A set of corpora for 120 languages automatically collected from wikipedia and the web.
Collected using the W2C toolset: http://hdl.handle.net/11858/00-097C-0000-0022-60D6-1
The paper evaluates changes in the water temperature of the Vistula River – one of the longest rivers in Europe. Mean monthly and annual water temperatures from the period 1971–2017 for 11 stations along the entire length of the river revealed the increasing trends. The mean increase in water temperature in the analysed multi-annual period was 0.31 °C dec–1. In the majority of analysed stations, the key factor determining changes in the water temperature of the river was air temperature. The observed water warming in the Vistula River should be considered an exceptionally unfavourable situation in the context of importance of water temperature for a number of processes and phenomena occurring in river ecosystems. Given the scale of changes, fast measures should be undertaken to slow down the warming.
Water flow in a single fracture with variable aperture was studied by means of numerical modeling. For this purpose, two numerical models were developed. Computer simulations of water flow rates, fracture contact areas and transmissivities for fractal and nonfractal fractures were performed. Water flow rates were approximated by a trend function. The effect of the grid size upon the stability of results as well as the dependence of the fracture transmissivity on rate of contact area were studied. The achieved results were compared with measured data. and Studie se věnuje proudění podzemní vody v samostatné puklině metodou numerického modelování. K tomu účelu jsme vyvinuli dva numerické modely. Byly provedeny série numerických simulací proudění vody a výpočtu kontaktní plochy a transmisivity pukliny pro obecný typ pukliny. Byly studovány vliv velikosti sítě generované pukliny na stabilitu perkolačních charakteristik a závislost propustnosti pukliny na poměrné velikosti kontaktní plochy. Získané výsledky byly vyhodnocovány ve vztahu ke známým experimentálním datům.
Artificial basins are used to recharge groundwater and protect water pumping fields. In these basins, infiltration
rates are monitored to detect any decrease in water infiltration in relation with clogging. However, miss-estimations
of infiltration rate may result from neglecting the effects of water temperature change and air-entrapment. This study
aims to investigate the effect of temperature and air entrapment on water infiltration at the basin scale by conducting successive
infiltration cycles in an experimental basin of 11869 m2 in a pumping field at Crepieux-Charmy (Lyon, France).
A first experiment, conducted in summer 2011, showed a strong increase in infiltration rate; which was linked to a potential
increase in ground water temperature or a potential dissolution of air entrapped at the beginning of the infiltration. A
second experiment was conducted in summer, to inject cold water instead of warm water, and also revealed an increase
in infiltration rate. This increase was linked to air dissolution in the soil. A final experiment was conducted in spring with
no temperature contrast and no entrapped air (soil initially water-saturated), revealing a constant infiltration rate. Modeling
and analysis of experiments revealed that air entrapment and cold water temperature in the soil could substantially
reduce infiltration rate over the first infiltration cycles, with respective effects of similar magnitude. Clearly, both water
temperature change and air entrapment must be considered for an accurate assessment of the infiltration rate in basins.