Vízrajzi Évkönyv 97., 1992 (Budapest, 1993)
Tartalomjegyzék
such calculations the I0 and Q0 values pertaining to the particular stage have been obtained from the tabulation containing the corresponding values of the stages (h, cm), the surface slope under steady flow conditions (I0, cm/km) and the streamflow rate (Q0, m3/s) under similar conditions. Hereafter, in the knowledge of the simultaneous stage data on the auxiliary gage also indicated in the table, the actual surface slope (I, cm/km) for the given instant over the reach included by the two gages has been determined. These data have then been entered into the formula Q = Qo V(Mo) to find the actual streamflow rate Q(m3/s) passing the gaging cross section under consideration. For estimating the streamflow rates through the Szeged gaging cross section on the Tisza River, allowance had to be made, besides the stages on the Mindszent gage, also for the stages on the Makó gage on the Maros River. Consequently, the value of I0 had to be found from the auxiliary table in tenns of the stages at Szeged and at Makó. The streamflow rates through the cross sections, for which three-, or multi-variate relationships are published can be calculated only by taking the other two (or three) variables simultaneously into consideration (no variable must be omitted, or neglected in the calculations). Typical water temperature data are given for the gages which are representative for longer river sections controlling the variations in water temperature. The water temperatures are measured in the morning at 10 to 40 cm depth below the water surface. The hydrological particulars (stages, streamflow rates etc.) over some streams, or sections of streams, such as the Sió Canal, some sections in the Tisza River System, are influenced by human activites, such as the operation of weirs, diversions, discharges. The extend of these influences varies with time, and the length of the river section affected depends on stage. The duration in time and range of these effects can be indentified by a detailed analysis of the observation data alone. The data on sediment transport - both for the current year and the longer period - are values estimated from observation data. The values corresponding to the highest discharges on record and observed during the year of report and before the year of report have been entered as extreme values. The concentration of suspended sediment is estimated on the basis of samples taken from 7 to 9 verticals in a cross section. Sample of one litre volume are taken at ten points evenly spaced over each vertical. The mean concentration in the vertical is found from the ten samples combined. The extreme values have been calculated by extrapolating the correlations between the quantities describing sediment transport, and should therefore be regarded as approximate values only. 3. The chapter containing the data on subsurface waters has been completed with the water levels in the key deep wells (on artesian- and karstic waters), and with the hydrographs of some artesian-water observation wells. The elevations of the springs above the Baltic level have in some instances been obtained from maps, in others by geodetical surveying. The chapter of hydrometeorological data contains monthly and annual precipitation depths, the depth and water equivalent of the snow cover and the evaporation from open water surface. THE MAPS OF THE DATA COLLECTION NETWORK indicate the gages, springs, wells and meteorological stations of the standard network and the stations of the Central Meteorological Institute.-19-
