Table 3.
Overview of the different monitoring strategies and the resulting (1) probability to detect precipitation-induced TCC events and (2) accuracy of peak concentration estimations of bacteria in karstic spring water during a 3-month observation period (Figure 2, Spring B).
| Monitoring strategy | Probability of TCC event detection | Estimation of TCC peak concentration (R = sampled maximum divided by true maximum) | ||||||
|---|---|---|---|---|---|---|---|---|
| n | Average | Range (%) | Median (%)a | 25% Quartile (%)a | 75% Quartile (%)a | Median range (%)b | ||
| Constant interval | Quarterly | 1 | 10 | 3–16 | 43 (31) | 19 (17) | 61 (59) | 14–84 |
| Monthly | 3 | 29 | 10–48 | 44 (31) | 19 (17) | 62 (59) | 14–84 | |
| Weekly | 14 | 86 | 42–100 | 54 (47) | 34 (29) | 67 (68) | 33–84 | |
| Bi-weekly | 28 | 99 | 85–100 | 64 (64) | 52 (49) | 80 (84) | 38–86 | |
| Daily | 99 | 100 | – | 87 (89) | 72 (82) | 93 (93) | 56–94 | |
| Randomly (working hours) | Quarterly | 1 | 9 | 2–15 | 41 (32) | 20 (17) | 62 (60) | 16–83 |
| Monthly | 3 | 24 | 9–37 | 43 (36) | 21 (18) | 63 (64) | 16–83 | |
| Weekly | 14 | 71 | 35–91 | 51 (50) | 32 (26) | 68 (74) | 23–85 | |
| Bi-weekly | 28 | 91 | 63–100 | 61 (62) | 41 (38) | 84 (86) | 38–87 | |
| Daily | 70 | 100 | – | 81 (87) | 55 (58) | 92 (92) | 46–93 | |
| Targeted | 33 | 100 | – | 89 (90) | 69 (72) | 92 (92) | 46–94 | |
For the constant sampling interval and random sampling, multiple possible realizations were statistically summarized whereas for the targeted sampling only one realization exists in this study. See Figure 3, Figures S2, S3 for graphical representations of the results and Table S1 for results of individual TCC events.
For the combination of all realizations for all 11 TCC events in Figure 3 (in brackets without events 7 and 8).
For the 11 individual TCC events; see Table S1 for all values.