In addition, to the damage to buildings, the lives of hundreds of people are also endangered; human casualties occur. On the first day, we will observe complex Pleistocene to recent landslides related to the Mesozoic carbonates thrust over folded and tectonically fractured Tertiary siliciclastic flysch in the Vipava Valley (SW Slovenia), serving as the main passage between the Friulian lowland and central Slovenia, and thus also an important corridor connecting Northern Italy to Central Europe. A combination of unfavourable geological conditions and intense short or prolonged rainfall periods leads to the formation of different types of complex landslides, from large-scale deep-seated rotational and translational slides to shallow landslides, slumps and sediment gravity flows in the form of debris or mudflows. The second day of the study tour will be held in the So?a River Valley located in NW Slovenia close to the border with Italy, where the most catastrophic Sto?e landslide in Slovenia recently caused the deaths of seven people, and the nearby Strug landslide, which is a combination of rockfall, landslide and debris flow. The final day of the Post-Forum Study Tour will start in the Valcanale Valley located across the border between Slovenia and Italy, severely affected by a debris flow in August 2003. The flow caused the deaths of two people, damaged 260 buildings; large amounts of deposits blocked the A23 Highway, covering both lanes. In Carinthia (Austria), about 25 km west of Villach, the Dobra?/Dobratsch multiple scarps of prehistoric and historic rockslides will be observed. Dobratsch is a massive mountain ridge with a length of 17 km and a width of 6 km, characterized by steep rocky walls. The 3-day study tour will conclude with a presentation of the Poto?ka planina landslide, a slide whose lower part may eventually generate a debris flow and therefore represents a hazard for the inhabitants and for the infrastructure within or near the village of Koro?ka Bela.  相似文献   
55.
According to historical sources, the development of settlement around Lake Goci& aogon; during the last 330 yrs was intense at two time periods: the second half of the 1700's, and from ca. 1880 until 1944. The small farms were then abandoned, following which the lake surroundings were planted with forest trees. The presented study of human influence on the lake ecosystem and surrounding vegetation has been based on analyses of general sediment composition and its chemistry, pollen, Cyanobacteria, Chlorophyceae, Rotatoria, Cladocera, and a preliminary diatom survey. The history of human impact has been divided into four phases: 1. Phase of small local hamlets (before ca. 1770): The human impact was rather moderate then, but the cultivation of Canabis sativa, Secale cereale and later of Fagopyrum is evidenced from that time. 2. Phase of Hollandii settlement (ca. 1770-1863). Its influence is indicated first by the recession of deciduous wood (Corylus, Carpinus) stands, which triggered drastic drop of calcium in sediments. The development of rural economy in the area, including, an extension of agriculture (Secale and other cereals, crucifers, potatoes), and animal breeding based partly on grazing in the forest, is evidenced only after 1820. 3. Phase of German colonization (1863-1944): In the early periods (before 1910) the pollen spectra do not document any essential change in the type of farming, however, a serious disturbance of the lake ecosystem and sediment chemistry is evidenced by the blooms of Araphidinae diatoms and Tetraedron minimum, a maximum frequency of Bosmina longirostris, disturbances of the regular spring blooms of Chrysophyceae, appearance of vivianite, distinct maxima of organic matter, potassium, and iron concentration in sediments and an increase of the sedimentation rate. An intensification of agricultural activities commenced around 1910; woods, including also pinewoods, were then heavily devastated, and farming extended on poor soils, what was symptomatic for the general poverty of population. Coincidently in the lake, Centriceae showed blooms, Araphidinae diatoms and Tetraedron minimum developed, and the content of potassium, iron and phosphorus increased substantially, indicating altogether rising eutrophication. 4. Phase of restoration of the natural landscape (after 1945): The farm degradation from ca. 1944 is very weakly expressed in pollen data, which show a substantial fall of farming indicators from 1953/6 only, when the whole area was used for forest plantation. It was accompanied by a certainly spontaneous development of Betula and Alnus woods, this process progressing till recent time. The gradual extinction of farming activity near Lake Goci was accompanied by abrupt changes in the lake ecosystem, expressed by the restored blooms of Chrysophyceae expansion of planktonic Cladocera, rapid decline of phosphorus and extinction of vivianite from sediments. As documented by the drop of Cu/Zn ratio, lake hypolimnion has been weakly oxidized since 1949, what was probably responsible for the drop of Fe and Mn content in sediments. Increasing strength of overturns affected preservation of laminae in sediments, which almost completely disappeared after 1966.  相似文献   
56.
Thirteen polycyclic aromatic hydrocarbons (PAH) compounds have been identified in spa waters of 10 different health sources in the Sudetes region. In some of the waters the amount of PAH exceed the standard limits set up by the World Health Organization (WHO). The results obtained show that PAH can be a sensitive indicator of pollution of underground water.  相似文献   
57.
The sediment trap technique was used to study the sedimentation processes in two parts of Lake Goci, central Poland, the deep of the main basin and the shallow bay area. From field and lab data was noted that seasonal and annual deposition of pollen grains on the lake bottom was disturbed in the main basin by an increase in water mass dynamics and by resuspension and focusing. Greater concordance between pollen sedimentation and the flowering periods of plants was found in the bay area, where sediment resuspension took place sporadically and with less intensity, compared to the main basin. Futhermore, it is suggested that resuspension of pollen can occur even if laminated sediments are formed, a process which therby diminishes the chronostratigraphic value of sediments and pollen analyses.  相似文献   
58.
Water Resources - The aim of the study was to show which morphometric traits of lakes influence the development of the rush zone of lakes and how buffer zone management influences analyzed features...  相似文献   
59.
The role of single-domain (SD) magnetic particles in creation of inverse magnetic fabrics is investigated on simple mathematical models using a realistic estimate for SD intrinsic susceptibility. In contrast to the fraction created by multi-domain (MD) particles, in which the anisotropy of magnetic susceptibility (AMS) is controlled by both the grain AMS and intensity of the preferred orientation of the particles, the AMS of the SD fraction is controlled solely by the intensity of the preferred orientation. The degree of AMS of ensemble of SD grains with a preferred orientation is therefore much higher than that of the same ensemble of MD particles implying the existence of frequent inverse magnetic fabrics. However, the occurrence of inverse magnetic fabrics due to SD particles is more the exception than the rule. Consequently, the amounts of SD particles is probably in general low. Nevertheless, the presence of SD particles in amounts insufficient to create inverse magnetic fabrics may diminish the whole rock AMS substantially. This can be one of the reasons for relatively low AMS in volcanic rocks whose magnetic particles may be really small obeying the conditions for the existence of SD particles.  相似文献   
60.
Formaldehyde levels were determined in various forms of atmospheric precipitation (rain, snow, road and roof runoff, throughfall) and deposition (rime, hoarfrost, dew) collected over twelve months at various locations in two large urban agglomerations and along two highways. HCHO was found in 303 of 500 samples analyzed, with concentrations ranging from 0.05 to 10.7 mg/dm3. The results confirmed the significant effect of vehicular traffic on formaldehyde levels in various forms of wet deposition. Correlations of formaldehyde levels with other parameters commonly monitored in precipitation and/or deposition were also examined. No correlation was found between HCHO levels and rain volume. On the other hand, positive correlations were found for hydrogen peroxide, non-sea-salt sulphate, nitrate, ammonia, and total organic carbon (TOC). In addition, the effect of selected meteorological parameters (temperature, wind speed, wind direction, rainfall) on the concentration of formaldehyde in various forms of precipitation and runoff (road runoff, roof runoff, throughfall) was studied. The only correlation found was that between HCHO concentration and daily rainfall.  相似文献   
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