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El estudio de los niveles y composición del material particulado atmosférico (PM) medido simultáneamente en diferentes ambientes a escala regional se llevó a cabo en la cuenca del Mediterráneo Occidental con el fin de entender las fuentes y patrones de transformación y transporte de aerosoles en esta zona. Para esto, la medida de niveles y caracterización química de PM10, PM2.5 y PM1 se llevó a cabo en tres estaciones de monitoreo: Montsec (MSC, fondo continental, 1570 msnm), Montseny (MSY, fondo regional, 720 msnm) y Barcelona (BCN, fondo urbano, 68 msnm). Además, se midieron niveles de número de partículas (N) y carbono negro (BC) en BCN. Durante el invierno, la frecuente estabilidad atmosférica induce el estancamiento de masas de aire produciendo importantes episodios de contaminación en BCN. Sin embargo, MSY y, más frecuentemente MSC, quedan aislados de la contaminación regional. En determinados escenarios, el desarrollo de la capa límite y las brisas resultan en el transporte de masas de aire contaminadas a zonas rurales, aumentando notablemente los niveles de PM en función de la altitud y la distancia a las zonas fuente. Durante el verano, la circulación de brisas favorece la dispersión, mezcla y envejecimiento de contaminantes a escala regional y la reducción de las diferencias entre BCN, MSY y MSC. Se midieron niveles similares de algunos componentes (materia orgánica, sulfato) a escala regional. Los niveles de materia mineral aumentan en verano por una resuspensión favorecida y una mayor frecuencia de intrusiones africanas, más significativamente en el MSC, dado su impacto en altura. La mayor contribución al PM10 en BCN se debe principalmente al tráfico (50% del PM10), resultante de las emisiones del tráfico primarias, nitrato y aerosoles secundarios envejecidos. La materia mineral se origina por resuspensión del polvo de carretera por vehículos pero también resuspensión por viento y obras. La contribución regional en BCN (25%) es principalmente materia mineral, nitrato y sulfato amónico. La variabilidad horaria de los diferentes parámetros de medida de aerosoles en BCN (N, BC, PM10, PM2.5 y PM1) está muy marcada por emisiones de tráfico y meteorología (especialmente brisas). Sin embargo, algunos parámetros no se rigen solamente por emisiones directas del tráfico, como PM2.5-10 (resuspensión) y N (emisiones de partículas ultrafinas y procesos de nucleación fotoquímica). La influencia de las emisiones del tráfico en los niveles de partículas finas en BCN se refleja en los niveles anuales de PM1, que aumentan de 2003 a 2007 relacionados con un aumento progresivo del tráfico y la flota diesel en BCN. Sin embargo se observó una tendencia decreciente en las fracciones gruesas en BCN y MSY, que se atribuye a la meteorología y a cambios en emisiones industriales. El estudio simultáneo de diferentes parámetros ha mostrado que el control de PM1 (modos de nucleación y acumulación) y/o BC (procesos de combustión), y PM10, (combustión y aerosoles generados mecánicamente) puede ser una estrategia mejor que la combinación de PM2.5 y PM10 como estándares de medida de calidad del aire. La medida en paralelo de aerosoles en fondos urbano, regional y continental ha sido una estrategia útil para entender la fenomenología de aerosoles en la cuenca del Mediterráneo Occidental. Las emisiones urbanas e industriales tienen un impacto considerable en los niveles y composición de PM en zonas rurales situadas a diferentes alturas, tanto en verano, con una importante recirculación y mezcla de masas de aire a escala regional, como en invierno, con transporte de contaminantes activado por brisas. El gran impacto de la contaminación urbana a escala regional demuestra la importancia de aplicar estrategias de reducción de emisiones de tráfico urbano, a fin de mejorar la calidad del aire no sólo a nivel local, sino también a escala regional. / A detailed study of atmospheric particulate matter (PM) levels and composition measured simultaneously in different environments at a regional scale was performed in the Western Mediterranean Basin in order to understand the sources, transformation and transport of tropospheric aerosols in this area. In this direction, the monitoring of PM10, PM2.5 and PM1 levels and chemical characterization was carried out at three monitoring stations: Montsec (MSC, continental background, 1570 m.a.s.l.), Montseny (MSY, regional background, 720 m.a.s.l.) and Barcelona (BCN, urban background, 68 m.a.s.l.). In addition, number concentration (N) and black carbon (BC) levels were monitored at BCN. During winter, the frequent anticyclonic atmospheric stability induces the stagnation of air masses that produce important pollution episodes at BCN. However, atmospheric decoupling leaves MSY and, more frequently MSC, isolated from regional pollution during several days. In specific scenarios, the growth of the boundary layer and development of mountain breezes, activated by solar radiation, result in the transport of