Vízügyi Közlemények, 1979 (61. évfolyam)

4. füzet - Kovács György: A korszerű vízrajzi munka alapelvei. II. rész: A vízfolyások észlelésével kapcsolatos adatképzés, valamint az adatfeldolgozás és tárolás

A korszerű vízrajzi munka 11. 557 a. The minimum number of sampling points within a particular cross-section, from which mean the concentration can be estimated with the required accuracy. b. The formulation of models from a large number of observation data by which it becomes possible to estimate the mass current of solids transported in suspended-, or dissolved form using other parameters accessible to continuous observation. The determination of the bed-load discharge presents special problems, there being no reliable method of measurement available thus far. — The description of water quality is a problem belonging primarily to the domain of biology, but the regular observation of these parameters has not been solved yet within the hydrographie network. First of all it would be required to specify the parameters of low number, but high information content, by which the results of biological tests could be entered into the data bank being organized. The data collected are unsuited to practical purposes unless they arc checked for accuracy and reliability. Besides numerical correctness the data must be checked for their contents, as well as physical meaning. One alternative method thereof consists of examining the temporal variations within a single observing station (setting a probability limit to the temporal variations, beyond which it is warranted to investigate individually th data for their reliability), the other involving the comparison of data observed simultaneously at adjacent stations (setting similarly the phsyically possible, or probable limits of deviations). The parameters which can be derived in several ways from different observation results, are checked for their substantial correctness by comparing the results obtained in different ways (e.g. actual évapotranspiration). — Manual data transfer is common source of errors (for instance on data carrier as input for computerized processing or data generation). In order to eliminate these, efforts should be made at performing such operations automatically. In the case of data observed directly these efforts are promoted by registering the signals from the recording transducers in digitalized form suited to computerized processing. Data generation by computer serves the same purpose. Another prerequisite of practical applicability is the accessibility of data. A solution must therefore be found for the conservation for documentation purposes of original, as well as improved and generated, data further for the storage of primary data sets in a way ensuring easy retrieval. The decision on which data groups are to be stored on computer data carriers is governed mainly by the frequency at which a type of data is used. In making water management decisions, in formulating long-range décisions and policies, in water resources analyses large volumes of hydrologie information must be used. It would be superfluous, however, to lay the foundations for such work in each particular case by a hydrologie study starting from the primary data. The data processing system should, therefore, incorporate organically the synthetizing acLivity, as a result of which the primary data are integrated over area and time, reducing thus the number of data to be stored, increasing their information content and simplifying accelerating, their retrieval. Finally, in connection with the group of problems related to the processing and storage of data, the publication thereof should also be eonsidercd. In the past accessibility of the data to a wide professional public was made possible mainly through the yearbooks published regulary. In modern times the function of meeting this demand must be assumed by data scries printed as computer output. The objective should be to present in yearbook form primarily the integrated information needed with high frequency, indicating clearly their interrelations and containing information on where and in what form can the detailed data be retrieved. * * *