WP 5 Sediment Transport Monitoring

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WPL: Helmut Habersack - BOKU, PP11 WP5 - Content

1. Background

2. Aims and actions

3. Monitoring Methods

4. Study Sites

5. Results and Output

6. Main Achievements/Key findings/ Recommendations

Helmut Habersack, BOKU‐Wien 1. Background

Data on sediment and wood transport is important for: ●Torrent control  hazard protection ●River engineering  flood protection, river degradation ●Construction and operation of hydro-power plants ●Sediment management ●Ecology ●Research  transport processes and variability

Helmut Habersack, BOKU‐Wien Helmut Habersack, BOKU‐Wien 2. Aims and actions within WP5

WP 5 aimed to perform sediment transport monitoring in the Alps, to standardize methods, to analyze measured data and evaluate transport formulas which led to following actions:

5.1 Sediment transport monitoring (suspended load, bedload, debris flows, large wood) 5.2 Standardisation of methods and data collection on sediment transport 5.3 Analysis and assessment of spatial and temporal variability of sediment fluxes at the monitoring sites 5.4 Evaluation and improvement of sediment transport equations and of available numerical models 5.5 Sediment transport monitoring in and evaluation of river restoration projects aimed at enhancing sediment and wood continuity

Helmut Habersack, BOKU‐Wien 3. Monitoring Methods

SedAlp represents the first time coordinated monitoring in the Alpine region of :

●Suspended Sediments

●Bedload

●Debris flows

●Wood transport

WoodNewDrau/Dellach: formedtransport gravel suspendedat the bar Rhône after sediment flooRiverd eventat cloud the 2014, Génissiatmixing Isel with dam– Austria,tributary– – France, BOKU Austria, CNRS BOKU

Rio Chiesa: debris flow event of July 28th 2003 – Italy, ARPAV

Helmut Habersack, BOKU‐Wien  highly suited for measuring this parameter  suited for measuring this parameter  partially suited for measuring this parameter Suspended Sediment - not suited to measure this parameter

Suitability of monitoring methods – part of 1st SedAlp milestone Bottle sampler, BOKU

Monitoring Focused Remote method Bottle Pump Laser Acoustic beam Nuclear Optical spectral sampling sampling diffraction Parameter reflectance reflectance of Interest

Suspended sediment rate         [kg s-1]

Total suspended sediment load         [kg, t]

Spatial variability   - - - - -  of suspended load

Temporal variability of         suspended load

Variation of sediment volume         [m, m³]

Initiation of motion  - -   -  - [m3s-1]

Particle size    - -  - - distribution

Helmut Habersack, BOKU‐Wien  highly suited for measuring this parameter  suited for measuring this parameter  partially suited for measuring this parameter Bedload I - not suited to measure this parameter

Suitability of monitoring methods – part of 1st SedAlp milestone

Monitoring Basket method sampler Basket Bunte traps Monitored (cross sampler (for wadable Slot Trap Retention Geophones Parameter section (repeated) streams) Basin of Interest wise)

Specific bedload rate       [kg m-1s-1]

Bedload rate  -     hydraulic liftable slot sampler [kg s-1] behind geophone installation, Drau/Dellach – Austria, BOKU Total bedload  -     volume [kg, t]

Spatial variability of bedload  -  -   discharge Temporal variability of       bedload discharge

Initiation of motion       [m; m3s-1]

Transport path/ - - - -  - velocity [m; m s-1]

Variation of geophone plates installed in sediment storage ------the Sulden River – Italy, [m, m³] Province of Bolzano

Helmut Habersack, BOKU‐Wien  highly suited for measuring this parameter  suited for measuring this parameter  partially suited for measuring this parameter Bedload II - not suited to measure this parameter

Suitability of monitoring methods – part of 1st SedAlp milestone

Monitoring Terrestrial method Acoustic Aerial Tracers Laser Scour chains pipe sensor imagery Parameter scanning of Interest

Specific bedload rate  - - - - [kg m-1s-1]

Bedload rate   - -  [kg s-1]

Total bedload   - -  volume [kg, t] Searching PIT-tagged tracers with a Spatial variability mobile antenna, Strimm creek - Italy of bedload   - - - discharge Temporal variability of  - - - - bedload discharge

Initiation of motion   - - - [m; m3s-1]

Transport path/ -  - - - velocity [m; m s-1] Terrestrial laser Variation of scanner, sediment storage - -    Hirschbach/Isar – [m, m³] Germany, LfU/kat. U. Eichstätt

