Walter Hecq

Cost assessment and ecological effectiveness of nutrient reduction options for mitigating Phaeocystis colony blooms in the Southern North Sea: An integrated modeling approach

Nutrient reduction measures have been already taken by wealthier countries to decrease nutrient loads to coastal waters, in most cases however, prior to having properly assessed their ecological effectiveness and their economic costs. In this paper we describe an original integrated impact assessment methodology to estimate the direct cost and the ecological performance of realistic nutrient reduction options to be applied in the Southern North Sea watershed to decrease eutrophication, visible as Phaeocystis blooms and foam deposits on the beaches. The mathematical tool couples the idealized biogeochemical GIS-based model of the river system (SENEQUE-RIVERSTRAHLER) implemented in the Eastern Channel/Southern North Sea watershed to the biogeochemical MIRO model describing Phaeocystis blooms in the marine domain. Model simulations explore how nutrient reduction options regarding diffuse and/or point sources in the watershed would affect the Phaeocystis colony spreading in the coastal area. The reference and prospective simulations are performed for the year 2000 characterized by mean meteorological conditions, and nutrient reduction scenarios include and compare upgrading of wastewater treatment plants and changes in agricultural practices including an idealized shift towards organic farming. A direct cost assessment is performed for each realistic nutrient reduction scenario. Further the reduction obtained for Phaeocystis blooms is assessed by comparison with ecological indicators (bloom magnitude and duration) and the cost for reducing foam events on the beaches is estimated. Uncertainty brought by the added effect of meteorological conditions (rainfall) on coastal eutrophication is discussed. It is concluded that the reduction obtained by implementing realistic environmental measures on the short-term is costly and insufficient to restore well-balanced nutrient conditions in the coastal area while the replacement of conventional agriculture by organic farming might be an option to consider in the nearby future.

Comparison of the environmental damage caused by vehicles with different alternative fuels and drivetrains in a Brussels context

Abstract A comprehensive methodology has been developed to compare the environmental damage caused by vehicles with different alternative fuels, such as CNG, LPG, etc., and drivetrains, such as electric and hybrid drives. This paper describes how the environmental effect of vehicles should be defined and includes parameters concerning vehicle emissions and their influence on human wellbeing and the environment. It then describes how the environmental effect of vehicles could be defined, taking into account the availability of accurate and reliable data. Rating systems are analysed as a means of comparing the environmental effect of vehicles, allowing decision-makers to dedicate their financial and non-financial policies and measures as a function of the ecological damage. Different types of pollution (acid rain, photochemical air pollution, noise pollution, etc.) and their effect on numerous receptors such as ecosystems, buildings and human beings (e.g. cancer, respiratory diseases, etc.) and global warming are considered. The methodology described, known as Ecoscore, is based on a methodology similar to life cycle assessment (LCA) which considers the part played by emissions in certain types of damage (e.g. by using the exposure-response damage function). Total emissions involve oil extraction, transport and refinery, fuel distribution and electricity generation and distribution (well-to-wheel approach). Emissions due to the production, use and dismantling of the vehicle (cradle-to-grave approach) should also be considered. The different types of damage are normalized to make comparisons possible. Hence, a reference value (determined by a chosen reference vehicle) will be defined as a target value (the normalized value will thus measure a kind of distance to target). The contribution of the different normalized types of damage to a single value—Ecoscore—is based on a panel weighting method. This new approach differs from other methodologies in that it has been especially developed for the assessment of the environmental effect of vehicle emissions in an urban context, such as the Brussels Capital Region. Additionally, this methodology not only considers conventional vehicles but can also evaluate all alternative fuels and drivetrains with new vehicle technologies. Some examples of Ecoscore calculation are illustrated.

Etude du poly-l-γ-glutamate de methyle a l'interface air-eau

Abstract The possibility of an α-helix-coil transition of the poly-γ-methyl- l -glutamate spread at the air-water interface has been investigated. The helical conformation of this polypeptide has been shown to exist in the solid film removed from an aqueous support. Starting from a well-defined conformation, the transition is induced by simple methods similar to those used in solution. 1. (i) Effect of the solvent: Addition to the support of dioxane-dichloroacetic acid mixtures of various relative proportions allows the inducement of a transition. 2. (ii) Effect of temperature: An increase of the substrate temperature allows the modification of the interaction forces responsible for the polypeptide structure. The transition phenomenon has been followed by the evolution of the surface pressure. The study at very low surface concentrations enables us to associate with the transition both the surface virial coefficient, which represents specifically the interaction between the spread polypeptide molecules and the molecules of the substrate, and the co-surface which is proportional to the dimension of the macromolecule at the interface.

