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Sustainable Hydropower In Alpine Rivers Ecosystems Philippe Belleudy, Hernn Alcayaga PP9 Laboratoire dtude des Transferts en Hydrologie et Environnement Universit Joseph Fourier Grenoble 1 GESTRANS 22 novembre 2012 Slide 2 page 2 Morphodynamics and their large scale/slow working impacts 1.SHARE Objectives, partnership, work packages Results 2.Integration of morphodynamics within SHARE method : why and how 3.Modelling morphodynamics at basin scale The idea The test case After SHARE Slide 3 page 3 1. SHARE objectives Balancing river ecosystems and hydropower requirements River users and defenders face a daily contradiction, notably in implementing both the Directive on Electricity Production from Renewable Energy Sources and the Water Framework Directive. The purpose of SHARE is to develop, test and promote a decision support system (DSS) to merge, on an unprejudiced base, both river ecosystems and hydropower requirements. Arc River (upstream) Barrage de la Girotte (doc.M.Pila) Slide 4 page 4 1. SHARE partnership 13 partners Universities, local authorities, NGOs, hydropower companies Leaded by ARPA Valle dAosta 5 countries different domain of expertise River morphology from LTHE Slide 5 page 5 1. SHARE results Deliverables A method / a tool / a handbook / databases A set of generally applicable and comparable indicators & monitoring standards Regional cooperation Pilot case studies A strong limitation for an efficient development For us End user justification of our basic research Partnership http://www.share-alpinerivers.eu Slide 6 page 6 2. MORPHODYNAMICS : why ? Source:WFD guidance doc #10 WFD and morphodynamics 1.Good ecological status may be reached even with bad morphological conditions! Slide 7 page 7 2. MORPHODYNAMICS : why ? WFD and morphodynamics 1.Good ecological status may be reached even with bad morphological conditions! 2.Simplistic, it hardly takes into account the transformations at long time scale Drac River (upstream) Slide 8 page 8 limits of the active bed before HP equipment 2.Simplistic, it hardly takes into account the transformations at long time scale Drac River (downstream) Slide 9 page 9 limits of the active braided bed before HP equipment 2.Simplistic, it hardly takes into account the transformations at long time scale Drac River (downstream) Slide 10 page 10 2. MORPHODYNAMICS : how ? A pre-processor has been developed for the assessment of morphological changes Integration within SHARE method Alt. 1 Alternatives Alt. 2 Alt. n :::: Production dlectricit Apport a la matrice des nergies renouvelables Qualit Biologique Qualit Physique - Chimique Qualit Hydro - morphologique Sub-criteria Qualit de milieu aquatique Energie Criteria rate ! Rating AGREGATION Indice daltration de dbit Indice de poisson Condition de nutriments Indice de continuit de la rivire Quantit de llectricit gnre par anne Indice de diatomes Indice defficience de production dlectricit Condition doxygne SESAMO indicators Condition de temprature erosion/deposition wider/narrower finer/coarser Slide 11 page 11 3. Modelling morphodynamics at basin scale 3.1The idea 3.2The method 3.3Explained thru the Isre test case 3.4After SHARE Alcayaga H., Belleudy, Ph, Jourdain, C. - Morphological modeling of river perturbations due to hydroelectric structures at watershed scale RiverFlow 2012 Slide 12 page 12 3.1. The idea (1/2) river conditions are made by upstream driving factors 1.flow regime 2.sediment sources from upstream reaches and lateral watersheds Schematization of the trajectories from state A to state C or C in response to two permanent disturbances of the control factors with different magnitudes (adapted from Werritty, 1997). The modeling is based of the alteration of an existing dynamical equilibrium controlled by the u/s driving factors : hydrology + sediment input conditioned by local physical characteristics Slide 13 page 13 3.1. The idea (2/2) upstream perturbations of the driving factors propagate downstream concerning bed-load and bed transformation : it needs time ! The Ubaye R. sweeps down solid material deposited at the outlet of its tributaries a conceptual modeling at basin scale [1000- 30000 km] at engineering time scale [10-1-10 yr] based on expert knowledge Supported by a GIS description of the watershed Slide 14 page 14 3.2. The method (1/4) Index for alteration of the hydrological regime From flow duration curves Using a reference morphological discharge Slide 15 page 15 3.2. The method (2/4) Index for alteration of the sediment sources Sediment supply index (9 classes) Alteration of the sediment continuity Pente du terrain (0X0) [5] Couverture vgtale (00X) [5] Combinaison et reclassement (XXX) classes qui sont reclasses dans 9 catgories. Type de roche (X00) [3 ] = Q in, pre SS in, pre Q out, pre SS out, pre Q in, post SS in, post Q out, post SS out, post Slide 16 page 16 Morphodynamics and their large scale/ slow working impacts 3.2. The method (3/4) : integration of expert knowledge decreased cross-section area increased/decreased w increased/decreased d increased bed level (aggradation) disappearance terrace deposition in pools deposition in riffles channel instability incision wider and deeper channel increased w increased d increased/decreased s increased/decreased d50 increased/decreased w/d increased the wavelength of the meander increased/decreased %silt and clay increased the cross-section area increased/decreased w increased/decreased d bed level: aggradation disappearance of terrace deposition in riffles erosion/deposition in pools Channel aggradation vegetation encroachment Textural shifts at confluences Island and bar construction diminution the cross-section area increased/decreased w increased/decreased d aggradation