Our Common Future Under Climate Change

International Scientific Conference 7-10 JULY 2015 Paris, France

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Wednesday 8 July - 17:30-19:00 UPMC Jussieu - Amphi Astier

2212 (b) - Climate change and freshwater – 2: Shaping the Future

Parallel Session

Lead Convener(s): A. Mishra (UNESCO, Paris, France), H. Lins (President of WMO Commission for Hydrology, Washington, United States of America)

Convener(s): E. Servat (IAHS, Allenvi, IRD, Montpellier, France), N. Dorfliger (Allenvi, BRGM, Orléans, France), C. Cudennec (IAHS, Allenvi, Agrocampus Ouest, Rennes, France)

17:30

Water security: Global challenges, global responses?

F. Berkhout (King's College London, London, United Kingdom)

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Water security: Global challenges, global responses?

F. Berkhout (1)
(1) King's College London, Geography, London, United Kingdom

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Röckstrom et al. (2009) suggest using consumptive water run-off (or blue water use) as a proxy for global freshwater use. Assuming an upper limit of ~12 500–15 000 km3 year-1 of accessible blue water resources, they suggest that consumptive uses above a threshold of 4000–6000 km3 year-1 would represent a significant risk to ecosystems, moisture feedbacks and freshwater/ocean mixing. Given that consumptive use is now at about 2600 km3 year-1 the authors conclude that there appears to be some room for manoeuvre, although there continues to be a trend of rapidly growing consumptive water use at the global scale. An Anthropocene or planetary boundaries framing of global sustainable development problems suggests a global governance of planetary boundaries. But there are questions about whether the planetary (or global) scale is really the appropriate scale at which to govern many of critical global resources and environmental services, including water. Water is typically governed at the level of the river basin and ecosystem. Moreover, while for some global environmental problems, like stratospheric ozone depletion, global governance appears to have been, in large part, successful, there are questions about whether such global coordination can be achieved in other cases. While global governance regimes now exist in many environmental domains, including climate change, achieving an alignment of interests leading to a common understanding of the problem and effective action at the global scale has often proven elusive. Water security emerges at many different and connected scales, from the local to the global. There are important legal, regulatory and voluntary dimensions of global water governance that contribute to water security across these scales. These include norms about rights to water, trade in virtual water, technical and other standards for water use and quality, as well as international transfers of knowledge, technology and finance to support water security. The paper argues that much of the task of governance will need to be focused on fostering transitions in water use, starting at the local level.

17:45

Shaping the future of freshwater: towards a collective effort to enhance our understanding and capacity to model change

H. Savenije (IAHS, Delft Technical University, Delft, Netherlands), A. Montanari (IAHS, Bologna University, Bologna, Italy), C. Cudennec (IAHS, Allenvi, Agrocampus Ouest, Rennes, France)

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Shaping the future of freshwater: towards a collective effort to enhance our understanding and capacity to model change

H. Savenije (1) ; A. Montanari (2) ; C. Cudennec (3)
(1) IAHS, Delft Technical University, Delft, Netherlands; (2) IAHS, Bologna University, Bologna, Italy; (3) IAHS, Allenvi, Agrocampus Ouest, Rennes, France

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A large part of the Earth surface may still be in pristine condition, but humans have already had significant impacts on many hydrological processes relevant to society. Humans have changed the face of the Earth dramatically over time and in doing so introduced substantial changes in the water cycle. Climatic change is one of these impacts, but effects of land use change on: erosion, the character of floods, droughts, and the partitioning and distribution of moisture fluxes are often more strongly noticeable at human scales.

In fact, the limited transferability of water in space and time implies that water withdrawals from natural resources take place where and when water is needed, thereby causing a direct perturbation to all water bodies relevant to society, and therefore to society itself. The current trend of population dynamics and the current status of water systems are such that this impact will not be sustainable in the near future. Therefore mitigation actions are urgently needed, and planning thereof needs to be based on improved interpretations of the impact.