polluted air masses accumulated in the valley to the rural sites, increasing markedly PM levels at a different rate depending on the altitude and distance to the source areas. During summer, intense breeze circulations and atmospheric mixing favour the dispersion, recirculation and ageing of pollutants at a regional scale, reducing the differences between the urban and the rural sites. Similar levels of some components (organic matter or sulphate) were measured at a regional scale. Mineral matter levels increase during the summer, because of a favoured dust resuspension and higher frequency of African dust outbreaks, more significantly at MSC given the impact of African dust at higher altitudes. The major contribution to PM10 in BCN was mainly related to road traffic (50% of PM10), resulting from primary traffic emissions, secondary nitrate and aged secondary aerosols. Anthropogenic dust may originate from road dust resuspension by vehicles, but also wind resuspension and construction/demolition works. The regional contribution at the urban site (25%) was mainly mineral dust, ammonium sulphate and nitrate. The hourly variability of aerosol measurement parameters (N, BC, PM10, PM2.5 and PM1) at BCN is very influenced by road traffic emissions and meteorology (especially breezes). However, some parameters are not only governed by traffic exhaust emissions, as PM2.5-10 (dust resuspension processes) and N (direct ultrafine particle emissions but also photochemical nucleation processes). The influence of road traffic emissions on the levels of fine PM at BCN is reflected in PM1 mean annual levels, showing an increasing trend from 2003 to 2007 and correlation with the progressive rise in road traffic flow and diesel fleet in BCN. However a decreasing trend was observed for the coarser fractions at BCN and MSY, attributed to meteorology and changes in industrial emissions. The simultaneous study of different parameters showed that the monitoring of PM1 (nucleation and accumulation modes) and/or BC (combustion processes), and PM10 (combustion and mechanically-generated aerosols) may be a better strategy than the combination of PM2.5 and PM10 measurements as air quality standards. The parallel monitoring of aerosols at urban, regional and continental backgrounds was a useful strategy in order to understand the phenomenology of aerosols in the WMB. Urban and industrial emissions have a considerable impact in PM levels and composition in rural areas at different altitudes, both in summer, with important atmospheric recirculation and mixing of air masses at a regional scale, and winter, with breeze-activated transport of stagnated urban pollutants. The high contribution of urban emissions and the transport of air masses at a regional scale demonstrate the importance of applying emission abatement strategies for urban road traffic, in order to improve air quality not only at a local, but also at a regional scale.

Formal models, those which explicitly specify the postulates on which they are based, the development of their 'predictions' from those postulates, and the boundary conditions under which they apply, have the potential to be useful tools in archaeological inference and explanation. Detailed examination of one such model, the mathematical model commonly referred to as the diet breadth or prey choice model, shows that its archaeological application is severely complicated by two factors that are difficult or impossible to specify for prehistoric cases: 1) limits on the amount of meat consumable by a food-sharing group before spoilage or loss to scavengers and 2) hunting failure rates. The former introduce significant uncertainties into the food yield or energetic return term of resource rankings, while the latter affect both resource rankings and the resouce encounter rates leading to prey inclusion or exclusion from the diet. Together, these factors make rigorous diet breadth / prey choice model-based inferences from ungulate archaeofaunas impractical, especially in Paleolithic cases. Following success in recent years in making diet breadth model-based inferences about Paleolithic demography from small game analyses that involved computer simulation modeling of prey species' resilience to hunting pressure, the development and employment of a similar model applied to ungulate species reveals that, in general, the differences in the abilty of populations of different ungulate species to sustain harvest rates are not sufficient to allow the relative representation of ungulate remains in archaeological sites to be a viable basis for human demographic inferences. However, in cases where ungulate remains allow the determination of both prey age structure and sex ratio, it is possible to distinguish low exploitation rates, high exploitation rates, and overhunting. In some cases, the sex ratio data may also alter relative hunting resilience levels in such a way that it may be possible to infer that one species was capable of supporting a larger human population than another.

