Effect of wave-induced mixing on Antarctic sea ice in a high-resolution ocean model     

Thomas  Steven  Babanin  Alexander V.  Walsh  Kevin J. E.  Stoney  Lachlan  Heil  Petra 《Ocean Dynamics》2019,69(6):737-746

Ocean Dynamics - In this study, we investigate how sea ice extent and thickness are affected by additional turbulent mixing from unbroken surface waves. This ‘surface wave mixing’ (SWM)...  相似文献   

Establishing irrigation potential of a hillside aquifer in the African highlands     

Seifu A. Tilahun  Debebe L. Yilak  Petra Schmitter  Fasikaw A. Zimale  Simon Langan  Jennie Barron  Jean-Yves Parlange  Tammo S. Steenhuis 《水文研究》2020,34(8):1741-1753

Feeding 9 billion people in 2050 will require sustainable development of all water resources, both surface and subsurface. Yet, little is known about the irrigation potential of hillside shallow aquifers in many highland settings in sub-Saharan Africa that are being considered for providing irrigation water during the dry monsoon phase for smallholder farmers. Information on the shallow groundwater being available in space and time on sloping lands might aid in increasing food production in the dry monsoon phase. Therefore, the research objective of this work is to estimate potential groundwater storage as a potential source of irrigation water for hillside aquifers where lateral subsurface flow is dominant. The research was carried out in the Robit Bata experimental watershed in the Lake Tana basin which is typical of many undulating watersheds in the Ethiopian highlands. Farmers have excavated more than 300 hand dug wells for irrigation. We used 42 of these wells to monitor water table fluctuation from April 16, 2014 to December 2015. Precipitation and runoff data were recorded for the same period. The temporal groundwater storage was estimated using two methods: one based on the water balance with rainfall as input and baseflow and evaporative losses leaving the watershed as outputs; the second based on the observed rise and fall of water levels in wells. We found that maximum groundwater storage was at the end of the rain phase in September after which it decreased linearly until the middle of December due to short groundwater retention times. In the remaining part of the dry season period, only wells located close to faults contained water. Thus, without additional water sources, sloping lands can only be used for significant irrigation inputs during the first 3 months out of the 8 months long dry season.  相似文献   

European glacial relict snails and plants: environmental context of their modern refugial occurrence in southern Siberia          下载免费PDF全文

Michal Horsák  Milan Chytrý  Petra Hájková  Michal Hájek  Jiří Danihelka  Veronika Horsáková  Nikolai Ermakov  Dmitry A. German  Martin Kočí  Pavel Lustyk  Jeffrey C. Nekola  Zdenka Preislerová  Milan Valachovič 《Boreas: An International Journal of Quaternary Research》2015,44(4):638-657

Knowledge of present‐day communities and ecosystems resembling those reconstructed from the fossil record can help improve our understanding of historical distribution patterns and species composition of past communities. Here, we use a unique data set of 570 plots explored for vascular plant and 315 for land‐snail assemblages located along a 650‐km‐long transect running across a steep climatic gradient in the Russian Altai Mountains and their foothills in southern Siberia. We analysed climatic and habitat requirements of modern populations for eight land‐snail and 16 vascular plant species that are considered characteristic of the full‐glacial environment of central Europe based on (i) fossil evidence from loess deposits (snails) or (ii) refugial patterns of their modern distributions (plants). The analysis yielded consistent predictions of the full‐glacial central European climate derived from both snail and plant populations. We found that the distribution of these 24 species was limited to the areas with mean annual temperature varying from ?6.7 to 3.4 °C (median ?2.5 °C) and with total annual precipitation varying from 137 to 593 mm (median 283 mm). In both groups there were species limited to areas with colder and drier macroclimates (e.g. snails Columella columella and Pupilla loessica, and plants Kobresia myosuroides and Krascheninnikovia ceratoides), whereas other species preferred areas with relatively warmer and/or moister macroclimates (e.g. snails Pupilla turcmenica and P. alpicola, and plants Artemisia laciniata and Carex capillaris). Analysis of climatic conditions also indicated that distributional shifts of the studied species during the Pleistocene/Holocene transition were closely related to their climatic tolerances. Our results suggest that the habitat requirements of southern Siberian populations can provide realistic insights into the reconstruction of Eurasian, especially central European, glacial environments. Data obtained from modern populations also highlight the importance of wet habitats as refugia in the generally dry full‐glacial landscape.  相似文献   

