A Bayesian approach for incorporating uncertainty and data worth in environmental projects

A data worth model is presented for the analysis of alternative sampling schemes in a special project where decisions have to be made under uncertainty. This model is part of a comprehensive risk analysis algorthm with the acronym BUDA. The statistical framework in BUDA is Bayesian in nature and incorporates both parameter uncertainty and natural variability. In BUDA a project iterates among the analyst, the decision maker, and the field work. As part of the analysis, a data worth model calculates the value of a data campaign before the actual field work, thereby allowing the identification of an optimum data collection scheme. A goal function which depicts the objectives of a project is used to discriminate among different alternatives. A Latin hypercube sampling scheme is used to propagate parameter uncertainties to the goal function. In our example the uncertain parameters are the parameters which describe the geostatistical properties of saturated hydraulic conductivity in a Molasse environment. Our results indicated that failing to account for parameter uncertainty produces unrealistically optimistic results, while ignoring the spatial structure can lead to an inefficient use of the existing data.     

Inspection of non-CO2 greenhouse gases from emission sources and in ambient air by Fourier-transform-infrared-spectrometry: Measurements with FTIS-MAPS

Infrared spectrometry is a versatile basis to analyse greenhouse gases in the atmosphere. A multicomponent air pollution software (MAPS) was developed for retrieval of gas concentrations from radiation emission as well as absorption measurements. Concentrations of CO, CH₄, N₂O, and H₂O as well as CO₂, NO, NO₂, NH₃, SO₂, HCl, HCHO, and the temperature of warm gases are determined on-line. The analyses of greenhouse gases in gaseous emission sources and in ambient air are performed by a mobile remote sensing system using the double-pendulum interferometer K300 of the Munich company Kayser-Threde. Passive radiation measurements are performed to retrieve CO, N₂O, and H₂O as well as CO₂, NO, SO₂, and HCl concentrations in smoke stack effluents of thermal power plants and municipal incinerators and CO and H₂O as well as CO₂ and NO in exhausts of aircraft engines. Open-path radiation measurements are used to determine greenhouse gas concentrations at different ambient air conditions and greenhouse gas emission rates of diffusive sources as garbage deposits, open coal mining, stock farming together with additional compounds (e.g. NH₃), and from road traffic together with HCHO. Some results of measurements are shown. A future task is the verification of emission cadastres by these inspection measurements.     

Nitrogen Oxide Emissions of Boilers in Finland

This article discusses nitrogen oxide emissions from various types of boilers in Finland. The boilers have been classified into 61 classes according to their size, combustion technique, and main fuel. A specific emission coefficient (ng NO₂/J = mg NO₂/MJ) for each class has been determined, based on literature surveys and actual measurements. The total NO_X emission has been calculated for each class, using the emission coefficient and energy statistics. The effect of various techniques for emission reduction has also been investigated. The development of NO_X emissions has been estimated for both the case where no preventing actions have been taken and for four defined cases where alternative reduction measures are assumed

The total NO_X emission from energy production in Finland was 107,000 tons NO₂ in 1987. Seventy-five percent of this amount originated in boilers larger than 1 MWfuel effect (input effect), and the rest in smaller boilers and industrial processes. The most important boiler classes from the NO_X emission’s point of view were coal-fired boilers, with an emission of approximately 38,000 tons NO₂, peat-fired boilers and boilers fired with a mixture of fuels, emitting approximately 12,000 tons NO₂ each.

By 2005, the total NO_X emission from energy production would increase 50 percent to approximately 160,000 tons if left uncontrolled. The emission level would be 140,000 tons if primary reduction techniques are applied, and 110,000 tons NO₂, if catalytic NO_X reduction devices are installed in boilers larger than 300 MW.