Podeu escriure el text directament o arrossegar-lo des d'un altre documentL'objectiu d'aquesta tesi és contribuir a l'ús dels peixos continentals com a indicadors de l'estat ecològic a la conca Mediterrània. En el primer treball es va detectar que encara que tots els índex biològics estaven correlacionats significativament, els peixos integren i expressen els estressos de manera i a una escala diferents, aportant una informació complementària als altres índexs. Al segon article es van estudiar els cabals de sis conques catalanes. S'ha mostrat que els règims hídrics estan alterats amb una tendència a la disminució del cabal i del nivell dels aqüífers. S'ha detectat quatre mètriques de peixos que es troben significativament afectades en zones més castigades per manca d'aigua degut a l'activitat humana. Es discuteix la necessitat de conèixer en profunditat el règim hídric de cada conca abans d'utilitzar els índex biològics. Al tercer article es va detectar que la composició d'espècies capturades va variar significativament al llarg del buidat amb un augment de l'alburn (A. alburnus) a les aigües pelàgiques durant els dies de pitjor qualitat de l'aigua, confirmant que l'alburn és més tolerant a la mala qualitat de l'aigua que la madrilleta vera (R. rutilus) i suggereix el seu potencial com a bioindicador. La condició d'aquestes dues espècies va canviar significativament al llarg del buidat de manera molt estreta amb la qualitat de l'aigua. Al quart capítol es va estudiar la biologia dels peixos d'un embassament altament contaminat (Flix). El percentatge de DELT anomalies i la presència de paràsits externs era major en la zona impactada que als punts de control i els valors més alts de pes eviscerat i pes del fetge estaven als punts de control. Les respostes van ser diferents per cada espècie i la carpa va ser la que va mostrar més clarament els impactes. / Podeu escriure el text directament o arrossegar-lo des d'un altre documentThe aim of this thesis is to contribute to the use of freshwater fish as ecological indicators in the Mediterranean basin. In the first article we found that although most biological indices were correlated, fish reflected different ecological aspects due to their particular features. In the second article the stream flow regimes of six Mediterranean basins were studied. A decrease of streamflow and aquifer levels was detected, despite no observed decrease of rainfall precipitation. Of the thirty metrics tested to detect sites impacted by water abstraction, we detected four significant fish metrics. Furthermore, the role of biotic indices when the river is artificially dry is discussed. In the third article we found that species composition in the pelagic zone varied significantly during the drawdown with higher proportion of bleak (A. alburnus) during the days of worst water quality, confirming that bleak is more tolerant than roach (R. rutilus) to poor water quality. The weight-length relationship of roach and bleak also varied significantly during the drawdown with close relationship between water quality and fish condition. In the fourth article the condition and fecundity of freshwater fishes were assessed in a highly polluted reservoir (Flix reservoir). We have shown significant increases of DELT anomalies and ectoparasite prevalences and decreases in condition and fecundity of several freshwater fish at the impacted area. The responses to the pollutants were species-specific and common carp was the species that showed more markedly the effects.

