77 research outputs found
Do stormwater source control policies deliver the right hydrologic outcomes?
International audienceThe number of stormwater source control (SC) regulations adopted by local authorities is rapidly growing in many countries. We can expect that, in the near future, the hydrologic behavior of many urban and periurban catchments will reflect this diffusion. This paper discusses SC regulations through two complementary approaches: starting on three French case-studies, it analyzes how regulations are developed today and identifies a set of shortcuts in policy-making practices. Then, the hydrologic model of a periurban catchment in the Paris region is used to test the impacts that these regulations can produce if widely applied. The main finding is that inertia in policy-making, driving a singular focus on flow-rate based regulations, can produce negative impacts in the long-term. Further efforts on volume-based regulations are advocated, both in terms of research and policy-making. © 2012 Elsevier B.V. All rights reserved
What procedure for a common problem approach in urban water management. The example of an urban stream reopening
ZnO layers deposited by the ion layer gas reaction on Cu In,Ga S,Se 2 thin film solar cell absorbers Morphology, growth mechanism, and composition
Assessing the role of anthropogenic and biogenic sources on PM1 over southern West Africa using aircraft measurements
As part of the Dynamics-Aerosol-Chemistry-Cloud Interactions in West Africa (DACCIWA) project, an airborne campaign was designed to measure a large range of atmospheric constituents, focusing on the effect of anthropogenic emissions on regional climate. The presented study details results of the French ATR42 research aircraft, which aimed to characterize gas-phase, aerosol and cloud properties in the region during the field campaign carried out in June/July 2016 in combination with the German Falcon 20 and the British Twin Otter aircraft. The aircraft flight paths covered large areas of Benin, Togo, Ghana and CĂŽte d'Ivoire, focusing on emissions from large urban conurbations such as Abidjan, Accra and LomĂ©, as well as remote continental areas and the Gulf of Guinea. This paper focuses on aerosol particle measurements within the boundary layer ( 15 nm) of 735 cm-3 stp. Regarding submicron aerosol composition (considering non-refractory species and black carbon, BC), organic aerosol (OA) is the most abundant species contributing 53 %, followed by SO4 (27 %), NH4 (11 %), BC (6 %), NO3 (2 %) and minor contribution of Cl (< 0.5 %). Average background PM1 in the region was 5.9 ÎŒg m-3 stp. During measurements of urban pollution plumes, mainly focusing on the outflow of Abidjan, Accra and LomĂ©, pollutants are significantly enhanced (e.g. average concentration of CO of 176 ppb, and aerosol particle number concentration of 6500 cm-3 stp), as well as PM1 concentration (11.9 ÎŒg m-3 stp). Two classes of organic aerosols were estimated based on C-ToF-AMS: particulate organic nitrates (pONs) and isoprene epoxydiols secondary organic aerosols (IEPOX-SOA). Both classes are usually associated with the formation of particulate matter through complex interactions of anthropogenic and biogenic sources. During DACCIWA, pONs have a fairly small contribution to OA (around 5 %) and are more associated with long-range transport from central Africa than local formation. Conversely, IEPOX-SOA provides a significant contribution to OA (around 24 and 28 % under background and in-plume conditions). Furthermore, the fractional contribution of IEPOX-SOA is largely unaffected by changes in the aerosol composition (particularly the SO4 concentration), which suggests that IEPOX-SOA concentration is mainly driven by pre-existing aerosol surface, instead of aerosol chemical properties. At times of large in-plume SO4 enhancements (above 5 ÎŒg m-3), the fractional contribution of IEPOX-SOA to OA increases above 50 %, suggesting only then a change in the IEPOX-SOA-controlling mechanism. It is important to note that IEPOX-SOA constitutes a lower limit to the contribution of biogenic OA, given that other processes (e.g. non-IEPOX isoprene, monoterpene SOA) are likely in the region. Given the significant contribution to aerosol concentration, it is crucial that such complex biogenic-anthropogenic interactions are taken into account in both present-day and future scenario models of this fast-changing, highly sensitive region
B. Effets d'une surcharge alimentaire en huile de colza sur l'activitĂ© Ă©lectrique du cĆur du rat
International audienc
Résilience des services d'assainissement de la région parisienne face au changement climatique
L'utilisation domestique de l'eau de pluie révélatrice d'un service d'eau et d'assainissement en mutation
Usages de la procédure de débat public dans la planification de l'assainissement urbain
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