Until recently, hydrologists mainly concentrated on catchments where human perturbation was limited, so as to improve the understanding of pristine hydrology. Nowadays, the urgency to mitigate the global water crisis through improved water management calls for research that attempts to bridge water and social sciences. To reach this target, new science is needed aimed at improved interpretation and modeling of the integrated human and water system. The question is how to build operational models that fully account for the interactions and feedbacks between water resources systems and society. This scientific challenge and the ambition to improve freshwater management in a changing environment together form the pillars of the science initiative "Panta Rhei", promoted by the International Association of Hydrological Sciences. Panta Rhei focuses on three targets, namely: to improve understanding; to enhance predictive capabilities; and to support societal planning. Two years since its inception, Panta Rhei already counts 30 working groups, involving about 300 scientists, who are developing innovative theories and modeling approaches to address the above challenges. In doing so, Panta Rhei is catalyzing a global and collective effort to assist societies to mitigate the global water crisis.

18:00

Prospective approach for assessing change in water resources management for large river basins in France

E. Sauquet (IRSTEA, Lyon, France), Y. Arama (Acteon, Grenoble, France), E. Blanc-Coutagne (SCP, Aix en Provence, France), H. Bouscasse (Acteon, Grenoble, France), F. Branger (IRSTEA, Lyon, France), I. Braud (IRSTEA, Lyon, France), J.-F. Brun (SCP, Aix en Provence, France), A. Ducharne (UPMC, Paris, France), F. Hendrickx (EDF, Chatou, France), B. Hingray (LTHE, Grenoble, France), F. Krowicki (Acteon, Colmar, France), M. Le Lay (EDF, Grenoble, France), F. Malerbe (SCP, Aix en Provence, France), C. Monteil (EDF, Chatou, France), C. Perrin (IRSTEA, Antony, France), R. Samie (EDF, Chatou, France), A. Rossi (Acteon, Colmar, France), P. Strosser (Acteon, Colmar, France), G. Thirel (Irstea, Antony, France), J.-P. Vidal (IRSTEA, Lyon, France)

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Prospective approach for assessing change in water resources management for large river basins in France

E. Sauquet (1) ; Y. Arama (2) ; E. Blanc-Coutagne (3) ; H. Bouscasse (2) ; F. Branger (1) ; I. Braud (1) ; JF. Brun (3) ; A. Ducharne (4) ; F. Hendrickx (5) ; B. Hingray (6) ; F. Krowicki (7) ; M. Le Lay (8) ; F. Malerbe (3) ; C. Monteil (5) ; C. Perrin (9) ; R. Samie (5) ; A. Rossi (7) ; P. Strosser (7) ; G. Thirel (9) ; JP. Vidal (1)
(1) IRSTEA, Lyon, France; (2) Acteon, Grenoble, France; (3) SCP, Aix en Provence, France; (4) UPMC, Paris, France; (5) EDF, Chatou, France; (6) LTHE, Grenoble, France; (7) Acteon, Colmar, France; (8) EDF, Grenoble, France; (9) IRSTEA, Antony, France

Abstract content

Water management planning is influenced by many natural and human factors that interact at basin scale. A multidisciplinary approach is therefore required to both understand and well represent the main characteristics of the water system before analysing its sustainability under global change and suggesting efficient adaptation measures. The complexity of the interactions and thus the challenge in modelling increase with the size of the river basin. This talk presents the main results of the research project R2D2-2050 “Risk, water Resources and sustainable Development within the Durance river basin in 2050” (Sauquet et al., 2014). The Durance River, one of the major rivers located in the Southern part of the French Alps, supplies water for competing human uses (irrigation, hydropower, drinking water, industries and more recently tourism and ecological services) within and out of the drainage area through an extended open channel network. The project R2D2-2050 aimed to assess whether the current water management - especially operating rules for the three main reservoirs - would need changing under future conditions taking into account evolutions in both climate and socio-economy.A multi-model approach was carried out to simulate regional climate, water resources, irrigation needs, water supply for domestic purposes, water transfers and reservoir operations. A model of water management similar to the operational tool used by the French hydropower producer EDF was also developed to simulate water released from the reservoirs on present-day conditions under constraints imposed by ecological flows and water levels in summer for recreational purposes. Four territorial socio-economic scenarios have been also elaborated with the help of stake holders to project water needs in the 2050s for the area supplied with water from the Durance River basin.

Results suggest:

  • an increase in pressure on diminished water resources,
  • a decrease in energy produced by the main dams mainly due to reduced annual inflows,
  • a decrease in biological richness for intermittent rivers,
  • a full compliance with water needs for priority uses downstream from the reservoir but less flexibility for hydropower management during winter peak energy demand if current water management rules are unchanged,
  • more frequent restrictions on water abstraction reducing the demand to be met for sub-basins with no reservoir,
  • socio economic scenarios as the most important source of uncertainty influencing the sustainability of the present-day allocation rules.

