The extensive monitoring of suspended sediments by means of ultrasound (an ADCP application)

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1 Best practices for hydropower reservoir sediment management 31May 1June 01, Venice, Italy The extensive monitoring of suspended sediments by means of ultrasound (an ADCP application) Dr. Massimo Guerrero

extensive monitoring of suspended sediments by

2 Presentation contents The acoustic multi-frequency method The Laboratory tests River-channel sediment monitoring at fixed positions and from moving boat A possible application within a project for sediment flux restoring across a multi-use reservoir

positions and from moving boat A possible application within a

3 The SONAR equation Emitted intensity + Noises = Received intensity + losses TS=RL+TL-SL log(m σ)

4 Method applicability Scattering size and backscattering sensitivity 3 a f ; x a x=1.00 x=0.8 khz (5%) (5%)

5 Method calibration ) ( 73.16) ( log r c v E E K R P L R T C S RDI-ADCP sonar equation ) ( 73.16) ( log log r c s E E K R P L R T C f a M Concentrations-grain size products y-axis: acoustic inferred data x-axis: known data K c is mainly an electro-acoustic parameter C is mainly an environment parameter

16) ( log 10 8 10log 10 1 10 r c s E E K R P L R T C f a M Concentrations-grain

6 Grain size and concentration assessment TS 1 =RL 1 +TL 1 -SL 1 log(m σ 1 ) freq. 1 TS =RL +TL -SL log(m σ ) freq. 3 a f

7 Tower tank tests Laboratory tests

8 Tower tank tests Simplified approach aiming to overcome air bubbles noise trapped within water volume TS 1 TS log f f 1

9 Tower tank test results

10 The Parana river case study m 3 /s Mean discharge 130x10 6 t/year Total load 100 ug/l Wash load 0 mg/l Suspended load mg/l Bed load

11 Method validation 600 and 100 khz RDI-ADCP calibration on water samples at fixed position Cross-section P4 P1 Depth averaged echoes vs. single sample TS

12 Observed variability at fixed positions

13 Sediment investigation at cross-section Sediment concentration Grain size

14 The Po river application

15 The mapping toolbox Kriging predictor mesh depth averaged velocity fluctuation

16 Velocity field results Depth averaged velocity friction velocity map Friction velocity ADCP profile fitting

17 Concentration & grain size distributions Bathymetry Sedimentology results

18 Sediment flux restoring at Castellarano reservoir (Secchia river) portata [mc/s] m 3 /s durata [giorni in un anno]

portata [mc/s] 50 00 150 50 m 3 /s 100 50 0

19 Sediment channel project T Traversa d SCALA 1:00 SCALA 1: Sezione A customized multi-frequency ADCP in fixed position nearby the Castellarano dam Sezione 5 Sezione 4 Sezione 3 Sezione Sezione Quote Terreno Naturale (m) 153,0 153,0 15,90 151,70 150,75 150,10 150,40 149,30 145,85 Distanze Parziali (m) 3, 90,3 173,3 19 8,7 94,5 6 66, acqua limi e argille ghiaie e sabbie livello di massimo invaso livello di massima piena progetto traversa Castellarano livello di massimo invaso ghiaie (sabbia <0%) ghiaie (sabbia < 5%) terrazzi più vecchi livello di massima piena Qp=1750 mc/s /1 bedrock / / / SCALA 1:00 Quote Terreno Naturale (m) SCALA 1: sinistra idraulica Reggio Emilia s.p. di Castelvecchio Destra idraulica Modena Distanze Parziali (m) 30 19,64 1,3 36,11 31, 0,95 7,34 73,33 1,57 18,37 79,6 4,99 88,3 11, , ,4 9,48 7,66 7,9 8,67

85 Quote Terreno Naturale (m) 153,0 153,0 15,90 151,70 150,75 150,10 150,40 149,30 145,85 Distanze Parziali (m) 3, 90,3 173,3 19 8,7 94,5 6 66, 105 67 68 161 7 58 acqua 157.0 157.60 157.

20 Conclusions The multi-frequency method using ADCPs provide concurrent and detailed data regarding flow velocity and sediment transport The method was proved to give reliable result both in fixed positions for time series investigation or by deploying the equipment from a moving boat to map the velocity and suspended sediment fields Extensive monitoring of suspended sediment concentration and grain size could help in the operations program at reservoirs in order to limit sediment settling

by deploying the equipment from a moving boat to map the velocity and suspended sediment fields Extensive monitoring of

21 1. Guerrero M., Ruther N., Szupiany R. Laboratory validation of ADCP techniques for suspended sediments investigation. Journal of Flow Measurement and Instrumentation, 3 (01) Guerrero M., Lamberti A. Flow Field and Morphology Mapping Using ADCP and Multibeam Techniques: Survey in the Po River. J. Hydraul. Eng., 137(1) Guerrero M., Szupiany R, Amsler M. Comparison of acoustic backscattering techniques for suspended sediments investigation. Journal of Flow Measurement and Instrumentation (011) Guerrero M., Di Federico V., Lamberti A. Improved calibration of a -D numerical model of Po River morphodynamics using MBES and ADCP measurements, J. Hydroinform., under review. 5. Guerrero M., Szupiany R. Validation and application at the Parana River of the Multi-frequency method for suspended sediments investigation. To be soon submitted Dr. Massimo Guerrero Hydraulic Laboratory - DiCAM tel.: ; massimo.guerrero@unibo.it

Index-Velocity Rating Development (Calibration) for H-ADCP Real-Time Discharge Monitoring in Open Channels

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