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Les océans couvrant plus de 70 % de la surface de la Terre, les aérosols marins sont une des composantes les plus importantes en terme de concentration atmosphérique. De part leur large gamme de taille, ils interagissent à la fois dans les courtes et grandes longueurs d’onde et impactent ainsi le bilan radiatif à la surface et au sommet de l’atmosphère. Cependant, l’amplitude de cet impact climatique est encore soumise à de nombreuses incertitudes. Actuellement en modélisation, il existe très peu de cas d’études centrés sur les aérosols marins au niveau régional, la plupart étant réalisés au niveau global. Dans ce cadre et afin d’améliorer la connaissance des propriétés des aérosols marins et leurs effets radiatifs dans le bassin méditerranéen, le projet ChArMEx qui s’est déroulé pendant les étés 2013 et 2014, a permis la mise en place de plusieurs sites de mesures, notamment a Ersa (Cap Corse), ainsi que des observations aéroportées. Les observations réalisées à Ersa ont permis de repérer dans une première étude une période (22-26 juin) influencée majoritairement par les aérosols marins lors de l’été 2013 et de caractériser leurs propriétés physico-chimique, optiques et radiatives. De plus, l’impact de ces aérosols marins a pu être comparé à l’influence d’autres types d’aérosols présents dans le bassin méditerranéen (poussières désertiques, aérosols anthropiques et issus de feux de biomasse) également observés pendant la campagne de mesure. L’étude combinée de la composition chimique des aérosols marins et des rétro-trajectoires issues du modèle FLEXPART a permis également de mettre en évidence les multiples origines des aérosols marins, avec des émissions locales et des aérosols âgés associés à du transport longue distance. En se basant sur cette analyse, le modèle MesoNH a été utilisé pour étudier dans un premier temps les émissions, le transport et la concentration atmosphèrique des aérosols marins à l’échelle régionale, sur cette période d'étude. Pour cela, un nouveau schéma d’émission basé sur une paramétrisation récente (Ovadnevaite et al., 2014) a été implémenté dans le modèle. Celle-ci dépend, en plus de la vitesse du vent à la surface, de l’ etat de la mer (représenté par la hauteur des vagues, la température de surface de l’eau ainsi que la salinité). Une première simulation tri-dimensionnelle comprenant trois domaines imbriqués a donc été réalisée sur un domaine méditerranéen du 12 au 27 juin 2013. Les observations réalisées pendant la campagne de mesure ChArMEx-ADRIMED ont permis d’évaluer la capacité du modèle à simuler la concentration en masse et en nombre des aérosols marins ainsi que leur distribution granulométrique. Un deuxième cas d’étude, se déroulant pendant un cas de mistral/tramontane dans le golfe du Lion en juillet 2014, a également été simulé afin d’évaluer dans un second temps les effets radiatifs directs à la surface et au sommet de l’atmosphère (dans les courtes et grandes longueurs d’ondes). Cette simulation est supportée par des observations aéroportées réalisées dans le cadre de la campagne SAFMED+ ainsi que par des observations satellitaires et de télédétection (réseau AERONET). Ce travail indique également un forçage radiatif direct négatif des aérosols marins à la surface, qui est compensé, pour une très faible part, par le forçage radiatif positif exercé dans les grandes longueurs d’ondes. / As the oceans cover more than 70 % of the surface area of the Earth, marine aerosols compose one the most important aerosol types in term of atmospheric burden. As their size distribution comprises submicron and supermicron ranges, marine aerosol interacts with both shortwave and longwave radiation, leading to a radiative impact at the surface, within the atmosphere, and at the top of the atmosphere. However, the magnitude of its climatic impact is still subject to many uncertainties. Most model studies of marine aerosol emissions and their radiative impacts have focused on the global scale rather than the regional scale. In this context and in order to improve the knowledge of aerosol properties in the Mediterranean, and in particular, their impact on regional climate, the ChArMEx-ADRIMED field campaign took place in the Western Mediterranean Basin during the summer 2013. Several ground-based stations were operated throughout the Mediterranean Basin, including a station in Ersa (Corsica). During the ChArMEx-ADRIMED observation period, a major influence of marine aerosols was detected (22-26 June), allowing the characterization of their physical, chemical, optical and radiative properties. Moreover, the radiative impact of marine aerosols was compared to the influence of other types of aerosols usually present in the Mediterranean Basin (desert dust, anthropogenic and biomass burning aerosols) also observed during the field campaign. The combined study of the chemical composition of marine aerosols and backward trajectories using the FLEXPART model was used to characterize aging and origins of marine aerosols observed at the Ersa Station. For this work, the regional scale MesoNH model has been modified to study the radiative effect of marine aerosols on the Mediterranean Basin using a new marine aerosol emission scheme based on a recent parameterization (Ovadnevaite et al., 2014). This parameterization depends not only on the wind speed but also on the sea state (represented by wave height, sea surface temperature and the surface water salinity). A three-dimensional simulation including three nested domains was then conducted on a Mediterranean domain from 12 to 27 June 2013. The observations made during the ChArMEx-ADRIMED field campaign were used to evaluate this parameterization, via comparisons of the modeled and measured mass and number concentration of marine aerosols, as well as their size distribution. Another case study was conducted to assess the shortwave and longwave direct radiative effect, at the surface and top of the atmosphere, of marine aerosol during a period of strong winds (> 20 m s-1; Mistral) in the Golf of Lion (Western Mediterranean Basin). This simulation was conducted in conjunction with airborne observations (during the SAFMED+ field campaign), satellite and remote sensing (AERONET network) observations. Furthermore, this work indicate a negative direct radiative effect at the surface, only partly counterbalanced by a positive forcing in the longwave radiation.