Those conclusions will be compared with previous findings from similar impact studies on other large French river basins (Seine (Habets et al., 2013); Garonne (Hendrickx and Sauquet, 2013)).

Habets F., Boé J., Déqué M., Ducharne A., Gascoin S., Hachour A., Martin E., Pagé C., Sauquet E., Terray L., Thiéry D., Oudin L. & Viennot P. (2013). Impact of climate change on surface water and groundwater of two basins in Northern France: analysis of the uncertainties associated with climate and hydrological models, emission scenarios and downscaling methods. Climatic Change, vol. 21, n° 4, p. 771-785

Hendrickx, F. and Sauquet, E., 2013. Impact of warming climate on water management for the Ariège River basin (France). Hydrological Sciences Journal, 58(4), 1–17.

Sauquet, E. et al., 2014. Projet R²D² 2050, Risque, Ressource en eau et gestion Durable de la Durance en 2050. Rapport de fin de contrat, Programme GICC, Ministère de l’Ecologie, du Développement durable et de l’Energie, Novembre 2014, 243 p.

18:15

Panel discussion:

A. Mishra (UNESCO, Paris, France), H. Lins (President of WMO Commission for Hydrology, Washington, United States of America)

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Panel discussion:
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A citizen science approach to managing freshwater resources in the tropical Andes

W. Buytaert (Imperial College London, London, United Kingdom), B. Ochoa-Tocachi, (CONDESAN, Quito, Ecuador), Z. Zulkafli, (Imperial College London, London, United Kingdom), B. De Bievre (CONDESAN, Lima, Peru), M. Saravia Lopez De Castilla (CONDESAN, Lima, Peru)

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A citizen science approach to managing freshwater resources in the tropical Andes

W. Buytaert (1) ; B. Ochoa-Tocachi, (2) ; Z. Zulkafli, (1) ; B. De Bievre (3) ; M. Saravia Lopez De Castilla (3)
(1) Imperial College London, Civil and Environmental Engineering, London, United Kingdom; (2) CONDESAN, Quito, Ecuador; (3) CONDESAN, Lima, Peru

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The tropical Andes are a hotspot of environmental change. The combination of global climate change, local land-use change, demographic growth, and increasing water demand is putting extreme pressures on water resources. This is of particular concern to rural upland communities. They are facing a double challenge of maintaining their own livelihoods with dwindling natural resources, and at the same time supporting downstream ecosystem services such as a well buffered stream flow and good water quality.

This challenge is complicated further by the acute lack of data on the hydrological functioning of Andean catchments. The factors that control their hydrological response are extremely variable in space and time, including meteorological forcing, land cover types, soil properties and geology. This makes it very difficult to predict accurately the impact of human activities such as land use, and watershed investments. Such predictions are essential for policy-making and sustainable ecosystem management.

In order to tackle the issue of hydrological data scarcity in the tropical Andes, we set up a citizen science initiative, implementing a network of hydrological monitoring of upland catchments in a pairwise fashion. Using a trading-space-for-time approach, the initiative aims to use these data to improve predictions about the impact of land-use changes and other ecosystem management practices on the hydrological response. Currently, over 25 catchments are being monitored for precipitation and stream flow in 9 sites located in Venezuela, Ecuador, Peru, and Bolivia. The sites are supported by local stakeholders and communities in a participatory approach that otherwise would be impractical or prohibitively expensive.

Because of the technical challenges of monitoring hydrological variables in remote mountain areas, we set up a web-based infrastructure to support local technicians and stakeholders. Additionally, using open data standards such as those of the Open Geospatial Consortium, the data can be pooled efficiently for regional-scale analysis, as well as processed and visualized efficiently. Lastly, the datasets can be coupled to web-based hydrological models using rich and interactive interfaces. Such setups, which we refer to as “environmental virtual observatories”, can support water and land users at different scales of decision-making, from community level to national governance entities, and at different levels of technical and scientific skills.

In our presentation, we will report on the effort of setting up a citizen science approach to monitoring freshwater resources in the tropical Andes, and how this can be used to support local management efforts. We will discuss our successes, as well as the remaining challenges in the technological, hydrological, and social science domains.