Helmut Habersack, BOKU‐Wien Debris Flow I

Suitability of monitoring methods – part of 1st SedAlp milestone

Monitoring method Ultrasonic Fibre optic Radar sensor Laser sensor Geophone Parameter sensor sensor of Interest

Debris-flow      occurrence

Peak flow depth    - -

Debris flow      “hydrograph”

Ground vibration - - -  -

Mean flow velocity, peak      discharge and volume ultrasonic sensor, radar sensors and rain gauge, monitoring station Réal S1 – France, Irstea Surface velocity - - - - -

 highly suited for measuring this parameter  suited for measuring this parameter  partially suited for measuring this parameter - not suited to measure this parameter

Helmut Habersack, BOKU‐Wien Debris Flow II

Suitability of monitoring methods – part of 1st SedAlp milestone

Monitoring Doppler method Video- Wire sensor Pendulum Microphone speedo- camera Parameter meters of Interest

Debris-flow    -  occurrence

Peak flow depth  - - - 

Debris flow video camera with spotlight - - - - - “hydrograph” Gadria catchment, Italy - CNR

Ground vibration - - - - -

Mean flow velocity, peak - -  -  discharge and volume

Surface velocity - - -  

 highly suited for measuring this parameter  suited for measuring this parameter pendulum installed in a channel to  partially suited for measuring this parameter detect debris-flow occurrence, - not suited to measure this parameter Rotolon catchment, Italy

Helmut Habersack, BOKU‐Wien Wood Transport

Suitability of monitoring methods – part of 1st SedAlp milestone

Monitoring Sequences method GPS/RFID Video- Wood Aerial tracking monitoring trapping Parameter imagery of Interest

Wood rate -   - [kg s-1]

Total wood mass -    [kg, t]

Spatial variability    - of wood discharge

Temporal variability of    - wood discharge Initiation of motion [m;  - - - m3s-1]

Variation of wood - - -  storage [m, m³]

 highly suited for measuring this parameter  suited for measuring this parameter  partially suited for measuring this parameter Wood monitoring camera (top) and example - not suited to measure this parameter frame (bottom), Ain/Chazey – France, CNRS

Helmut Habersack, BOKU‐Wien 4. Study sites within WP5

map by Frédéric Liebault

Helmut Habersack, BOKU‐Wien 4. Study sites within WP5

34 highly diverse study sites in the Alpine region

PP1/4- Gadria TLS ● Catchment areas from 0.089 km² (Moulin Ravine at Draix/France) to 10910km² (Rhône River at the Génissiat dam/France) ● Site elevation from 146 m a.s.l (Drôme River at Allex/France) to 2427 m a.s.l. (upper Strimm creek/Italy) ● Channel slopes from 0.18% (Drau River at Dellach/Austria) PP1- Saldur „Bunte“ traps up to 45% (Chiesa Torrent/ Italy) ● Mean flows from 0.011 m³s-1 (Kuzlovec Torrent/Slovenia) up to 356 m³s-1 (Rhône River at the Génissiat dam/France)

PP6- Hirschbachmündung/Isar TLS PP11-Drau Bedload traps and geophone device PP2-Cordon Stream – Monitoring Station

Helmut Habersack, BOKU‐Wien 5. Results and Output of WP5

5.1 Dataset on sediment and wood transport rates and volumes for different regions in the Alps 5.2 Protocol on standardized data collection methods in sediment transport monitoring for transboundary exchange  1st Milestone 5.3 Report on spatio-temporal variability in sediment transport 5.4 Report on opportunities and challenges in improving equations and models for predicting sediment and wood transport rates  3rd Milestone 5.5 Report on the results of the evaluation of restoration projects with respect to measured sediment fluxes

Helmut Habersack, BOKU‐Wien Results and Output 5.1 Intensive monitoring of suspended sediment, bedload, debris flows and wood transport over a period of 34 months

Suspended sediment monitoring example: Bedload transport monitoring example: •Continuous measurements of suspended •specific bedload transport and bedload sediment load (SSL) in the Kuzlovec torrent – texture of an interval bedload measurement Slovenia, UL FGG at the station Lienz/Isel – Austria, BOKU

bedload measurement, Isel 18.06.2013 - specific bedload transport, ]

texture -1 0.326 s

100% 0.350 -1 0.306 0.300 80% 0.250

60% 0.169 0.200

fraction [%] fraction 0.148

0.112 0.123 0.150 40% 0.093 0.094 0.059 0.100 20% 0.036 0.033 0.019 0.050

0% 0.000 specificbedload transport [kg m 19:11 19:21 19:36 19:47 19:57 20:09 20:21 20:28 20:35 20:43 20:54 21:05 time [hh:mm:ss] Stone gG mG fG Sand specific bedload transport

