Organisation de la filière paysage en milieu urbain

Le paysage est défini par la Convention européenne du paysage comme « une partie de territoire telle que perçue par les populations, dont le caractère résulte de l\u27action de facteurs naturels et/ou humains et de leurs interrelations ». C’est, à maints égards, une construction politique, culturelle et économique des rapports qu’entretiennent les sociétés humaines à l’espace.Quels sont les éléments qui fondent l’organisation sociale de l’espace ? Quels sont les mécanismes à l’origine de son évolution ? Qu’est-ce qui rassemble les individus, malgré la divergence de leurs intérêts ? L’approche économique du paysage s’est développée ces dernières années pour répondre à ces questions et à bien d’autres. Cet ouvrage collectif réunit les résultats récents de la recherche sur ce thèm

Public tendering and green procurement as potential drivers for sustainable urban development: Implications for landscape architecture and other urban design profession

This paper examines whether green public procurements are potential drivers for the development of a landscape architecture professional field in urban design. It proposes an analysis based on the nature of professional skill sets requested and selected by the public tendering process in France. To conduct this research, an analysis of 196 public ‘calls for tender’ and their results are undertaken. Depending on the consideration of ecological concerns, two types of projects are identified: traditional projects and green projects. We examine the impact that ecological issues assert on the position of landscape architecture within the requested skills and within the winning design team. Our main results show that the emergence of green public procurements in France has a significant impact on the demand for new types of professional ‘competencies’ and disciplinary collaborations but not on the results after the selection process.It appears that clients request more multidisciplinarity collaborations to address green criteria. In addition, the landscape architect is always associated with multidisciplinary teams in the requirements of the public call for tender. However, the emergence of new professional skills in the environmental field challenges the expertise of landscape architects and constitutes a competitive field. Counter to the ‘call for tender’ requirements, the selection process favours monodisciplinary teams, often the architect, who is also the favourite for the lead-consultant role. Finally, we discuss how the recognition of landscape architecture as an academic discipline can influence landscape education and how a strong professional body can protect a professional title

Evaluation contingente d’aménités paysagères liées à un espace vert urbain. Une application au cas du Parc Balzac de la ville d’Angers

Cet article propose une évaluation contingente des services esthétiques et récréatifs rendus par un parc urbain. Les dispositions à payer d’un échantillon d’usagers d’un parc urbain dans la ville d’Angers (le parc Balzac) ont été révélées sur la base de deux scénarios reflétant des changements d’attributs paysagers. Les attributs retenus correspondent au degré d’ouverture et à l’effort de fleurissement. Lesupport de paiement proposé repose sur une carte de paiement retraçant les augmentations de la taxe d’habitation à prévoir. Nous avons évalué les facteurs qui augmentent la probabilité de donner une disposition à payer positive. Nos résultats montrent que les aménités paysagères recherchées par les visiteurs de deux scénarios du parc Balzac diffèrent. Dans le premier scénario, seul l’usage lié à une activité de loisirs est exprimé, tandis que dans le second, une appréciation esthétique des aménités est également envisagée

Les Algues Indicatrices De L'eutrophisation Et De La Contamination De La Lagune De Korba (Cap Bon Tunisie)

The concentrations of heavy metals (Fe, Zn, Pb and Mn) were determined in two green algae (Enteromorpha intestinalis and Chaetomorpha Linium) collected from April 2012 to February 2013 in nine stations characterized by the abundance of these algae throughout the year. Determination of Pb, Mn and Zn was carried out by graphite furnace atomic absorption spectrometer while Fe by flame atomic absorption spectrometer (using the Thermo Scientific ICE 3300 AA Spectrometer). An evaluation of the degree of eutrophication is made through the physicochemical study of 31 samples in the surface water. The results underline that Korba is an eutrophic lagoon. The heavy metal concentrations in the water samples decreased in the sequence of Fe >Zn > Mn > Pb, while in Chaetomorpha Linium, Enteromorpha intestinalis and sediment exhibited the same pattern across the sites: Fe >Mn> Zn >Pb. The results show that metal accumulation capacity in both macro-algae varies according to the season and depends on the species. By comparison with other studies in the world, the levels found in the algae of Korba lagoon are relatively high except Mn. Chaetomorpha Linium could be used as an excellent indicator for heavy metals accumulation in Korba lagoon

Agri-environmental Policy and Urban Development Patterns: A General Equilibrium Analysis

This paper investigates the spatial effects that the provision of environmental public goods have on residential location choices in a suburban context. Specifically, a spatial general equilibrium framework is developed to analyze the consequences of adopting an agri-environmental policy promoting the provision of positive farming externalities. We use a static monocentric model of an open city where agricultural bid-rents and agricultural amenities vary endogenously in space, and where the positive externalities associated with agricultural production are valued by households. Consistent with empirical evidence of the potential side effects that conservation policies may have in terms of urbanization patterns and land price changes, we show that under certain conditions implementing an agri-environmental policy may promote additional suburban development. Moreover, we demonstrate that the emergence of disconnected suburban areas may be significantly influenced by the location of land regulated by an agri-environmental policy. Finally, we discuss distributional aspects and show that while introducing an agri-environmental policy has a negative impact on most residential land value, it can have positive effects on farmland and residential land located within the regulated areas, suggesting the non-neutrality of such policies regarding the agents’ assets

