Prediction of fluvial processes change within mountain streams on the example of the Porębianka stream Andrzej Strużyński*, Maciej Wyrębek*, Małgorzata Leja* Krzysztof Kulesza**, Ilona Biedroń** * University of Agriculture in Kraków ** Institute of Metheorology and Water Management
Presentation schedule 1. Basin description 2. Porębianka stream 3. Flow data 4. Methodology 5. Results 6. Results interpretation 7. Additional solutions 8. Conclusions
1. Basin Porębianka is a stream flowing in the Gorce Mountains. It is a left tributary of the Mszanka River. Sources of the stream are located in Pośrednie col between Obidowiec and Bardo Mountains (13 m a.s.l.). Area of basin is 71 km2 and the length 15 km. It can be stated that afforestation had increased here from 49.2 % in year 1984 to 59% in 23. 3 / 34
1. Basin reaches reach 1 - korekcja progowa sub-basin1 A1 = 33.6 km2 slope (middle part) S =.9% slope (lower part) S =.1% reach 2 - Zmysłówka sub-basin2 A2 = 63.5 km2 slope high water S = 1.8% slope low water Sr = 7.9% Sp =.8% reach 3 przy rampach sub-basin3 A3 = 67.7 km2 slope high water S = 1.9% slope low water Sr = 6.% Sp =.14% basin total area 3 2 1 A = 71 km2 Niedźwiedź water gauge sub-basin A = 61.7 km2 4 / 34
1. Basin reach I - river is regulated by series of small steps 5 / 34
1. Basin reach II - river banks are stabilized 6 / 34
1. Basin reach III - river is regulated by ramps 7 / 34
2. Porębianka Stream reach I, cross-section 1 - river is regulated by series of small steps 8 / 34
2. Porębianka Stream reach I, cross-section 2 - river is regulated by series of small steps 9 / 34
2. Porębianka Stream reach I, cross-section 2 - river is regulated by series of small steps 1 / 34
2. Porębianka Stream reach I, cross-section 3 - river is regulated by series of small steps 11 / 34
2. Porębianka Stream below reach I, bridge in Niedźwiedź rocky bed 12 / 34
2. Porębianka Stream below the outlet of the Konina Stream 13 / 34
2. Porębianka Stream reach II (Zmysłówka) - river banks are stabilized 14 / 34
2. Porębianka Stream reach II (Zmysłówka) - river banks are stabilized 15 / 34
2. Porębianka Stream reach III - river is regulated by ramps 16 / 34
2. Porębianka Stream reach III - river is regulated by ramps 17 / 34
2. Porębianka Stream Porębianka p. K. reach III - river is regulated by ramps 18 / 34
3. Flow data p% Niedzwiedź water gauge.1.2.3.5 1 2 3 4 5 1 2 25 3 4 5 273 245 229 29 181 153 136 124 115 85.7 56.7 47.5 4.4 3.1 25 source: IMGW, reach I reach II Q [m3/s] 149 277 134 249 125 233 114 212 99 184 83 155 74 138 68 126 63 117 47 87.1 31 57.7 26 48.4 22 41.2 16 3.8 14 25.6 reach III 288 259 242 221 191 162 144 132 122 91.2 6.6 5.9 43.3 32.5 27 calculated with Punzet equation probability of the maximum annual peak discharges 19 / 34
4. Methodology 1. In situ measurements 29 214 - geodesy measurement (long. profiles, cross-sections) - granulometry - photos Assumption steady state 2. HEC-RAS 3. Konsum, Chezy Manning eq. 4. Armour, Wang, Bartnik, Gessler, Komura eq-s 5. Incipient motion bed stability prognosis 2 / 34