Helmut Habersack, BOKU‐Wien Results and Output 5.1

Debris-flow monitoring example: Wood transport monitoring example: •Debris-flow of March 30, 2013 in the •Cumulated transported distance and mean Réal Torrent – France, Irstea (from velocity of log with GPS_P1 (A) and GPS_T3 (B) Bel et al. 2014). of Piave and Tagliamento River - Italy, UNIPD

Helmut Habersack, BOKU‐Wien Results and Output 5.1 • Detailed description of monitoring results • Datasets for suspended sediment, bedload, debris flows and wood transport monitoring

Example: Debris flows dataset (extract) Rainstorm Mean flow Peak Available Triggering Volume Complementary Catchment Event date duration velocity discharge event rainfall (mm) (m3) data (h) (m/s) (m3/s) images -Pre and post event 14.09.2011 39 0.67 3.6 71 4700(a) None TLS surveys Moscardo 48000- -Pre and post event 24.09.2012 69.8 4.67 3-4(b) 90-120(b) None 65000(b) TLS surveys

79000- -Pre and post event 27.09.2012 92.6 10 3-4(b) 120-160(b) None 105000(b) TLS surveys 11.3 1749 Surge 1: 2.6 -Pre and post event Surge 2: 1.7 4.8 249 Video 05.08.2011 TLS surveys (c) 9.4 5.25 Surge 3: 1.0 3.8 418 -Pre and post event TLS surveys -Post event 18.07.2013 17.2 0.25 5.7 (d) 80-90 10000 Video photogrammetric Gadria survey -grain size analysis of the deposits -Pre and post event TLS surveys 14.07.2014 11.4 0.75 1.4 (d) (e) (e) Video -Pre and post event photogrammetric surveys

Helmut Habersack, BOKU‐Wien Output 5.2 1st SedAlp Milestone: Protocol for data collection method in sediment transport

● Presentation of “state of the art” monitoring technics and data acquisition methods in the Alpine region  Ensures comparability and traceability of monitoring output ● Suitability classification of monitoring methods ● Standardized field forms

1st Milestone available for download at the SedAlp- Homepage (http://www.sedalp.eu/download/reports.shtml)

Helmut Habersack, BOKU‐Wien Output 5.2 Geophone and gauge database query

Main features : ● HTML-based ● Visualization and export of time series of geophone and gauge data for predefined time scales and intervals ● Multiple selection of sensors ● Calculation of time series mean values ● 2 dimensional and 3 dimensional plot of geophone data for the whole cross section ● Interval analysis of geophone data ● Check of database integrity for data gaps

Helmut Habersack, BOKU‐Wien Results and Output 5.3 Report on spatio-temporal variability in sediment and wood transport

Suspended sediment example: Bedload transport example: •typical dynamics of suspended sediment during a •Limitation in sediment supply – Drau/Lienz (top) rainfall event (above, a), showing a counter- •spatial distribution of geophone impulses 2012- clockwise loop (below, b), Saldur River - Italy, 2014, Drau/Dellach (bottom) – Austria, BOKU Province of Bolzano

7% 2012 6% 2013 5% 2014 4% 3%

impulses (%) impulses 2% 1% 0% relative frequency of geophone 1 2 3 4 5 6 7 8 9 10111213141516171819202122232425262728293031323334353637383940 geophone

Helmut Habersack, BOKU‐Wien Results and Output 5.3 Report on spatio-temporal variability in sediment and wood transport

Debris flow example: wood transport example: •Record of debris flows in the Gadria catchment •Relationship between wood density and from historical archives (a) and variability of debris transport ratio, Result from numerical flows in different seasons (b), Gadria Creek - Italy, modelling – France, CNRS Province of Bolzano/CNR

Output 5.3 Report on spatio-temporal variability in sediment transport

Helmut Habersack, BOKU‐Wien Output 5.4 Report on opportunities and challenges in improving equations and models for predicting sediment and wood transport rates  3rd SedAlp Milestone

● Literature review of bedload and wood transport equations and relations ● Application and evaluation of selected bedload and wood transport equations ● Software tool for hydraulic and bedload transport computation

3rd Milestone will be available for download at the SedAlp-Homepage (http://www.sedalp.eu/download/reports.shtml)