The Nysa-Morava Zone: an active tectonic domain with Late Cenozoic sedimentary grabens in the Western Carpathians’ foreland (NE Bohemian Massif)     

Petr Špaček  Ondřej Bábek  Petra Štěpančíková  Jan Švancara  Jana Pazdírková  Jan Sedláček 《International Journal of Earth Sciences》2015,104(4):963-990

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The application of electrical resistivity tomography and gravimetric survey as useful tools in an active tectonics study of the Sudetic Marginal Fault (Bohemian Massif, central Europe)     

Petra &#x;tpan íkov  Ji&#x;í Dohnal  Tom&#x; Pnek  Monika &#x;j  Veronika Smolkov  Karel &#x;ilhn 《Journal of Applied Geophysics》2011,74(1):69-80

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Impact of the deeper geological basement on soil gas and indoor radon concentrations in areas of Quaternary fluvial sediments (Bohemian Massif,Czech Republic)     

Ivan Barnet  Petra Pacherová 《Environmental Earth Sciences》2011,63(3):551-557

The relationship of soil gas radon Rn²²² and indoor radon was studied within the Quaternary fluvial sediments of the Czech Republic. The processing of data selection from the radon database of the Czech Geological Survey and indoor radon data (database of the National Radiation Protection institute) has proved the concentration dependence of radon in Quaternary fluvial sediments on deeper bedrock. The ArcGIS processing was accompanied by the field verification in five profiles, intersecting the granitoid Central Bohemian Plutonic Complex and its rim rock types. Both theoretical and experimental results show dependence of soil gas radon and indoor radon concentrations in Quaternary fluvial sediments on deeper geological basement, thus leading to the conclusion that the lateral transport of Quaternary sediments does not play such a dominant role in radon concentrations, as was thought previously. This fact will enable to determine precisely the radon index of Quaternary sediments (in the Czech radon mapping classified as an intermediate index) into three categories according to the lithology of their geological basement.  相似文献   

Traffic-related immissions and their impact on historic buildings: implications from a pilot study at two German cities   总被引：1，自引：1，他引：0  

Michael Auras  Silvia Beer  Petra Bundschuh  Joachim Eichhorn  Martin Mach  Dirk Scheuvens  Michael Schorling  Jonas von Schumann  Rolf Snethlage  Stephan Weinbruch 《Environmental Earth Sciences》2013,69(4):1135-1147

Besides the enormous improvement of air quality in Germany due to the reduction of sulphur dioxide emissions in the last decades, high immissions of nitrogen oxides and fine particulate matter are frequently observed at traffic-rich urban sites. The changed chemical composition of air pollution requires a new investigation of its impact on historic buildings constructed of natural stone. In a pilot study a multi-disciplinary approach was chosen to obtain information on the actual pollution situation of historic buildings and monuments at traffic hotspots in Germany. The study concentrated on the two German cities of Munich and Mainz of different size, traffic volume and stone inventory. Dose–response functions were calculated to demonstrate the change of impact of different pollutants over the last three decades, and for comparison of traffic hotspots and housing areas of both cities. Numeric modelling on a city-scale was used to identify the historic buildings and monuments affected by elevated traffic immissions. Because a relevant part of these pollutants is dominated by short-range transport, the differences of wind speed and deposition rates were calculated using a street-scale 3D flow and dispersion model regarding traffic volume, wind regime and adjacent buildings. Finally, particulate matter was sampled at different positions of two buildings heavily exposed to traffic emissions. Individual particles were investigated by environmental scanning electron microscopy. After classification of the particles into different chemical groups, the fraction of traffic-induced particulate matter was quantified. Summarizing the results, it must be stated that soiling by traffic-related particulate matter, deposition of nitrates deriving from exhaust emission and other diffusely emitted components bear a severe damage potential for natural building stone at least locally at traffic-rich urban sites.  相似文献   