This study is focused on the identification of the sources and processes affecting levels and composition of PM10 and PM2.5 from air quality monitoring networks in Eastern Spain. This is a multidisciplinary study. Time series of TSP and PM10 recorded from 1996 to 2000 are interpreted to assess the role of local, regional and distant sources in PM levels in this region. To this is end, the influence of the meteorology on PM levels recorded at nineteen rural, urban and industrial monitoring stations is studied by means of synoptic charts, back-trajectories and local meteorological variables. The impact of African dust transport on PM levels is investigated by means of simulations in the SKIRON forecast system and by TOMS satellite observations. Moreover, a chemical characterisation of PM10, PM2.5 and TSP size segregated fractions and a daily PM10 and PM2.5 source apportionment by two receptor modelling techniques are performed. For this purpose, 24-hour samples of PM10 were collected for 16, 12 and 5 months at rural, urban and industrial sites, respectively. PM2.5 was sampled at the urban site simultaneously with PM10. The results showed that day-to-day variations in PM levels are highly influenced by the meteorology. From March to October, PM levels at rural, urban and industrial sites vary as a function of the concatenation of Atlantic air mass advections (Atlantic episodes with low PM levels) and regional circulations (Regional events with high PM and O3 levels) which induce the PM transport from urban/industrial to rural sites and the ageing of polluted air masses in the Western Mediterranean. From November to February low PM levels are recorded at rural sites, and variations in PM levels at urban/industrial sites are governed by the successive occurrence of Atlantic episodes and Local urban/industrial pollution events (with high PM, NOx and CO levels). The African dust events mainly occur from January to October and induce very high PM levels in all sites. As a result of the frequency and intensity of the Regional episodes, PM levels at rural sites undergo a seasonal evolution with a summer maximum. The difference between PM levels at urban and rural sites presents an autumn-winter maximum owing to the occurrence of intensive Local urban pollution events. The meteorological context in which the aforementioned episodes occur is discussed, with special emphasis on the synoptic scenarios giving rise to the African dust outbreaks in the different seasons. Levels of PM components at the different study sites were compared. The seasonal evolution and the grain size distribution of these components was studied and the form of occurrence was determined. The chemical characterisation shows that high levels of natural mineral dust components (e.g. Al, Fe, Mg, Ti, Sr, Ca) are simultaneously recorded in PM10 and PM2.5 at all sites during African episodes. Other interesting findings are: 1) a marked seasonal evolution of nitrate levels and grain size distribution due to the occurrence of ammonium-nitrate in autumn-winter, 2) an excess of Na with respect to the Na/Cl marine ratio in summer owing to reactions of acids with sea salt, and 3) high background levels of ammonium-sulphate in summer. Moreover, the levels of elemental, organic and mineral carbon were determined. At the rural site, the PM10 annual mean reaches 22µg/m3, the main contributions being secondary particles from industrial emissions (27% of PM10), vehicle exhausts (14-23%), natural mineral dust (23%) and sea spray (5-9%). At the urban kerbside station, the PM10 annual mean reaches 49µg/m3, the main contributions being vehicle exhausts (35-45% of PM10), secondary particles from industrial emissions (24-31%), natural + road dust (25%) and sea spray (4-6%). At the urban kerbside station, the PM2.5 annual mean reaches 34µg/m3, the main contributions being