Lp h[m] H[m] 4. Methodology Q[m3/s] v[m/s] A[m2] B[m] Ozw[m] Rh[m] 874.1.29 874.129.1.197.5.37.314.14 2.59 HEC-RAS 3.88 Konsum 874.159.6.313.18.615.628.29 874.188.17.411.41.922.942.43 1 4.118 874.218.36.497.72 1.23 1.256.58 5.147 874.247.65.577.113 1.537 1.57.72 6.177 874.277.16.652.163 1.845 1.884.86 7.26 874.36.16.722.222 2.152 2.198.11 8.236 874.336.229.79.29 2.46 2.512.115 9.265 874.365.313.854.367 2.767 2.826.13 1.294 874.394.417.922.453 3.45 3.113.145 11.324 874.424.551 1.13.544 3.159 3.246.168 12.353 874.453.71 1.98.639 3.272 3.379.189 13.383 874.483.854 1.159.737 3.468 3.595.25 14.412 874.512.925 1.84.853 4.461 4.63.185 15.442 874.542 1.55 1.55.999 5.454 5.612.178 16.471 874.571 1.314 1.126 1.167 5.767 5.95.196 17.51 874.61 1.636 1.222 1.338 5.811 6.24.222 18.53 874.63 1.984 1.314 1.51 5.856 6.98.248 19.559 874.659 2.358 1.42 1.683 5.91 6.172.273 2.589 874.689 2.758 1.485 1.857 5.946 6.246.297 21.618 874.718 3.181 1.565 2.33 5.993 6.321.322 22.648 874.748 3.627 1.641 2.21 6.42 6.399.345 23.677 874.777 4.96 1.714 2.389 6.92 6.476.369 24.77 874.87 4.587 1.785 2.569 6.142 6.553.392 21 / 34
4. Methodology reach I p49.5 p II rating curves reach 3 I p3 P III reach II Zmysłówka reach III Godki 2.5 h [m] 2 1.5 1.5 2 4 6 8 1 12 14 16 18 2 Q [m3/s] 22 / 34
4. Methodology reach I p49.5 P II water depth for Q% reach I p3 P III 3 reach II Zmysłówka reach III Godki 2.5 h [m] 2 1.5 1.5 5 1 15 2 25 3 35 4 45 5 Q% 23 / 34
4. Methodology d q (d ) p (d ) pa (d ) d min d max q (d ) p (d ) d min gr qg p 24 / 34
4. Methodology 25 / 34
5. Results measured 1..77 9. 1.4 1.43 8. 1.64 1.6 7. 1.69 Ʃp % 6. 5. 4. 3. 2. 1....2.4.6.8.1.12.14.16.18 d [m] reach I, cross-section 2 armour coat up to Q5% 26 / 34
5. Results measured.59 1..79.99 9. 1.19 1.48 8. 1.86 2.9 2.35 7. 2.5 Ʃp % 6. 5. 4. 3. 2. 1....2.4.6.8.1.12.14.16.18 d [m] reach I, cross-section 3 armoring processes coat up to Q1% and higher 27 / 34
5. Results 1 9 8 7 6 measured.76.98 1.27 1.76 Ʃp % 5 4 3 2 1.2.4.6.8.1.12.14 d [m] reach II bed not stable high transportation reach 28 / 34
5. Results 1 9 8 7 measured.4.5.75 1.1 6 Ʃp % 5 4 3 2 1.2.4.6.8.1.12 d [m] reach III armour coat up to Q35% (dominant discharge often meets Q75%) 29 / 34
6. Results interpretation Konina sub - basin bedload alimentation weak due to regulation structures and increased afforestation 3 / 34
6. Results interpretation fluvial processes are currently poorly balanced reach I, cross-section II low transport potentials reach I, cross-section III no transport potentials Konina stream low bedload supply reach II high transport potentials -> high bed erosion reach III average transport potentials 31 / 34
7. Additional solutions after removing regulation structures in the highest reach (I) 1 9 8 7 measured.77 1. 1.16 1.26 1.39 1.52 5 4 3 1 2 9 1 8.2.4.6.8.1.12 7.16.14 Q25% measured.62.82 1.1 1.15 1.31 1.41.18 6 d [m] Ʃp % Ʃp % 6 5 4 3 bedload alimentation potentials dramatically increased 2 1 less than Q5%!!!.2.4.6.8.1.12.14.16 d [m] 32 / 34.18
8. Conclusions 1. Regulations, especially done in the highest reach, destroy river continuity 2. At present high erosion processes appear in transportation reach II from the end of reach I to reach III, especially below outlet of the Konina stream 3. Within reach III effects of decreased bedload alimentation are reduced by ramps 3. After removing of the small steps from reach I much more intensive fluvial processes would appear - this could improve the bed condition in reach II but also - could also start high movement of bedload and bed erosion within the lower part of reach I 33 / 34
Thank You 34 / 34