Science-policy interface to foster scientific development and uptake by policy makers for the purpose of water management in the context of climate change and climate change adaptation strategies development

F. Martini (Onema, Vincennes, France)

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Science-policy interface to foster scientific development and uptake by policy makers for the purpose of water management in the context of climate change and climate change adaptation strategies development

F. Martini (1)
(1) Onema, Vincennes, France

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Water resources challenges exacerbated by global change including climate variability can affect water security and human well-being. To globally face this situation, there is a need to develop evidence-based policy incorporating accurate information related to predicted global changes.

But water and climate change research outputs are insufficiently reaching water managers today. And there’s a lack of places where water managers can express the scientific information they need to develop their adaptation strategies.

A science-policy interface (SPI) answers this challenge by enhancing science-based policy development and fostering dialogue between researchers and water managers. It first facilitates the expression of policy requirements of scientific knowledge for specific management decisions, and a common understanding of these needs. It identifies existing scientific knowledge fulfilling policy needs and influences development of research agendas to match future policy needs. It finally allows a mutual understanding and long-lasting dialogue between scientists and policy makers.

Three science-policy interface experiences studied at international, European and national levels led to identify some recommendations to set a sustainable science-policy interface helping to face the challenges of water and climate change.

The 6th World water forum recommended initiating an international networking platform for researchers and water managers in order to facilitate communications in relation to the IPCC and other UN conventions. The objective of such a water SPI is to provide relevant scientific inputs to help governments and water managers develop effective decisions and climate change adaptation strategies, considering the uncertainty related to the impact of climate change on water resources. A mapping of existing SPI mechanisms over the world initiated this investigation.

From 2010 to 2012 a science-policy interface for the water framework directive (WFD) has been operated by the European commission and France. This SPI intended to support WFD implementation by helping provide and if needed produce adequate scientific information.

With a view to improving the uptake of science by policy makers involved in water management decisions in the context of climate change, and conversely the comprehension by scientists of the needs of policy makers, Onema organized on 3 February 2015 a seminar between scientists and policy makers. This event allowed them to share their knowledge and views on scientific needs, and raise recommendations on science-policy dialogue enhancement.

Those three experiences led to consolidate some main principles to set and maintain a science-policy interface which allows a better evidence-based water policy development under climate change.

Establish a sustainable Community of practices (CoP). The CoP is a consistent group of stakeholders of the water sector: scientists, water managers, knowledge brokers, politicians, journalists, civil society, ensuring a multidisciplinary approach. It should engage stakeholders from all the scales of the water management (and around the world). It ensures the operating of the SPI.

Appoint Knowledge Brokers and form them. They are skilled experts dedicated, trained, and resourced to engage in the SPI. They assist policy makers in formulating scientific and technical questions, enhance the scientific knowledge transfer to the policy makers and contribute to keep research aligned with policy needs.

Improve Communication and Tools. Communication may be encouraged and improved at all levels through the creation of a platform in which the CoP can share information and network. Recent research findings and request for collaborators with particular expertise for future research projects can be shared there. Policy makers can there access scientific information digested into policy briefs and other publications, seek experts’ scientific opinion, and communicate their research needs to scientists.

The importance of protecting and restore freshwater ecosystems for sustainable development and building resilience to climate change

K. Lexen (Stockholm International Water Institue, Stockholm, Sweden), S. Widforss (Stockholm International Water Institue, Stockholm, Sweden)

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The importance of protecting and restore freshwater ecosystems for sustainable development and building resilience to climate change

S. Widforss (1) ; K. Lexen (2)
(1) Stockholm International Water Institue, International Processes, Stockholm, Sweden; (2) Stockholm International Water Institue, World water week & international processes, Stockholm, Sweden

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According to OECD (2012), the global demand for freshwater is projected to increase by 55 % between 2000 and 2050. Freshwater ecosystems such as wetlands, lakes and peatlands are the most essential of ecosystem services providing for food security, income, health and resilience to climate change induced impacts. Safely managed water resources are necessary for human wellbeing, for protecting communities from climate induced vulnerability and risk. (Millennium Ecosystem Assessment 2005) Stress on already exposed water recourses has implications on local communities relying on the sources for their human security and livelihood; it will impair the ability to overcome inequalities, and enhance   economic development (UN Water 2014). Women are at a higher risk of being negatively affected by hydro-climatic disasters, and to the exposure of water- and sanitation related diseases. Freshwater interlinks sustainable development strategies with effective mitigation action. Wisely managed water strengthens climate adaptation capacities and protects livelihoods. Freshwater ecosystems harness the potential for reduced climate vulnerability, while being vital for resilient, prosperous communities, and this should be acknowledged in global policies. Further, bridging the gap between policy and practice; facilitating the integration and application of local expertise from indigenous communities, is necessary in order to build relevant capacity.