vehicle exhausts (41-53% of PM2.5), secondary particles from industrial emissions (29-35%) and mineral dust (9-11%). These results have important implications for the implementation of the PM10 EU standards. The natural load in ambient PM10 levels in Eastern Spain accounts for 30-40% of the 2010 EU annual PM10 limit value (20µg/m3). In this region it will not be easy to meet this limit value given that the annual PM10 levels are in the range 17-20µg/m3 at rural, 30-45µg/m3 at urban and 45-60µg/m3 at industrial sites. The high background levels of PM10 in this region are favoured by the specific orographic and meteorological context of the Mediterranean and by the high load of mineral dust caused by the soil re-suspension and the frequent occurrence of African dust events. At rural sites, 2-5 exceedances of the EU daily PM10 limit value (50µg/m3) are recorded every year during African dust outbreaks. On average, 15 African induced and 40-80 non-African induced exceedances of the EU daily PM10 limit value are recorded every year at the urban kerbside stations. The parameter selected for PM monitoring is a key factor. Most of the PM species resulting from combustion and vehicle exhaust emissions have a fine size distribution (<2.5µm), with exception of nitrate in summer, whereas sea spray and mineral dust present a coarse size distribution. The interference of African dust in the PM monitoring is significantly reduced when PM2.5 instead of PM10 is monitored. Natural mineral dust concentrations during African episodes are in the ranges 20-30µg/m3 in PM10 and 10-15µg/m3 in PM2.5. However, PM2.5 is not a suitable parameter for PM monitoring in all environments. The selection of PM10 or PM2.5 should be conditioned by the type of anthropogenic activity. At urban sites, PM2.5 contains mainly vehicle exhaust products, whereas the road traffic dust principally occurs in the 2.5-10µm fraction. PM2.5 is not a suitable parameter for monitoring some industrial activities (e.g. ceramics, cement production or mining) with primary PM emissions in the 2.5-10µm range.

L'objectif de cette thèse est de réaliser un bilan des aérosols atmosphériques sur le bassin méditerranéen et de caractériser la qualité de l'air de cette région en se focalisant sur des indicateurs d'exposition à long terme. Basés sur des simulations du modèle de chimie-transport MOCAGE, (MOdèle de Chimie Atmosphérique à Grande Échelle), les travaux portent dans un premier temps sur le développement d'un module permettant de prendre en compte les aérosols inorganiques secondaires. Ce module a été validé à différentes échelles et avec différents types de données. Le modèle MOCAGE a ensuite servi à simuler la composition chimique de l'atmosphère sur le bassin méditerranéen pour l'année 2013. Nous avons ainsi pu montrer que le bassin méditerranéen est une région exportatrice d'aérosols. Nous avons également étudié l'impact des émissions anthropiques maritimes et côtières sur le bilan des aérosols et la qualité de l'air dans la région méditerranéenne. / The objective of this thesis are to establish a budget of the atmospheric aerosols on the Mediterranean basin and to characterize air quality over this region based on long term exposition indicators. Based on simulations made with the chemical transport model MOCAGE (Modèle de Chimie Atmosphérique à Grande Échelle), the first part of this work is devoted to the development of a secondary inorganic aerosols module. This module was validated at different scales using a large variety of types of data. The MOCAGE model has then been used to simulate the chemical composition on the Mediterranean basin over the year 2013. We were able to show that the Mediterranean area is an export zone for aerosols. We also studied the impact of marine and coastal anthropogenic emissions on the aerosol budget and the air quality in the basin.