formation of terrace erosion/deposition of riffles deposition in pools deposition decreased channel capacity (w*d) decreased channel width (w) deposition decreased channel capacity (w*d) decreased channel width (w) diminution du profil en travers diminution/augmentation de w diminution/augmentation de d pas de changement en le niveau du lit A/D ou faible de dgradation formation de terrasse rosion de rapides rosion/dpt en mouilles decreased the cross-section area decreased w decreased d Not changes in the bed level (A/D) formation of terrace erosion de riffles deposition in pools bed scour armored channel bar and island erosion channel degradation, narrowing increased the cross-section area increased/decreased w increased/decreased d degradation disappearance terrace erosion/deposition in riffles erosion pools aggradation decreased w decreased d increased s decreased d50 decreased /increased w/d decreased the wavelength of the meander decreased sinuosity increased %silt and clay channel instability narower and deeper channel Processes decreased in intensity decreased w increased/decreased d decreased s increased/decreased d50 increased/decreased w/d decreased wavelength of the meander increased sinuosity decreased %silt and clay accommodation not changes in channel capacity (w*d=cte) redistribution decreased the channel capacity (w*d) decreased channel width (w) channel instability incision deeper, wider? channel increased w increased d decreased s increased d50 decreased/increased w/d increased the wavelength of the meander increased sinuosity decreased %silt and clay increased the cross-section area increased w increased d no changes in bed level A/D disappearance of terrace deposition into the riffles erosion of pools processes increased in intensity Grant, 2003 and 2012 Schumm, 1969 and 1977 Petts, 1980 Kellerhals & Church, 1989 Brandt, 2000 Lane, 1955 Williams & Wolman, 1984 Dust & Wohl, 2012 channel instability aggradation wider and shallower channel increased w decreased d increased/decreased d50 increased/decreased w/d decreased sinuosity decreased %silt and clay Slide 17 D: degradation; A: aggradation; =: invariable; +: increased; -:decreased; +/-: increased or decreased; Y: occurrence of phenomena; N: non occurrence of phenomena; Y/N: occurrence or non occurrence of phenomena * * according to Schumm (1969) and Huang and Nanson (2002) * 3.2. The method (4/4) A vector : direction + amplitude 10 morphological indicators Aggradation / Slope / width / depth / d50 Slide 18 page 18 3.3. Pilot Case Study : a proxy of Arc-Isre basin 5500 km HP stuffed Calculation of the morphological impact of HP equipment Assuming a pristine equilibrium just after WW2 Unvalidated and simplifed data Slide 19 page 19 3.3. Pilot Case Study : Arc-Isre basin 25 sub basins and reaches river typology watershed sediment production nodes : tributaries, plants and dams Slide 20 page 20 3.3. Pilot Case Study : Arc-Isre basin alteration the flow regime FQ Slide 21 page 21 3.3. Pilot Case Study : Arc-Isre basin alteration the sediment sources AS Slide 22 page 22 3.3. Pilot Case Study : Arc-Isre basin FQ and AS for 25 sub-basins and reaches Slide 23 page 23 3.3. Pilot Case Study : Arc-Isre basin FQ and AS for 25 sub-basins and reaches (1) (3) (2) Slide 24 page 24 3.3. Pilot Case Study : Arc-Isre basin closer for 3 examples-reaches 45 FQ (1) 135 225 AS 180 (2) (3) 270 Trends 1.Aggradation, steeper slope, decrease of w, d, C, probable siltation and colonisation of the vegetation on bars. 2.Chanel erosion, milder slope, 3.Xxx Slide 25 page 25 3.3. Pilot Case Study : Arc-Isre basin - validation Peiry et al., 1994. Lincision des rivires dans les Alpes franaises du nord : tat de la question. Coherent ! Bed degradation [1950_1980] Combined effect of gravel mining d/s Slide 26 page 26 3.5 After-SHARE (1) discussion Isere-like No contract / no data / no details Designed to cost Validation Calculation of sediment supply A rough schematization of transport and morphological processes Suspended load Vegetation Slide 27 page 27 3.5 After-SHARE (1) discussion 1. Isere-like 2.Designed to cost 3.At basin scale : not for detailled assessment 4.A rough schematization of transport and morphological processes 5.The diversity Slide 28 page 28 3.5 After-SHARE (2) next to come ! 6.Transient effects and superposition of perturbations Gregory 2006, adapted from Graf (1977) and Schumm (1979). Slide 29 page 29 3.5 After-SHARE (2) next to come ! 6.Transient effects and superposition of perturbations Pente final Pente initial V(t=1) V(t=2) V(t=n) t=1t=2 t=n temps volume (v) - 10 00020 00030 00040 00050 000 500 460 420 380 340 300 260 220 180 140 100 60 20 volume charri (m3) Slide 30 page 30 3.5 After-SHARE (2) next to come ! 7.Adapted to other impacts Gravel mining Climate change Available for Slide 31 page 31 Summary 1.SHARE A good idea Mitigated in term of scientific results 2.morphodynamics and must be considered when assessing the ecological status of rivers 3.modelling morphodynamics at basin scale An opportunity A method which has been validated The after-SHARE is focussed on dynamics Philippe BELLEUDY Laboratoire dtude des Transferts en Hydrologie et Environnement philippe.belleudy@ujf-grenoble.fr| +33 476.635.662 vielen Dank fr Ihre Aufmerksamkeit ! Slide 32 page 32 1.Morphodynamics are important issues for river ecology, for HP production 2.A slow working process, at basin scale morpho assessment may be complex 3.Integration of morphodynamics within SHARE method 4.Pilot Case Study : Arc-Isre testing morphodynamics SHARE potential at basin scale Zusammenfassung Philippe BELLEUDY Laboratoire dtude des Transferts en Hydrologie et Environnement philippe.belleudy@ujf-grenoble.fr| +33 476.635.662 vielen Dank fr Ihre Aufmerksamkeit !