“Water crisis and tensions in Europe and in the Mediterranean by 2050: future scenarios?”

S. Fernandez (IRSTEA, Strasbourg, France), M. Lang (IRSTEA - Lyon, Lyon, France), M.-A. Martin (Académie de l'Eau, Paris, France), J. Verdier (AFEID, Montpellier, France), P.-L. Viollet (SHF, Paris, France)

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“Water crisis and tensions in Europe and in the Mediterranean by 2050: future scenarios?”

S. Fernandez (1) ; M. Lang (2) ; MA. Martin (3) ; J. Verdier (4) ; PL. Viollet (5)
(1) IRSTEA, Umr geste, Strasbourg, France; (2) IRSTEA - Lyon, Research unit on hydraulics and hydrology, Lyon, France; (3) Académie de l'Eau, Water management, Paris, France; (4) AFEID, Montpellier, France; (5) SHF, Paris, France

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All around the world, water resources management is facing numerous challenges. The predicted effects of greenhouse gas emissions are of particular concern with regard to future droughts, which frequency and intensity are expected to increase. Despite the many uncertainties reflected in various future studies conducted in France, a general trend of decline emerges in the long term (2050-2070) with a 10 to 40 % decrease of the annual average river flows. Due to the decrease in snowy surfaces, rivers could also evolve from a nival (snowmelt dominated) regime to a pluvial (rainfall) regime, with lower flows during the summer – when crop evapotranspiration is at its maximum. Studies carried out on aquifers, suggest, under a business-as-usual scenario, an acceleration and intensification of the level of exploitation or of the degradation of the quality of many of them. Challenges and risks are particularly high in the Mediterranean countries, with a tendency towards an increased concentration of their population along coasts or within deltas, having direct and significant implications for drinking water supply and sanitation.

Foresight studies on water - related issues. The issue of scale is usually not discussed as such when conducting foresight studies. The watershed is certainly a relevant unit for surface hydrology. It does not, however, necessarily allow grasping groundwater, nor the territorial basis upon which public action is deployed. Greater emphasis should also be given to other scales such as water supply and water demands. On one hand, quantification is important in order to ensure the consistency of a given scenario, but it must be done a posteriori and not a priori. On the other hand, possible disruptions are difficult to model. Their probability of occurrence can certainly be quite well modeled, as long as a wide range of temporal uncertainty is acknowledged. What happens after any type of disruption is, instead, often qualitatively and quantitatively unpredictable.

Issues related to the status of global change. Climate change is usually represented as a “driving force” of the system at stake, that legitimizes foresight debates, since it should lead to a decrease of water resources (on an annual or seasonal average),that could be very intense locally, and to a greater variability of the resource in space and time. While the water and climate nexus was brought to the international political agenda, the concept of adaptation also emerged, a concept to be differentiated from mitigation. Water issues are also to be framed in terms of adaptation, while having in mind that mitigation measures can significantly reduce adaptation costs.

Future issues. In Europe and in the Mediterranean basin, major issues are related to future tensions over water resources management and to likely induced disruptions. Possible answers to this should take into account the relations between climate change and the evolution of water uses, at an adequate time horizon (2050); it should also integrate hydrological and climate studies as well as social sciences approaches or results. Such is the aim of the international conference "Water Tensions in Europe and in the Mediterranean basin: water crisis by 2050?" organized by SHF, AFEID, the Water Academy and UISF, to be held at Paris (7-9 October 2015). Three cardinal themes have been identified: 1/Analysis of past and present “crises” and tensions on water resources. How, by whom and when, these past events have been classified as "crises" of "tensions"...? How were they governed, evaluated, explained? How may these analyses help in managing the future? 2/Forecast of the evolution of surface water and groundwater regime by 2050, and consequences associated in terms of water scarcity and water quality deterioration. The issue of uncertainty linked to the identified spatial scales shall be studied as well. 3/Methodological issues for prospective studies. How to build relevant analysis scales in prospective studies, how to relate them to water flows and territories? How to recognize and clarify uncertainties related to prospective studies and how to make more explicit the social and political dimensions that are inherent to prospective analysis? How to tackle water crises and their consequences? What kind of ruptures are to be considered? What can be expected from “new” technologies?