Le partage de la ressource en eau sur la Durance en 2050 : vers une évolution du mode de gestion des grands ouvrages duranciens ?

Congrès SHF: Water Tensions in Europe and in the Mediterranean: water crisis by 2050?, Paris, FRA, 08-/10/2015 - 09/10/2015International audienceUne vision prospective de la gestion de l'eau du bassin de la Durance et des territoires alimentés par ses eaux à l'horizon 2050 a été élaborée, appuyée par une chaine de modèles incluant des représentations du climat, de la ressource naturelle, des demandes en eau et du fonctionnement des grands ouvrages hydrauliques (Serre-Ponçon, Castillon et Sainte-Croix), sous contraintes de respect des débits réservés, de cotes touristiques dans les retenues et de restitution d'eau stockée pour des usages en aval. Cet ensemble, validé en temps présent, a été alimenté par des projections climatiques et paramétré pour intégrer les évolutions du territoire décrites par des scénarios de développement socio-économique avec une hypothèse de conservation des règles de gestion actuelles. Les résultats suggèrent à l'horizon 2050 : une hausse de la température moyenne de l'air impactant l'hydrologie de montagne ; une évolution incertaine des précipitations ; une réduction des stocks de neige et une fonte avancée dans l'année qui induisent une réduction des débits au printemps ; une diminution de la ressource en eau en période estivale ; une diminution de la demande globale en eau à l'échelle du territoire, cette demande étant fortement conditionnée par les scénarios territoriaux élaborés ici ; la satisfaction des demandes en eau en aval des ouvrages considérées comme prioritaires, au détriment de la production d'énergie en hiver (flexibilité moindre en période de pointe) et du maintien de cotes touristiques en été ;une diminution de la production d'énergie due notamment à la réduction des apports en amont des ouvrages hydroélectriques

Oxytocin and Vasopressin Involved in Restraint Water-Immersion Stress Mediated by Oxytocin Receptor and Vasopressin 1b Receptor in Rat Brain

Aims: Vasopressin (AVP) and oxytocin (OT) are considered to be related to gastric functions and the regulation of stress response. The present study was to study the role of vasopressinergic and oxytocinergic neurons during the restraint waterimmersion stress. Methods: Ten male Wistar rats were divided into two groups, control and RWIS for 1h. The brain sections were treated with a dual immunohistochemistry of Fos and oxytocin (OT) or vasopressin (AVP) or OT receptor or AVP 1b receptor (V1bR). Results: (1) Fos-immunoreactive (Fos-IR) neurons dramatically increased in the hypothalamic paraventricular nucleus (PVN), the supraoptic nucleus (SON), the neucleus of solitary tract (NTS) and motor nucleus of the vagus (DMV) in the RWIS rats; (2) OT-immunoreactive (OT-IR) neurons were mainly observed in the medial magnocellular part of the PVN and the dorsal portion of the SON, while AVP-immunoreactive (AVP-IR) neurons mainly distributed in the magnocellular part of the PVN and the ventral portion of the SON. In the RWIS rats, Fos-IR neurons were indentified in 31 % of OT-IR neurons and 40 % of AVP-IR neurons in the PVN, while in the SON it represented 28%, 53 % respectively; (3) V 1bR-IR and OTR-IR neurons occupied all portions of the NTS and DMV. In the RWIS rats, more than 10 % of OTR-IR and V1bR-IR neurons were activated in the DMV, while lower ratio in the NTS. Conclusion: RWIS activates both oxytocinergic and vasopressinergic neurons in the PVN and SON, which may project to th

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

[Departement_IRSTEA]Eaux [TR1_IRSTEA]ARCEAUInternational audienceWater 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

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

International audienceWater 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

Low flows and reservoir management for the Durance River basin (Southern France) in the 2050s

International audienceThe Durance River is one of the major rivers located in the Southern part of France. Water resources are under high pressure due to significant water abstractions for human uses within and out of the natural boundaries of the river basin through an extended open channel network. Water demands are related to irrigation, hydropower, drinking water, industries and more recently water management has included water needs for recreational uses as well as for preserving ecological services. Water is crucial for all these activities and for the socio-economic development of South Eastern France. Both socio-economic development and population evolution will probably modify needs for water supply, irrigation, energy consumption, tourism, industry, etc. In addition the Durance river basin will have to face climate change and its impact on water availability that may question the sustainability of the current rules for water allocation. The research project R2D2-2050 “Risk, water Resources and sustainable Development within the Durance river basin in 2050” aims at assessing future water availability and risks of water shortage in the 2050s by taking into account changes in both climate and water management. R2D2-2050 is partially funded by the French Ministry in charge of Ecology and the Rhône-Mediterranean Water Agency. This multidisciplinary project (2010-2014) involves Irstea, Electricity of France (EDF), the University Pierre et Marie Curie (Paris), LTHE (CNRS), the Society du Canal de Provence (SCP) and the research and consultancy company ACTeon. A set of models have been developed to simulate climate at regional scale (given by 330 projections obtained by applying three downscaling methods), water resources (provided by seven rainfall-runoff models forced by a subset of 330 climate projections), water demand for agriculture and drinking water, for different sub basins of the Durance River basin upstream of Mallemort under present day and under future conditions. A model of water management similar to the tools used by Electricity Of France was calibrated to simulate the behavior of the three reservoirs Serre-Ponçon, Castillon, Sainte-Croix on present-day conditions. This model simulates water releases from reservoir under constraints imposed by rule curves, ecological flows downstream to the dams and water levels in summer for recreational purposes. The results demonstrate the relatively good performance of this simplified model and its ability to represent the influence of reservoir operations on the natural hydrological river flow regime, the decision-making involved in water management and the interactions at regional scale. 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. This presentation will focus on the specific tools developed within the project to simulate water management and water abstractions. The main conclusions related to the risk of water shortage in the 2050s and the level of satisfaction for each water use will be also discussed