La région Méditerranéenne a été identifiée comme l'une des régions les plus vulnérables aux changements climatiques et anthropiques et constitue un des « hot-spots » mondiaux de crise de l'eau. Dans un tel contexte, les questions relatives à la gestion des ressources en eau se posent de manière accrue. Pour y faire face, des approches de modélisation intégrée associant l'évaluation de la disponibilité des ressources en eau et des demandes en eau sont proposées. Une chaîne méthodologique a été mise en place à l'échelle régionale, considérant des scénarios hydrologiques et d'usages de l'eau sous contraintes climatiques et incluant les objectifs de la Stratégie Méditerranéenne pour le Développement Durable en termes d'efficience hydraulique. Cette première approche permet d'évaluer la situation du stress hydrique en Méditerranée et son évolution à l'horizon 2050. Actuellement, le Sud et l'Est de la Méditerranée doivent faire face à un stress hydrique sévère, voire à une pénurie. D'ici 2050, les ressources en eau disponibles pourraient diminuer de l'ordre de 30 à 50 % tandis que les prélèvements devraient doubler. Le stress hydrique devrait ainsi augmenter sur l'ensemble du pourtour méditerranéen. Néanmoins, si les objectifs d'efficience sont atteints, les prélèvements en eau pourraient se stabiliser, voire même diminuer (10–40 %) dans certains bassins Nord méditerranéens. Le stress hydrique pourrait alors rester faible sur la rive Nord et être tempéré dans certains bassins de la rive Est. Une deuxième chaîne méthodologique a été développée à l'échelle du bassin de l'Ebre (Espagne) afin d'appréhender la satisfaction des demandes en eau environnementales, domestiques et agricoles. Le bassin a été divisé en 9 sous-bassins versants afin de considérer les différentes contraintes hydro-climatiques et l'influence des barrages principaux sur les régimes hydrologiques, auxquels ont été associés 11 sites de demande. Cette approche permet de définir les pressions actuelles sur le bassin et d'évaluer l'évolution de la capacité à satisfaire les demandes en eau sous contrainte de scénarios climatique, d'évolution démographique et d'expansion des surfaces irriguées à moyen terme. Actuellement, les demandes en eau sur le bassin versant de l'Ebre sont satisfaites. A l'horizon 2050, les écoulements printaniers et estivaux pourraient diminuer de 30 à 35 % en différents points du bassin. Les demandes en eau environnementales et domestiques devraient toujours être satisfaites, néanmoins, la capacité à satisfaire les besoins agricoles pourrait ne pas toujours être assurée au cours de la période estivale. Ces deux démarches établissent une confrontation entre l'offre et la demande en eau à différentes échelles et fournissent des indicateurs sur la capacité à satisfaire les demandes en eau sous contraintes climatiques et anthropiques. Elles constituent ainsi des approches originales pour évaluer la disponibilité actuelle et future des ressources en eau, identifier les régions où des tensions d'usages risquent de se produire et mieux orienter les stratégies d'adaptation. Dans un contexte de changements globaux, ce type d'exercice est fondamental pour soutenir les politiques de gestion de l'eau et encourage la co-construction de scénarios entre usagers, décisionnaires et scientifiques. / The Mediterranean basin has been identified as one of the world's most vulnerable regions to climatic and anthropogenic changes and constitutes a water crisis' hot spot. Under such context, questions on water resources management arise. Integrated methodologies taking into account evolution in water resources availability and water demands are thus generated. A first methodology accounting for the Mediterranean basin specific conditions is developed to assess the current and future water stress state of this region. The medium-term evolution of water stress is investigated using climatic scenarios and a water-use scenario based on efficiency improvements following the recommendations of the Mediterranean Strategy for Sustainable Development. Currently, the southern and eastern rims are experiencing high to severe water stress. By the 2050 horizon, a 30–50% decline in freshwater resources is simulated over most of the Mediterranean basin and total water withdrawals are projected to double. Water stress could hence increase over the whole Mediterranean basin. If progresses in efficiency are reached, total water withdrawals would stabilize over the Mediterranean basin and even make them decrease (10–40%) in many northern catchments. Water stress could thus be tempered in some eastern catchments and kept to low on the northern rim. A second integrated water resources modelling framework was developed over the Ebro catchment (Spain) in order to evaluate water allocation for the domestic and agricultural sector as well as for environmental purposes. The catchment was divided into 9 sub-catchments to which 11 demand sites were attributed, in order to take into account the different hydro-climatic regimes and the influence of dams on hydrological regimes. This method defines current pressures applied to water resources and evaluates the evolution of water allocation by the medium term under climatic and water-use scenarios considering population growth and irrigated areas expansion. Currently, water demands are satisfied over the Ebro catchment. In 2050, water resources are projected to decline by 30-35% during the spring and summer seasons. Environmental and domestic water demands should still be satisfied but agricultural water demands could have to face severe water shortages during the summer season. These two modeling frameworks establish a dialogue between water resources and water demands at different space scales and give indexes on the capacity to satisfy water demands under climatic and anthropogenic scenarios. These studies provide original approaches to evaluate water resources current and future availability, to identify the most vulnerable regions to water use conflicts and to better orientate adaptation strategies. In a context of climatic and anthropogenic changes, such frameworks are a first step to better sustain water management policies and to support the co-construction of scenarios between users, policy-makers and scientists.