Contribution of fossil fuels and air pollutants emissions in Belgium since 1980 The role of traffic

ABSTRACT An introduction of air pollution problems in relationship with catalyst technology challenges is given through four aspects : • major air pollution issues involving traffic at different geographical scales; • review of EU vehicle emission regulations from 1970 up until now; • history of emissions of seven pollutants from road vehicles in Belgium between 1960 and 1995 in relation with the regulation put in place; • and finally, a few comments on results of air pollution monitoring network in cities during the last few years. Conclusions on challenges for catalyst scientists and makers are drawn up within the framework of this overview.

Daylight saving time effect on fuel consumption and atmospheric pollution

Abstract On the basis of a traffic analysis made by means of the multiple regression method, it has been shown that the daylight saving time applied in summer months, causes a rise in evening traffic and creates an increase in fuel consumption and hence a higher pollution level in the atmosphere resulting from the products of fuel burning (NO x , volatile organic compounds). It has also been demonstrated — by using the recent version of the US EPA lagrangian EKMA trajectory model — that an increase in primary pollutants and the ‘shifting’ of traffic intensity with respect to sunlight intensity (UV) resulting from the launching of daylight savings time lead to a rise in secondary pollutants, especially in photochemical pollutants: ozone (O 3 ) and peroxy acetyl nitrate (PAN).

External costs of air pollution generated by road traffic in the Brussels urban area

This paper presents a methodology for the assessment of the external costs of air pollution caused by road traffic in the Brussels urban area. This methodology is applied to assess different alternative measures towards sustainable mobility. The general approach follows the sequence: human activity → emissions → concentrations → physical impact → external costs. The methodology developed in terms of this sequence consists of three specific modules. Of these, the first module involves the assessment of air pollutant emissions from road traffic and indoor heating, which are the main urban sources of pollution. The second module establishes the relationship between previously calculated emissions and the concentrations of pollutants in the surrounding atmosphere. The third module assesses the damage in physical and monetary terms on the basis of suitable exposure-response functions. The principal effects covered by the evaluation involve the impact on public health and damage to build...

Environmental vehicle rating system

Part 1: Efficiency and Sustainability in Transport 1.1. Intermodal Versus Unimodal Road Freight Transport - A Review of Comparison of The External Costs 1.2. Environmental Impact of Underground Freight Transport 1.3. Intelligent Speed Adaptation - Increased Safety Through Speed Reduction 1.4. Peering and Investments in Interfaced Networks 1.5. Environmental Vehicle Rating System Part 2: Regulation and Policies to Stimulate Better Performance 2.1. Is the Debate Over the Contestability of Airline Markets Really Dead? 2.2. Decoupling Transport Growth and Economic Growth in Europe 2.3. Travel Plans: Using Good Practice to Inform Future Policy 2.4. Economies of Scale, Efficiency and Government Intervention in Public Transport Part 3: Methods and Models Related to Valuation and Efficiency Analysis 3.1. Dynamics of Global Supply Chain Supernetworks in a New Era of Risk and Uncertainty 3.2. Evaluating Accessibility Gains Produces by New High Speed Train Services 3.3. Evaluation of the Cost Performance of Pre- And Post-Haulage in Intermodal Freight Networks: Analysis of The Interaction of Production Models and Demand Characteristics 3.4. A Methodological Framework to Analyse the Market Opportunities of Short Sea Shipping: The Adaptive Stated Preference Approach 3.5. An Improved Framework for Large-Scale Multi-Agent Simulation of Travel Behaviour 3.6. A Multi-Criteria Approach to the Strategic Assessment of Advanced Driver Assistance Systems

The shared environmental responsibility principle: new developments applied to the case of marine ecosystems

ABSTRACT Estuaries provide advantageous sites for both harbors and fish habitats. In many countries, harbor expansion in estuaries contributed to the decline of fish populations with impacts at the global scale. Restoring these habitats is important to prevent a global biodiversity crisis but is costly and potentially unaffordable for polluters under the Polluter Pays Principle. Such affordability issues prompt decision-makers to reduce environmental targets of restoration programs. Harbor infrastructures destroy fish habitats but generate benefits for society and contribute to the public interest, raising some questions on who is responsible for environmental degradations and who can afford environmental restoration costs? One way to allocate restoration costs is to analyze the amount of harbor services consumed by economic sectors. This paper addresses these questions by computing burden sharing scenarios with an input–output matrix. These scenarios are simulated under the shared responsibility principle to distribute restoration costs among stakeholders in the Seine estuary, France.