Helmut Habersack, BOKU‐Wien Output 5.4 Meyer-Peter & Müller Comparison between calculated (shear stress formulas) and measured specific bedload transport rates, Drau/Dellach – equation: Austria, BOKU dm subsurface Meyer‐Peter, Müller 3 dm bedloadtraps   2.0 1.5 0.5 2 q  8c 0.4

1.5 ] 1  ‐ 1.0 m 0.3

q = Dimensionless bedload transport rate 1 ‐

s 1.0  = Relative shear stress 0.2 [kg

0.5 0.5 c = Shields parameter (critical shear stress) 0.1 = 0.047 (original value)

transport 0.0 0.0

0.0 01234500.511.50 0.1 0.2 0.3 0.4 0.5 Wu et al. bedload q * qs  1.5 1.5 0.5 specific

d gxd 0.4 3 ‐1 ‐1 qs = Specific bedload transport [m s m ] 1.0 1.0 0.3 calculated 0.2 0.5 0.5  Field data needed for selection 0.1

and calibration/validation of 0.0 0.0 0.0 01234500.511.50 0.1 0.2 0.3 0.4 0.5 formulas ‐1 ‐1 measured specific bedload transport [kg s m ]

Helmut Habersack, BOKU‐Wien Output 5.4 - 3rd SedAlp Milestone JAVA based software tool for hydraulic and bedload transport computation – developed by BOKU

● Ensures the standardized application of three bed load transport equations o Meyer-Peter & Müller (1948) o Smart and Jäggi (1983) o Rickenmann (1990) with reduced slope ● Applys the cross section - based engineering method ● Displays parameter and equation validity Computation tool will be available for download at the SedAlp-Homepage (http://www.sedalp.eu/download/reports.shtml)

Helmut Habersack, BOKU‐Wien Results and Output 5.5 Sediment transport monitoring in and evaluation of river restoration projects aimed at enhancing sediment and wood continuity

Output 5.5: Report on the results of the evaluation of restoration projects with respect to measured sediment fluxes

Helmut Habersack, BOKU‐Wien Results and Output 5.5 Example: analyses of River restoration measures at Drau River/Austria, BOKU •Long term river bed degradation in the past decades •Realisation of various river restoration measures •Analysis of long term development and impact of sediment discontinuities in upper catchment

Impacts of transverse structures on the sediment continuity for the catchment of the Upper Drau River. About 69% of the entire catchment is more or less detached from the downstream area.

Development of the River restoration at Kleblach from 1999 (regulated condition) until 2010

45000

40000

35000

30000

25000

20000

15000 Sedimentbudget in m³ Sedimentbudget

10000

5000

0 2001 Jun 2003 Jul 2004 Jul 2005 Jul 2006 Jul 2007 Oct 2008 Oct 2009 Spring 2011

River bed degradation Drau Sediment budget for the River restoration of Kleblach

Helmut Habersack, BOKU‐Wien Results and Output 5.5 Example: sediment input at the Isar/Germany, LfU/kat. University of Eichstätt: •Sediment deficit due to Sylvenstein reservoir

Sediment input site downstream the 3rd sill at the Sylvenstein reservoir at different time steps, Isar - Germany

Digital elevation model (DEM) of the 3rd sill development between October 2013 and August 2014 from

Helmut Habersack, BOKU‐Wien 6. Main Achievements

● First time coordinated sediment and wood transport monitoring in the Alpine region ● Large new set of sediment and wood transport data ● First time standardization of methods and data collection on sediment and wood transport in the Alpine Space  1st milestone ● Comparison of field data with bedload and wood transport equations ● Computation tool for the standardized application of three bedload equations

Helmut Habersack, BOKU‐Wien Recommendations Policy Makers: • Sediment transport monitoring data should be managed, stored and quality assured by a public hydrographic service • The accessibility of validated sediment transport data should be assured for practitioners (administration, consulting companies, hydropower companies, navigation, NGOs and qualified public) • To improve long term data bases on sediment transport, particularly in catchments where the sediment management is a main topic as in those strongly influenced by hydropower exploitation and hydrogeological risk mitigation measures • Monitoring stations for sediment transport managed by Public Agencies should be located in channel sections either suitable to perform a sound sediment budgeting of relevant catchments, or featuring special characteristics to investigate special processes of interest for the administration (e.g. related to hazards or to ecological dynamics) • Establishment of a network of similar sediment and wood monitoring stations among the same country and also throughout transboundary collaborations and interchange in order to share data and experiences about sediment and wood monitoring and management

