Tab. 6.5: Sampling in the Vipava springs during the forth tracing experiment in 1995. SAMPLING POINT DATE SAMPLING METHOD 4/2, 4/5, 4/7 25.10.95 - 21.12.95 4x per day 4/2, 4/5, 4/7 22.12.95 - 01.03.96 3x per day 4/2, 4/5, 4/7 02.03.96 - 02.06.96 Ix per day 4/5 28.10.95 - 30.10.95 automatic sampler out of function 4/2, 4/7 29.10.95 - 03.11.95 automatic sampler out of function 4/5, 4/7 06.12.95 -11.12.95 automatic sampler out of function 6.2. DESCRIPTION OF THE HYDROLOGICAL SITUATIONS DURING THE TRACING EXPERIMENTS (N. TRIŠIČ & J. POLAJNAR) 6.2.1. The Hubelj Spring in the Time of the First Tracing Experiment (October 14 to December 31, 1993) The values of discharges of the Hubelj were above average in the time of tracing experiment, if compared to the average over many years for the same period (October, November, December 1961-90). The mean discharge was by one third higher in the time of the tracing experiment than the mean discharge of the period. The highest discharge in the time of tracing experiment was higher by 2-times than the mean of extremes of the maximum high discharges in the period, and the lowest discharge was equal to the mean of extremes of the minimum low discharges in the period. At the injection of the tracer on October 14, 1993, the initial discharge of 2.786 mVsec was only one half of the average mean discharge in the time of tracing experiment. On October 22, the high water wave followed with the highest discharge of 29.13 mVsec, which is more than the mean of extremes of the maximum high discharges in the period. By the end of October, the discharge of the Hubelj decreased below the value of discharge at the time of injection of the tracer, and on November 9, the second minor high water wave occurred with the highest discharge which was lower than the mean of extremes of the maximum high discharges in the period. The discharge kept decreasing by December 6, when the lowest value was registered in the time of tracing experiment and was equal to the mean of extremes of the minimum low discharges in the period. In mid-December, the last high water wave occurred, with the highest discharge of 34.59 mVsec, which is almost by 2-times higher than the mean of extremes of the maximum high discharges in the period. The discharge of the Hubelj decreased by the end of December and was approx. equal to the discharge at the time of injection of the tracer (Fig. 6.2). 35 30 25 THE HUBELJ HOURLY DISCHARGES 1993 O y-r-y- >NNNNNNN aicotDoicocdoico (NOOO'-'r-^CM Fig. 6.2: Comparison of the Hubelj discharge behaviour during the second tracing experiment in April 1994 with the characteristic discharges (gauging profile Hubelj -Ajdovščina). Measured Hubelj discharge at the time of injection in Belo Brezno (October 14, 1993, 13:00) was Q.= 2.786 mVs. The following discharge data (Q in mVs) was evaluated: Oct 14 to Dec 31, 1993 Oct 14 to Nov 13, 1993 long-time (1961-1990) Q 1993 ^mean Q Q ^mean Q ^max 1.085 5.73 34.59 2.11 6.77 2914 0.382 3.03 5950 Oct Nov Dec average 10.1 7.64 5.11 7.6 3.58 4.19 3.51 3.76 6.2.2. The Hubelj Spring in the Time of the Second Tracing Experiment (April 16 to July 31, 1994) The values of discharges of the Hubelj were below average in the time of tracing experiment, if compared to the average over many years for the same period (April, May, June, July 1961-90). The mean discharge amounted to 2.08 mVsec in the time of tracing experiment and was by one third lower than the mean discharge of the period. The lowest discharge of 0.29 mVsec was only one quarter of the mean of extremes of the minimum low discharges in the period, and the highest discharge of 31.27 mVsec exceeded by 2-times and a half the mean of extremes of the maximum high discharges in the period. At the injection of the tracer on April 16, 1994, the initial discharge of 5.409 mVsec was higher than the mean discharge of the period and it was higher by 5-times than the mean discharge in the time of tracing experiment. THE HUBELJ HOURLY DISCHARGES 1994 lltllf I 2 S 2 S E;; -