210
E. Tomaszewski and K. Kubiak-Wójcicka
Table 11.1 Selected characteristics of low flows (1951–2015)
No. River
Gauging
cross-section
A
ALq LLq q 70 % q 95 % a
R 2
km 2
dm 3 s −1 km −2
–
–
1
Oder
Racibórz-Miedonia
6744.0 2.49 0.99 4.52 2.28
2
Oder
´
Scinawa
29583.8 2.24 0.79 3.85 2.06
3
Oder
Gozdowice
109729.1 2.26 1.13 3.27 2.04
4
Nysa
Kłodzka
Kłodzko
1084.0 3.20 0.87 5.82 3.07
5
Warta
Sieradz
8139.6 2.66 1.25 3.71 2.48 0.015 0.157
6
Note´ c
Pako´ s´ c
2356.2 0.75 0.22 1.20 0.52 0.005 0.065
7
Wieprza Stary Kraków
1518.7 6.10 3.69 8.10 6.20 0.025 0.194
8
Vistula
Nowy Bieru´ n
1747.7 3.11 0.86 5.49 3.02 0.028 0.229
9
Vistula
Sandomierz
31846.5 3.08 1.79 4.93 3.14 0.009 0.074
10
Vistula
Warszawa
84540.0 2.58 1.32 4.12 2.61 0.012 0.127
11
Vistula
Tczew
194376.0 2.16 1.03 3.50 2.21 0.007 0.074
12
Dunajec Nowy Targ
(Kowaniec)
681.1 5.04 2.35 9.93 5.24 0.023 0.077
13
San
Przemy´ sl
3686.5 2.83 0.54 6.05 2.85 0.030 0.420
14
Wieprz
Krasnystaw
3001.0 2.06 1.16 2.78 1.86 0.018 0.287
15
Pilica
Przedbórz
2535.9 2.28 1.01 3.75 2.17
16
Narew
Sura˙ z
3376.5 1.21 0.50 2.03 1.05 0.016 0.435
17
Drw˛ eca Elgiszewo
4959.4 2.88 1.16 4.03 2.62
A—catchment area, ALq—specific average minimum flow, LLq—specific lowest minimum flow,
q70%, q95%—specific low-flow threshold (percentile of the flow duration curve); parameters of
statistically significant (α = 0.05) linear trend of multiannual course of minimum flows: a—slope
coefficient, R 2 —determination coefficient
11.3 Minimum Flows
The minimum value of runoff is an integral part of a low flow regime. It indicates limitations during recession of flow on the dry weather curve and very often, the regime
of a basic groundwater aquifer drained by river channels during a drought. Minimum
value may also be modified by such factors as lakes, wetlands, or forest retention.
It may depend on some water management operations, especially downstream of
dammed lakes because of the guaranteed flow.
Distribution of annual flow minima is characterized by strong variation (Fig. 11.2).
The highest minimum specific flow exceeded 10 dm
3 s
−1 km
−2 in Dunajec river
whereas the lowest one reached two orders of magnitude less—0.2 dm
3 s
−1 km
−2 in
Note´ c river. A similar distribution of the Lq at the high average level is observed in
high mountainous and seaside catchments—Dunajec river—Nowy Targ and Wieprza
river—Stary Kraków which indicates that high annual precipitation determines low
flow regime much more than catchment size and its quantity of water resources.
E. Tomaszewski and K. Kubiak-Wójcicka
Table 11.1 Selected characteristics of low flows (1951–2015)
No. River
Gauging
cross-section
A
ALq LLq q 70 % q 95 % a
R 2
km 2
dm 3 s −1 km −2
–
–
1
Oder
Racibórz-Miedonia
6744.0 2.49 0.99 4.52 2.28
2
Oder
´
Scinawa
29583.8 2.24 0.79 3.85 2.06
3
Oder
Gozdowice
109729.1 2.26 1.13 3.27 2.04
4
Nysa
Kłodzka
Kłodzko
1084.0 3.20 0.87 5.82 3.07
5
Warta
Sieradz
8139.6 2.66 1.25 3.71 2.48 0.015 0.157
6
Note´ c
Pako´ s´ c
2356.2 0.75 0.22 1.20 0.52 0.005 0.065
7
Wieprza Stary Kraków
1518.7 6.10 3.69 8.10 6.20 0.025 0.194
8
Vistula
Nowy Bieru´ n
1747.7 3.11 0.86 5.49 3.02 0.028 0.229
9
Vistula
Sandomierz
31846.5 3.08 1.79 4.93 3.14 0.009 0.074
10
Vistula
Warszawa
84540.0 2.58 1.32 4.12 2.61 0.012 0.127
11
Vistula
Tczew
194376.0 2.16 1.03 3.50 2.21 0.007 0.074
12
Dunajec Nowy Targ
(Kowaniec)
681.1 5.04 2.35 9.93 5.24 0.023 0.077
13
San
Przemy´ sl
3686.5 2.83 0.54 6.05 2.85 0.030 0.420
14
Wieprz
Krasnystaw
3001.0 2.06 1.16 2.78 1.86 0.018 0.287
15
Pilica
Przedbórz
2535.9 2.28 1.01 3.75 2.17
16
Narew
Sura˙ z
3376.5 1.21 0.50 2.03 1.05 0.016 0.435
17
Drw˛ eca Elgiszewo
4959.4 2.88 1.16 4.03 2.62
A—catchment area, ALq—specific average minimum flow, LLq—specific lowest minimum flow,
q70%, q95%—specific low-flow threshold (percentile of the flow duration curve); parameters of
statistically significant (α = 0.05) linear trend of multiannual course of minimum flows: a—slope
coefficient, R 2 —determination coefficient
11.3 Minimum Flows
The minimum value of runoff is an integral part of a low flow regime. It indicates limitations during recession of flow on the dry weather curve and very often, the regime
of a basic groundwater aquifer drained by river channels during a drought. Minimum
value may also be modified by such factors as lakes, wetlands, or forest retention.
It may depend on some water management operations, especially downstream of
dammed lakes because of the guaranteed flow.
Distribution of annual flow minima is characterized by strong variation (Fig. 11.2).
The highest minimum specific flow exceeded 10 dm
3 s
−1 km
−2 in Dunajec river
whereas the lowest one reached two orders of magnitude less—0.2 dm
3 s
−1 km
−2 in
Note´ c river. A similar distribution of the Lq at the high average level is observed in
high mountainous and seaside catchments—Dunajec river—Nowy Targ and Wieprza
river—Stary Kraków which indicates that high annual precipitation determines low
flow regime much more than catchment size and its quantity of water resources.