Cette thèse a pour objet d'étude la filière des plantes à parfum en Méditerranée occidentale et s'intéresse à sa capacité à valoriser les ressources naturelles. Depuis une dizaine d'années, les matières premières naturelles suscitent autant l'intérêt des fabricants de parfums et de cosmétiques que celui des consommateurs, dans un contexte proprice au développement durable. Elles font également l'objet de mises en valeur territoriales : paysages, techniques industrielles, pratiques locales. Autour de ces ressources naturelles s'agrègent des réseaux d'acteurs dont le rôle est d'assurer la compétitivité des systèmes productifs, face à la demande des utilisateurs et face aux nouvelles normes environnementales. Cet effet de réseau engendre des externalités économiques et culturelles ; nous formulons l'hypothèse que ces effets externes, générées par les systèmes productifs de la Méditerranée occidentale, peuvent être des vecteurs d'innovation. Afin de démontrer les synergies et les rapports de force qui se nouent entre les acteurs, et qui sont au cœur de la dynamique des territoires, la thèse propose une démarche comparative en s'appuyant sur les concepts de système productif, de milieu innovateur et d'économie culturelle. Elle emprunte aussi des éléments d'analyse patrimoniale et paysagère. L'étude concerne cinq pays de la Méditerranée occidentale à l'intérieur desquels nous avons sélectionné des territoires d'échantillon : la région française Provence-Alpes-Côte d'Azur, berceau de la parfumerie industrielle, la côte méditerranéenne de l'Espagne et l'axe Madrid-Murcie, l'axe Rabat-Fès et la Vallée du Dadès au Maroc, le Cap Bon en Tunisie, et la Calabre en Italie. / This thesis aims to study raw materials for perfume manufactury's cluster in western Mediterranean and focuses on its ability to enhance natural resources. Over the last decade, natural substances are attracting growing interest from both perfumes and cosmetics manufacturers and consumers, in a context that favoured sustainable development. They also enhance territorial matters such as landscapes, industrial technology, local practices. Furthermore, actors's network ensure the competitiveness of each productive system, as regards new environmental standards. This “network effect” generates economic and cultural externalities ; then, we hypothesize that these externalities generated by the productive systems of western Mediterranean may be vectors of innovation. In order to show the dynamics and the relationships which link the actors of the cluster, and symbolizing the core of territories's dynamics, the thesis focuses on a comparative approach in relying on the concepts of productive system, innovative “milieu” and cultural economy. It also borrows elements of heritage and landscape analysis. The study concerns five countries of western Mediterranean in which we selected representative samples : the french region Provence-Alpes-Côte d'Azur, cradle of industrial perfume, the Mediterranean coast of Spain and the Madrid-Murcia axis, the Rabat-Fez axis and the Dades Valley in Morocco, Cap Bon in Tunisia, and the italian region of Calabria. Then, this study provides refections on interregional cooperation in a Mediterranean approach.