Life EBRO-ADMICLIM: Adaptation and mitigation measures to climate change in the Ebro Delta

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1 Life EBRO-ADMICLIM: Adaptation and mitigation measures to climate change in the Ebro Delta Dr. Carles Ibáñez IRTA Aquatic Ecosystems Program 04/12/2014 0

2 Summary 1) Global change pressures in deltas 2) Adaptation options 3) Mitigation measures 4) Life EBRO-ADMICLIM: actions to be implemented 5) The RISES-AM project: main goals 04/12/2014 1

3 XX Aniversari CIIRC The case of deltas: vulnerability & socio-ecological values Deltas represent 1% of the Earth surface but more than 500 million live in!!! , , , Km. 0 2, Elevation (m) 0-0,5 0,5-1,0 1,0-1,5 04/12/ , , ,5-2,0 2,0-2,5 2,5-3,0 3,0-3,5 3,5-4,0 > 4, ,000000

4 XX Aniversari CIIRC The impacts of climate change: sea level rise 04/12/2014 3

5 Expected sea-level rise beyond the present century Source: Jevrejeva et al. (2012): Sea level projections to AD2500 with a new generation of climate change scenarios. Global & Planetary Change 80-81:

6 Relative sea level rise in the Ebro Delta Its low elevation (0-3 m), makes the delta vulnerable to RSLR. Subsidence rates have been estimated t to be 1-5 mm/yr dependingdi on local l features. Sea level rise rate is now about 3 mm/yr, and will keep increasing during the present century. Relative sea level rise in the Ebro delta is expected to reach between 0.6 to 1 m at the end of the century, causing about 50% of the delta to be below sea level. l

7 Flooding risks Flood hazard areas (in blue) to RSLR of 0.25 m (left) and 0.5 m (right) at the Ebro delta. Source: Alvarado-Aguilar and Jiménez

8 The impacts of damming: sediment retention The Ebro Delta has a watershed with a Mediterranean climate in which large river floods with a high suspended sediment load were usual before and after human intervention. Values from 0.1 to 10 g/l were usual in the Ebro River before dam construction (Ibañez et al. 1996). Only recently, after 1960 s the Ebro River has undergone a dramatic reduction of sediment fluxes (up to 99%) due to dam construction. Suspended sediment load is presently <0.01 g/l (Rovira et al. 2012). Nowadays the delta has very little protection infrastructures against coastal and river flooding due to the fact that most of the delta is still above sea level, and the storm surge and river floods are not a serious threat. Only very large floods ( yr return period) have the chance to flood the delta plain. Ibáñez, C., Prat, N. and Canicio, A. (1996). Changes in the hidrology and sediment transport produced by large dams on the lower Ebro river and its estuary. Regulated Rivers 12(1): Rovira, A., Alcaraz, C. & Ibañez, C. (2012). Spatial and temporal dynamics of suspended load at-a-cross-section: The lowermost Ebro River (Catalonia, Spain). Water Research 46:

9 Coastal retreat in the Ebro Delta picture 2000

10 Year 1990 Year 2004 Year 2015 Year 2025 Year 2035 Year 2045 E t d t l Expected coastal retreat in the Ebro Delta

11 Adaptation of deltas to sea level rise: natural mechanisms

12 Adaptation options for sea level rise & sediment deficit - The current approach (structural): rising dikes (The Netherlands). - The alternative approach (functional): rising grounds (Ebro Delta). - The combined approach (structural & functional): rising dikes & rising grounds (Mississippi Delta). The current view is that protection is the best (or the only) strategy for future SLR up to 2 to 5 meters. Beyond 5 meters the retreat would be the best (or the only) strategy (Tol et al. 2006). The alternative view suggest that rising dikes will be only feasible if rising grounds is also implemented; if not, retreat will be the only solution in the longrun. Rising grounds could be the main strategy in most deltas. We propose that rising grounds is the best adaptation strategy in most deltas for high-end scenarios of SLR, though in some cases the option of retreating may be necessary in combination with structural and functional measures. The different options should be applied as a function of the natural and human features of deltas (population and urbanisation level, l availability of sediment sources, local rates of relative sea-level rise, etc.).

13 The functional protection strategy: the case of the Ebro Delta During the last century most of the delta was devoted to rice farming and the farmers were promoting the sediment inputs to the rice paddies in order to improve rice production. The rice system was very efficient at distributing riverine sediments, and it may be used in the future provided we recover at least part of the sediment flux. In fact, most of the rice fields were created in the XIX century through engineering projects designed to bring riverine sediments to the salt marshes. This is a nice example of classical ecological engineering and ecosystem service! Mister Polet and the old culture of sediment (and water) management in the Ebro Delta. He still remembers the practice of silting, in which farmers were paying a tax to the irrigation company to be able to get sediments after the rice harvest. After the deposition, there was a hard work with man power and horse power to distribute the sediments.