Helmut Habersack, BOKU‐Wien Recommendations Policy Makers: • Although implementation of a large number of monitoring stations is unrealistic due to economic and logistic constraints, the continuation of monitoring activities in currently operating sites, and the installation of simple, inexpensive equipment in a few new sites of particular relevance could be envisaged • Establishment of training possibilities for state of the art monitoring (hydrographic services), right use of this data for practitioners • Implementation of sediment monitoring and analyses techniques into lecturing at universities should be improved • Guarantee of the availability of skilled personnel to perform measurements at extreme flood is of utmost importance for collecting data on low-frequency, high-magnitude events. • Improvement of the links between research an application/management with respect to “immediate” knowledge and technic transfer from basic research to practice

Helmut Habersack, BOKU‐Wien Recommendations Practitioners: • Combination between direct and indirect suspended, bedload, debris-flow and wood monitoring techniques is required to gain representative field data • In order to compare monitoring results across the Alps, harmonized monitoring techniques and protocols should be used • The availability Meta-data of monitoring instruments at study sites is essential • The monitoring of sediment and wood transport should be carried out utilizing the most recent/advanced state of research in the topic (instruments and methods) • Signal deriving from seismic/acoustic sensors (i.e. geophone plates, acoustic pipes, etc..) should be collected either as the entire wave (but potential problems with large data storage) or by registering the number of impulses exceeding a given threshold adopting different amplifications values of the signal • For the sediment balance, flood events are very important. The monitoring techniques should contain a continuous, automatic monitoring system in order to guarantee that especially flood events are measured with the requested accuracy • A standardized analysis procedure is suggested, e.g. the determination and application of correlation functions between direct and indirect monitoring methods (e.g. regression analysis, fitting to probes - suspended sediment) • Establishment of training possibilities for state of the art monitoring (hydrographic services), right use of this data for practitioners

Helmut Habersack, BOKU‐Wien Recommendations Practitioners: • In advance definition of specific sediment monitoring programs for (extreme) flood events, e.g. additional sampling spots for suspended and bedload monitoring beside the standard monitoring sites • Guarantee of accessibility and functionality of sediment monitoring stations during (extreme) floods • The presence of a retention basin downstream of the monitoring installation is ideal for measuring/estimating the debris flow volume through indirect methods (use of ultrasonic/radar sensors, geophones, etc.) and for calibrating and improving these latter for research purposes (e.g. Gadria monitoring site) • A monitoring/recording equipment for debris flows using geophones should have the possibility to change the signal amplification of each geophone via software to take into account its position on the ground and its distance from the channel • A monitoring/recording equipment for debris flows should be designed to work stand alone, to allow its installation in every possible field condition • Practical application of sediment and wood transport equations need to be selected based on and calibrated and validated using monitored field data • The application of sediment transport equations has to be carried out with great caution, especially at low to medium flows where large overestimations are very likely and different transport rates are common under similar flow conditions; • Calibration of equations against field data (e.g. incipient motion thresholds, transport rates at low flows) is strongly suggested to reduce the errors (which otherwise can be up to several orders of magnitude)

Helmut Habersack, BOKU‐Wien Recommendations Practitioners: • Besides the formula selection and calibration process, numerical sediment transport models need also to be calibrated and validated against field data • The design of River restoration measures should be based on an improved process understanding between sediment transport an engineering measures • It should be checked how to extend the success and the sustainability of River restoration measures depending on the functioning of sediment regime, input and output • Potential channel adjustment to restoration measures must be assessed within a risk analysis to better consider their consequences (locally, upstream and downstream) and their potential efficiency and sustainability • The interaction of River restoration with regulated reaches and especially upstream structures, eventually disrupting the sediment continuum, have to be analysed and counter measures suggested

Helmut Habersack, BOKU‐Wien Recommendations Research: • In order to capture global or regional changes (e.g. climate change, land use change), long term sediment monitoring programs should be established at least at a minimum, representative field stations • The methods currently available for geophone data processing (method of amplitude, method of impulses, etc.) should be implemented on board on the recording/monitoring equipment adopted to allow a comparison of the performances of the methods and to better exploit the peculiarities and advantages of each method • Integrating monitoring of debris flows at instrumented cross-sections with observations on sediment sources evolution and channel changes by means of photogrammetry, terrestrial laser scanning and aerial laser scanning would permit maximizing the benefits and overcoming the limitations of individual approaches • The importance of integrating debris-flow monitoring with suspended load and bedload measurement should be stressed • The strong links between the various processes responsible for sediment delivery at catchment scale and stresses out the need for a closer integration between the monitoring of various sediment transport processes in Alpine headwaters

Helmut Habersack, BOKU‐Wien Thank you for your attention!

Helmut Habersack, BOKU‐Wien