Projet R²D² 2050 : Risque, ressource en eau et gestion durable de la Durance en 2050

The Durance River is one of the major rivers located in the Southern part of France. Water resources are under high pressure due to significant abstractions for various water uses (irrigation, hydropower, drinking water, industries, recreation and ecological services) within and out of the river basin. The water management with the Durance River basin will have to face global change that may question the sustainability of the current rules for water allocation. A chain of models was developed to simulate climate at regional scale (given by 3300 projections obtained by applying three downscaling methods), water resources (provided by six rainfall-runoff models forced by a subset of 330 climate projections), water demand for agriculture and water supply for domestic purposes for different sub-basins of the Durance River basin upstream of Mallemort under present-day and future conditions. A model of water management was developed to simulate reservoir operations for the three main dams (Serre-Ponçon, Castillon, Sainte-Croix) on present-day conditions. This model simulates water releases from reservoir under constraints imposed by rule curves, ecological flows downstream to the dams and water levels in summer for recreational purposes. Four territorial socio-economic scenarios were also elaborated with the help of stake holders to project water needs in the 2050s for the areas supplied with water diverted from the Durance River basin. Results suggest: - a projected increase of the average air temperature with consequences on snow accumulation and melt processes; - no significant trends in total precipitation; - a decrease in snowpack, which will lead to reduced flows, especially in the spring season; - a decrease in water resources in summer; - an increase of pressure on water resources; - a decrease in water demand for irrigation as a consequence of the socio economics scenarios; - a decrease in energy produced by the main dams in the Durance River basin in the 2050s mainly due to reduced annual inflows; - a full compliance with water needs for priority uses downstream the reservoir but a lower flexibility for hydropower management during winter peak energy demand.Une vision prospective de la gestion de l’eau du bassin de la Durance et des territoires alimentés par ses eaux à l’horizon 2050 a été élaborée, appuyée par une chaine de modèles. Cette chaine inclut des représentations : - du climat, - de la ressource naturelle, - des demandes en eau pour l’agriculture et l’alimentation en eau potable, et - du fonctionnement des grands ouvrages hydrauliques (barrages de Serre-Ponçon, de Castillon et de Sainte-Croix), sous contraintes de respect des débits réservés, de cotes touristiques dans les retenues et de restitution d’eau stockée pour des usages en aval. Cet ensemble, validé en temps présent, a été alimenté par des projections climatiques et paramétré pour intégrer les évolutions du territoire décrites par des scénarios de développement socio-économique avec une hypothèse de conservation des règles de gestion actuelles. Les résultats des simulations suggèrent à l’horizon 2050 : - une augmentation de la température moyenne de l’air impactant l’hydrologie de montagne,- une évolution incertaine des précipitations, - une diminution des stocks de neige et une fonte avancée dans l’année qui induisent une réduction des débits au printemps, - une diminution de la ressource en eau en période estivale, - une diminution de la demande globale en eau à l’échelle du territoire, cette demande étant fortement conditionnée par les scénarios territoriaux élaborés ici, - la satisfaction des demandes en eau en aval des ouvrages considérées comme prioritaires, au détriment de la production d’énergie en hiver (flexibilité moindre de l’hydro-électricité en période de pointe) et du maintien de cotes touristiques en été, - une diminution de la production d’énergie due notamment à la réduction des apports en amont des ouvrages hydroélectriques

The peptide TRH uncovers the presence of presynaptic 5-HT1A receptors via activation of a second messenger pathway in the rat dorsal vagal complex

It is well recognized that brainstem microinjections of 5-hydroxytryptamine (serotonin, 5-HT) and thyrotropin-releasing hormone (TRH) act synergistically to stimulate gastric function in vivo. Previous in vitro experiments have shown that this synergism does not occur at the level of the dorsal motor nucleus of the vagus (DMV) motoneurone.In order to determine the mechanism of this action, whole cell patch clamp recordings were made from identified gastric-projecting rat DMV neurones to investigate the effects of 5-HT and TRH on GABAergic inhibitory postsynaptic currents (IPSCs) evoked by stimulation of the nucleus of the tractus solitarius (NTS).5-HT (30 μM) decreased IPSC amplitude by 26 ± 2.5 % in approximately 43 % of DMV neurones. In the remaining neurones in which 5-HT had no effect on IPSC amplitude, exposure to TRH (1 μM) uncovered the ability of subsequent applications of 5-HT to decrease IPSC amplitude by 28 ± 3 %. Such TRH-induced 5-HT responses were prevented by the 5-HT1A antagonist NAN-190 (1 μM) and mimicked by the 5-HT1A agonist 8-OH-DPAT (1 μM).Increasing cAMP levels using the phosphodiesterase inhibitor isobutylmethylxanthine (IBMX; 10 μM), the non-hydrolysable cAMP analogue 8-bromo-cAMP (1 mM), or the adenylate cyclase activator forskolin (10 μM), like TRH, uncovered the ability of 5-HT to decrease evoked IPSC amplitude (17 ± 2.2 %, 28.5 ± 5.3 % and 30 ± 4.8 %, respectively), in neurones previously unresponsive to 5-HT. Conversely, the adenylate cyclase inhibitor, dideoxyadenosine (10 μM) and the protein kinase A inhibitor, Rp-cAMP (10 μM), blocked the ability of TRH to uncover the presynaptic inhibitory actions of 5-HT.These results suggest that activation of presynaptic TRH receptors initiates an intracellular signalling cascade that raises the levels of cAMP sufficient to uncover previously silent 5-HT1A receptors on presynaptic nerve terminals within the dorsal vagal complex