14 Sediment management: the case of the Mississippi Delta The case of the Mississippi Delta is one in which the combination of the structural and functional strategies may be required to adapt to high-end scenarios of SLR. The strategy of rising grounds is already being implemented in many wetland areas through controlled diversions to mitigate land loss (Day et al., 2009; Nittrouer et al., 2012; Day et al., 2012). The recently released 2012 Coastal Master Plan proposes river diversions to divert sediment and fresh water from the Mississippi and Atchafalaya rivers into adjacent basins, to reconnect the river to delta wetlands (Falcini et al., 2012). However the strategy of rising dikes is also being implemented and the most However, the strategy of rising dikes is also being implemented, and the most characteristic case is the reinforcement of the protection dikes in New Orleans after hurricane Katrina (Day et al., 2007). With high-end scenarios of SLR and the occurrence of hurricanes, the protection of New Orleans exclusively with dikes will not be feasible.

15 Combining adaptation and mitigation measures in rice fields Rice is the second most important crop worldwide and is the basic food for 50% of the world population, as well as one of the major anthropogenic sources of CH4. Around 65% of the Ebro Delta is occupied by rice fields (ca Ha). It is a widespread crop in many Mediterranean and dasian deltas. Rice fields are the perfect habitat for integrating adaptation and mitigation goals: - The supply of water with nutrients and sediments promote inorganic and organic accretion and carbon sequestration. ti - The change in water management may reduce GHG emissions and increase carbon sequestration as well. 04/12/

16 The Project Life EBRO-ADMICLIM We propose an integrated approach for managing water, sediment and habitats (rice fields and wetlands), with the multiple aim of increasing ground elevation (through inputs of inorganic sediment and organic matter), reducing coastal erosion, increasing carbon sequestration in the soil, reducing emissions of greenhouse gases (GHG), and improving water quality. Put it in another way, the idea is to jointly manage the inputs of inorganic and organic matter (i.e. sediment and plant residues respectively) of the ground, in order to optimize vertical accretion processes (soil formation) and organic matter decomposition (GHG emissions) in rice fields and in constructed wetlands. 04/12/

17 The Project Life EBRO-ADMICLIM The main pilot adaptation actions focus on sediment inputs from the Ebro River into its Delta. The aim is to demonstrate the feasibility of permanently restoring the sediment flow, both from a water treatment plant on the Ebro (Consorci d Aigües de Tarragona, CAT) and from the reservoirs along the lowest stretches of the Ebro. Pilot actions are also proposed for the rice fields and wetlands, to optimize carbon and nutrient sequestration and GHG emissions, and increase the ground elevation. The results will serve to establish guidelines for a program of adaptation ti and mitigation measures (with emphasis on the rice sector) in which it will be essential to design a strategy for voluntary reduction of GHG emissions commanding the support of the rice sector. 04/12/

18 The Project Life EBRO-ADMICLIM B1. Pilot test of injection of sediment from a water treatment plant into the Ebro Delta irrigation network. Assessing the feasibility of reinjecting sediments from the water treatment plant into the Ebro Delta, so that the sludge becomes a resource contributing to climate change adaptation. B2. Pilot test of injecting sediment into the final stretch of the river Ebro. Evaluation of the potential for sediment transport in the current hydrologic conditions of the River Ebro, to determine the feasibility of transferring sediments from the reservoirs. B3. Operational optimization of two constructed wetlands to maximize carbon sequestration, the soil elevation, and the assimilation of nutrients and pollutants. Optimization of these variables by testing different water management schemes. B4. Optimization of GHG emissions and carbon sequestration in the rice fields of the Ebro Delta. Evaluation of emissions and sequestration as a function of agricultural practices and the characterization of terrains. Establishment of the basis for a plan for GHG emissions management. B5. Evaluation of the effects of sediment from a water treatment plant on rice production and GHG emissions. To assess the possible effects of sediment supply from the water treatment plant CAT on rice production. B6. Assessment of areas vulnerable to subsidence and sea-level rise. Determination of the most vulnerable areas of the delta with high spatial resolution. B7. Developing a Climate Action Plan of the Ebro Delta. Integration of adaptation measures and mitigation to develop a coherent scheme of measures that will combine those in the Catalan Strategy for Climate Change Adaptation with those resulting from the pilot actions. 04/12/

19 Partners: The Project Life EBRO-ADMICLIM - Institut de Recerca i Tecnologia Agroalimentàries (IRTA) - Agència Catalana de l Aigua (ACA) - Consorci d Aigües de Tarragona (CAT) - Comunitat de Regants i Sindicat Agrícola de l Ebre (CRSAE) - Institut Cartogràfic i Geològic de Catalunya (ICGC) - Oficina Catalana del Canvi Climàtic (OCCC) - Universitat de Córdoba (UCO) Expected start date: 02/06/2014 Expected end date: 01/06/2018 Total project budget: 2,260,960 Euro EU financial contribution requested: 1,124,341 Euro 04/12/

20 The Projecte RISES-AM- (FP VII) 1. Responses to coastal climate change: Innovative Strategies for high End Scenarios -Adaptation and Mitigation- 2. Objectives: To increase the knowledge on the response of coastal systems to climate variability, through the development of models and risk analysis. To develop and analyze adaptation pathways of the most vulnerable coastal systems at global, regional and local scales, including solutions based on ecological engineering and green infrastrcutures. To identify synergies between adaptation and mitigation options at all scales. In the Ebro Delta de project will model the impacts of relative sea level rise on rice fields and wetlands, with and without additional adaptation measures. 04/12/

21 The Project RISES-AM- 04/12/

22 XX Aniversari CIIRC Gràcies per la vostra atenció! 04/12/