An evaluation of trace metal distribution and environmental risk in sediments from the Lake Kalimanci (FYR Macedonia)     

Petra Vrhovnik  Nastja Rogan Šmuc  Tadej Dolenec  Todor Serafimovski  Matej Dolenec 《Environmental Earth Sciences》2013,70(2):761-775

Pollution from mining activities is a significant problem in several parts of the Republic of Macedonia. A geochemical study of the surficial sediments of Lake Kalimanci in the eastern part of the Republic of Macedonia was carried out to determine their elemental compositions and to evaluate the pollution status of lake sediments by employing an enrichment factor (EF). The major and trace element contamination in surficial lake sediments was studied to assess the effects of metalliferous mining activities. The mean concentrations of major elements (wt%) Si 23.5, Al 7.9, Fe 6.6, Mg 1.3, Ca 3.8, Na 1.1, K 2.3, Ti 0.4, P 0.2, Mn 0.6 and trace elements ranged within Mo 1.0–4.6 mg kg^?1, Cu 144.4–1,162 mg kg^?1, Pb 1,874–16,300 mg kg^?1, Zn 2,944–20,900 mg kg^?1, Ni 21.7–79.3 mg kg^?1, Cd 16.5–136 mg kg^?1, Sb 0.6–3.6 mg kg^?1, Bi 3.0–24,3 mg kg^?1 and Ag 1.4–17.3 mg kg^?1. The EF ranged within 0.12–590.3. Among which, Cd, Pb, Zn and As have extremely severe enrichment. The data indicate that trace elements had extremely high concentrations in Lake Kalimanci surficial sediments owing to the anthropogenic addition of contaminants.  相似文献   

Erratum to: Magmato-sedimentary Carboniferous to Jurassic evolution of the western Tauern window,Eastern Alps (constraints from U-Pb zircon dating and geochemistry)     

Petra Veselá  Frank Söllner  Friedrich Finger  Axel Gerdes 《International Journal of Earth Sciences》2012,101(2):603-603

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Population and distribution changes of two coexisting river amphipods after the closure of a new large dam     

Krešimir Žganec  Petra Đurić  Sandra Hudina  Sanja Gottstein 《Limnologica》2013,43(6):460-468

This study examined short-term changes of population size and distribution of two coexisting river amphipods after a major disturbance event – the closure of a new large dam on the Goja?ka Dobra River (Central Croatia) in June 2010. In the pre-disturbance period, coexistence of the two species, the endemic moss specialist Echinogammarus cari and the widespread microhabitat generalist Gammarus fossarum, was promoted by differential microdistribution between two dominating types of microhabitats, moss and stony substrate. E. cari was dominant in mosses and G. fossarum on stony substrate, representing an excellent case of spatial niche partitioning between two species of river amphipods. Drastic change in water quality and increased load of suspended particles that accumulated in mosses soon after the dam closure were the main factors that contributed to E. cari rapid population decline at sites downstream of the new dam. G. fossarum was much less affected by such changes, exhibiting no drastic population decline and even an increase in population size after disturbance event at three examined sites. Hence, specialization of E. cari for moss microhabitats which enabled stable coexistence of the two species before damming made it more vulnerable to disturbance and resulted in dominance shift in moss microhabitats in favour of G. fossarum after dam closure. This shift might reduce the probability of E. cari population recovery downstream from the new dam and change its current conservation status from endangered to critically endangered if it completely disappears downstream of the dam. Urgent measures aimed at conservation of this endemic species are proposed and discussed.  相似文献