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This study describes the hydrological conditions of migration of potential pollutants to shallow groundwater in the Mogilnica River catchment, classified as a typically agricultural lowland catchment in Poland. The assessment of vulnerability of aquifers to the inflow of pollutants from the ground's surface was conducted with the use of the GOD rank method introduced by Foster, and the method of calculation of contamination migration time through the aeration zone according to the formula of Bachmat and Collin. Using the data collected in the geographic information system, digital (screen system) maps were prepared for the catchment, illustrating the spatial distribution of the analyzed parameters. There were identified zones with different degrees of groundwater resistance, including areas that, owing to hydrological conditions, are the most vulnerable to the inflow of pollution. The collected data sets were compared with information on the method of development and use of the catchment, which was the basis for classification of the scale of hazard for groundwater from existing and potential anthropogenic activity.
The study presents the results obtained following the analysis of the so-called Granger causality between daily and monthly temperatures of air and water for the period 1987–2013 carried out for the Noteć river and its two main tributaries: Drawa and Gwda. Granger causality relates to a situation where the data concerning past values of one time series provide important information helping to predict values of another series not included in the information about its past values. The analysis was based on the Granger causality test (of the first order). A causality relationship was established for daily temperature series both for the air-water and water-air directions of influence, which means that forecasting the pattern of river water temperatures from changes to air temperatures can yield better results when done based on data from the previous day. The model forecasting daily water temperature in the Noteć river on the basis of water and air temperatures from the previous day explained 0.07–0.27% of unique variance more than the model that used only water temperature from the previous day. The model forecasting the daily air temperature based on air and water temperatures from the previous day explained 0.3–0.79% of the variance more than the model, which uses only the air temperature from the previous day. For monthly series of water and air temperatures, different configurations of correlations in terms of Granger causality were established: one-way in water-air direction or no correlation, which may result from the river water thermal regime being disturbed by the local impact of anthropogenic factors. In addition, the analysed effect of Granger causality between series of random fluctuations of both temperature models confirmed that causal dependencies occur in both directions. The identification of causal relationships in terms of Granger causality confirms the influence of one data series on the evolution on another data series, and it defines the application potential of study results for the purpose of forecasting the changeability of thermal parameters of river waters. The obtained results may help improve the quality of forecasting changes in water thermal conditions, which is important for managing their environmental condition properly.
An assessment of ecological conditions of streams and other water bodies is one of the requirements of the Water Framework Directive No. 2000/60/EC. The paper deals with the potential use of hydrographic and sozological databases and thematic maps at a scale of 1:50,000 (Hydrographic Map, Sozological Map) compiled on their basis at selected stages of eco-hydrological evaluation of streams, especially at the stage of collecting information on water bodies. Attention was paid to the possible use of that data in identification of sections of river valley estimated from the point of view of its components, i.e. under protection, and determining the level of urbanization of the valley, location of municipal investments, infrastructure and hydraulic structures, which are the measures of the man-made transformation of the valley. An assessment of the ecological state and potential of surface waters is the basis of eco-hydrological studies and the fundamental requirement of the Water Framework Directive, thus is the starting-point for river system valorisation.
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