Wyniki wyszukiwania - BazTech

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Współczesny morfosystem strefy młodoglacjalnej

Kostrzewski A., Zwoliński Z., Andrzejewski L., Florek W., Mazurek M., Niewiarowski W., Podgórski Z., Rachlewicz G., Smolska E., Stach A., Szmańda J., Szpikowski J.

Landform Analysis

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2008

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Vol. 7

7--11

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Metodyka estymacji stężeń roztworów w odpływie rzecznym

Stach A.

Przegląd Naukowy Inżynieria i Kształtowanie Środowiska

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2002

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Vol. 11, No. 2

112--129

EN

The main aim of the present study is to compare a wide set of methods for estimation solute concentrations in river outflow, both statistical parameters of population and instant values. The reference data set consist two years of daily measurements from two catchments: lowland and mountainous. Each data set was modified to simulate seven series of measurements with weekly intervals. This allows to compare both accuracy and in some extent also precision of each tested estimation methods. No one method are always better than others. It depends not only on parameter under consideration but also on particular data subset. Generally the worse choice in terms of both accuracy and precision is to use rating relationships with discharge. Surprisingly very good result was obtained using simple linear interpolation. For routine calculation of river solute concentration from infrequent data, cubic spline was recommended both by it’s good performance, simplicity and popularity in relatively chip mathem atical-statistical software for PC. The best method in comparison was collocated ordinary cokriging (cOCK). It’s performance is similar good both were secondary variable was discharge or specific electric conductivity of water (SEC). It is suggested that cOCK will be particularly useful for generating synthetic river solute concentration data for comparison of different methods for solute loads calculation (eg. Webb et al. 2000).

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Geostatystyczna identyfikacja mechanizmów transportu roztworów w ciekach

Stach A.

Przegląd Naukowy Inżynieria i Kształtowanie Środowiska

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2002

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Vol. 11, No. 2

130--143

EN

The geostatistical structural analysis was used to detect hidden mechanisms of solute transport in two contrasting temperate catchments: low land lakeland one and m ountainous. The data set consist two years of daily measurements of the discharge and two solute components for each catchment. In both catchment dissimilarity structure of analysed data in terms of semivariogram , is much the same: small nugget variance and two spherical components with the range 56 or 68 days first and 34-36 or 25-27 day second for mountainous and low land catchments respectively. With daily sampling interval the water in both river can be treated as mixture of three components, presumably surface, subsurface and ground outflow. Weak relationships between solute concentrations and discharge is mainly result of the share of first time component (quick runoff). Codispersion coefficients rise rapidly up to six days lag between discharge and solute concentration, and reaches its maximum between 15 and 30 days. For the quick runoff component relationship between solute concentration and discharge is positive, probably as an effect of periodic flushing effect of surface and subsuiface runoff (Klein 1981, Stach 2002). Factorial kriging can be used for separation time components both for river hydrogram and chemogram.