Proper Orthogonal Decomposition Analysis of an Airfoil Performances under a Small Vortical Gust

This paper investigates the performance of a non-symmetric airfoil in a perturbed flow for a low Reynolds number by creating small vortical structures. A newly designed two-dimensional numerical tool is used to examine the interaction between the NACA 23015 airfoil and the vortex shedding from a square cylinder. Different airfoil position ratios are numerically simulated concerning the square cylinder G/D (D: square cylinder diameter), the channel centerline T/d (d=D/2), and the vortices scale size D/c (c: airfoil chord length). Results show that the maximum values of the lift and drag aerodynamic coefficients are influenced by the airfoil’s lateral and longitudinal positions. The Proper Orthogonal Decomposition (POD) method is used to identify the most energetic flow structures. For all simulated scenarios, it was found that the first two modes reflect the dominating coherent structures in the flow field. The results also show that a leading-edge vortex is formed over the airfoil. The observed phenomena of symmetric and antisymmetric shedding vortex mechanisms essentially depend on the lateral distance of the airfoil T/d and the vortex scale size D/c. However, the spectral analysis demonstrates that the shedding frequency mainly depends on the gap distance G/D

Experimental Investigation of Tip Vortex Meandering in the Near Wake of a Horizontal-Axis Wind Turbine

The aerodynamic optimization of horizontal axis wind turbine has became one of the most important challenge in the renewable energy field. Over the past few years, many researchers have drawn more attention to the physical processes of the wind energy conversion and precisely the identification of the main causes of energy losses. This paper presents an experimental investigation of near wake dynamics for a model horizontal axis wind turbine in a wind tunnel. The coherent structures downstream of the rotor were studied for different tip speed ratios using the Particle Image Velocimetry (PIV) technique. The influence of the tip vortex meandering was discussed and analyzed using the Proper Orthogonal Decomposition (POD) method. The high-energy modes show that radial meandering is the most energetic source of perturbation in each tip vortex sub-region. The energy fraction of these modes increase gradually during the development of the helical tip vortex filament, which confirm the growth of vortex wandering amplitude in the near wake

Green Consumers, Greenwashing and the Misperception of Environmental Quality

In this paper we analyse a setup where consumers are heterogeneous in the perception of environmental quality. The equilibrium is verified in a setting with horizontal and vertical (green) differentiation. Profits are increasing in the misperception of quality, while, the investment in green quality decreases the more the goods are substitutes. We further consider the introduction of either an emission tax or an environmental standard. The former rises the investment in environmental quality due to the higher cost of production, whereas in equilibrium quality always improves after the introduction of the latter. We show that an optimal environmental standard is an effective regulatory instrument against greenwashing and that the efficacy of the interventions is conditioned to the damage distribution and the aggregate level of emission

Circulating adrenomedullin estimates survival and reversibility of organ failure in sepsis: the prospective observational multinational Adrenomedullin and Outcome in Sepsis and Septic Shock-1 (AdrenOSS-1) study

Background: Adrenomedullin (ADM) regulates vascular tone and endothelial permeability during sepsis. Levels of circulating biologically active ADM (bio-ADM) show an inverse relationship with blood pressure and a direct relationship with vasopressor requirement. In the present prospective observational multinational Adrenomedullin and Outcome in Sepsis and Septic Shock 1 (, AdrenOSS-1) study, we assessed relationships between circulating bio-ADM during the initial intensive care unit (ICU) stay and short-term outcome in order to eventually design a biomarker-guided randomized controlled trial. Methods: AdrenOSS-1 was a prospective observational multinational study. The primary outcome was 28-day mortality. Secondary outcomes included organ failure as defined by Sequential Organ Failure Assessment (SOFA) score, organ support with focus on vasopressor/inotropic use, and need for renal replacement therapy. AdrenOSS-1 included 583 patients admitted to the ICU with sepsis or septic shock. Results: Circulating bio-ADM levels were measured upon admission and at day 2. Median bio-ADM concentration upon admission was 80.5 pg/ml [IQR 41.5-148.1 pg/ml]. Initial SOFA score was 7 [IQR 5-10], and 28-day mortality was 22%. We found marked associations between bio-ADM upon admission and 28-day mortality (unadjusted standardized HR 2.3 [CI 1.9-2.9]; adjusted HR 1.6 [CI 1.1-2.5]) and between bio-ADM levels and SOFA score (p < 0.0001). Need of vasopressor/inotrope, renal replacement therapy, and positive fluid balance were more prevalent in patients with a bio-ADM > 70 pg/ml upon admission than in those with bio-ADM ≤ 70 pg/ml. In patients with bio-ADM > 70 pg/ml upon admission, decrease in bio-ADM below 70 pg/ml at day 2 was associated with recovery of organ function at day 7 and better 28-day outcome (9.5% mortality). By contrast, persistently elevated bio-ADM at day 2 was associated with prolonged organ dysfunction and high 28-day mortality (38.1% mortality, HR 4.9, 95% CI 2.5-9.8). Conclusions: AdrenOSS-1 shows that early levels and rapid changes in bio-ADM estimate short-term outcome in sepsis and septic shock. These data are the backbone of the design of the biomarker-guided AdrenOSS-2 trial. Trial registration: ClinicalTrials.gov, NCT02393781. Registered on March 19, 2015