2,146 research outputs found
Future Projections of Urban Waste Flows aand their Impacts in African Metropolises Cities
This paper presents future trends of urban wastes and their impacts on the environment of African cities using plausible mitigation scenarios. To accomplish this, an integrated dynamic model for urban waste flows was developed, tested, calibrated and validated. Its parameter sensitivity was analyzed. Using population projection up to 2052 with different levels of technological implementation, policy enforcement and awareness raising, four runs were executed. The âbusiness as usualâ run showed that with no additional mitigation measures, the environmental quality in Kampala and Dar es salaam Cities deteriorates. The âmore enforcementâ and âmore collectionâ scenarios showed good reduction in environmental loads but they perform less well in resource recovery. The âproper managementâ scenario that combines enhanced technological implementation, awareness raising and policy enforcement, produced the smallest environmental loads, and recovered the largest amount of resources. Thus, the city authorities, general public, community based organisations and Non-governmental organizations would have to increase their efforts in finances and commitment to improve the urban environmental quality and increase resource recovery
LCA of the timber sector in Ghana: preliminary life cycle impact assessment (LCIA)
Purpose - Most life cycle impact assessment (LCIA) approaches in life cycle assessment (LCA) are developed for western countries. Their LCIA approaches and characterization methodologies for different impact categories may not be necessarily relevant to African environmental conditions and particularly not for the timber sector in Ghana. This study reviews the relevance of existing impact categories and LCIA approaches, and uses the most relevant for the timber sector of Ghana. Materials and methods - The study reviewed 23 life cycle inventories (LCIs) and LCAs on forestry, timber, and wood products for relevant impact categories and LCIA approaches for their relevance to the specific conditions in Ghana. This study uses an earlier LCI study of the timber industry as a starting point for an additional LCIA. We next performed a correlation and regression analysis to learn whether wood wastes may function as a reasonable single indicator for land use as proxy for biodiversity loss and the other impact categories. Results and discussion - The literature review shows that no LCI or LCA studies were developed for Africa or the tropics. The LCIA approaches in the reviewed LCAs are indeed shown to take their basis in the environmental problems in western countries and characterization methodologies relating to how these problems manifest themselves in the western world. Characterization methodologies for different impact categories in CML-2000 and other LCIA approaches may not be necessarily relevant to African tropical environmental conditions and particularly not for the timber sector in Ghana. This situation hampers the reliability of our LCIA and points to a serious research gap in LCIA development in general. We applied the scientifically well-recognized CML 2000 to the earlier LCI results and characterized the preliminary selected impact categories of global warming, acidification, eutrophication, photochemical oxidant formation, and human toxicity. The correlation analysis indicated that wood waste is indeed strongly correlated with land use as proxy for biodiversity loss and also positively correlated with the other five potential impact results. It can be concluded that wood waste production is a major driving force for biodiversity loss and a sufficiently good single indicator for all other environmental performance indicators in the timber sector of Ghana. Conclusions - This study and the previous LCI paper are pioneering a field not yet explored, since the correct environmental performance indicators are not yet developed or adapted to tropical conditions. The development of LCIA approaches in the tropics may be the start of a never-ending journey in LCA research in Africa, particularly Ghana
Inventory analysis of the timber industry in Ghana
Background, aim, and scope The timber sector, i.e., forestry and timber industry, plays an important role in the socioeconomic development of Ghana through timber products export. Timber production in this sector is associated with increasing environmental burdens in terms of use of materials and energy, production of emissions and waste, and land use changes. The purpose of this study was to compile a comprehensive life cycle inventory (LCI) to identify the most dominant environmental pressures for five major production lines in the timber industry, and to evaluate the influence of the choice of the functional unit on the results (1 m3, 1 kg, and 1 euro). LCAâs of wood typically base their functional unit on volume, but mass or money may be more appropriate for the rather different products considered in this study. Materials and methods The LCI covers five timber production lines, namely, air-dried lumber, kiln-dried lumber, plywood, veneer, and furniture parts. Three functional units were used for this study to identify the most appropriate basis for a fair comparison of the different timber products (functional units were 1 m3, 1 kg and 1 euro). Questionnaires were administered to thirty selected companies in Ghana. These companies provided data about their material uses, energy requirements, and waste production for their operations from 2000 to 2007. The collected data were first converted into total annual average values, and next extrapolated to reflect the national average data for all 104 active companies. Finally, these data were expressed per functional unit for each of the five product lines on the basis of their production outputs (in volume, mass or money according to functional unit applied). Forest land used changes data was taken from the Ghana Timber Industry Development Division. Emissions for the several activities were taken from literature. Results and discussion Land use change for timber production in Ghana between the estimated periods turned out to be 34.0ÂżĂÂż103 ha per year, which will lead to complete deforestation in the year 2023 if continued. The total energy consumed by the timber sector per year was estimated at 1.9ÂżĂÂż109 MJ per year. The results showed that CO2 emissions by the timber sector activities per year accounted for 745k tons per year and dominate overall greenhouse gases emissions in the timber sector (changes in carbons storage related to land use changes not included). Wood waste by the timber sector accounted for 0.8 million m3 per year. The enormous wastage of wood contributes enormously to the rapid depletion of the countryâs timber resources. The choice of the functional unit influences inventory results. The money-based functional unit, which also seems more appropriate for the different products considered, favors the value-added. Value-added products with strict sustainable forest management policy hold a promising future in terms of sustainability for the timber industry in Ghana. Conclusions This study has yielded good quality primary data unique for LCA research in Africa. This will enhance LCA approaches in Ghana, and allows here identification of the main environmental pressures and their dominantly contributing processes in the timber sector. Land use changes due to forestry form a critical issue and require urgent attention. The chosen functional unitsâ plays a crucial role in the environmental comparison of production line in the timber sector in Ghana. Recommendations and perspectives A comprehensive and transparent inventory for the timber industry provides the industry with an overview of areas in which material and thus economic savings can be made for the good of both environment and the industry finances. Good data keeping in the Ghanaian timber industry will help to build the required research capacity to develop local familiarity and competence in LCA techniques and applying these techniques will help to further certify tropical timber international markets
The local impacts of climate change in the Ferlo, Western Sahel
Recent increases in the accuracy of climate models have enhanced the possibilities for analyzing the impacts of climate change on society. This paper explores how the local, economic impacts of climate change can be modeled for a specific eco-region, the Western Sahel. The people in the Sahel are highly dependent on their natural resource base, and these resources are highly vulnerable to climate change, in particular to changes in rainfall. Climate models project substantial changes in rainfall in the Sahel in the coming 50 years, with most models predicting a reduction in rainfall. To connect climate change to changes in ecosystem productivity and local income, we construct an ecologicalÂżeconomic model that incorporates rangeland dynamics, grazing and livestock prices. The model shows that decreased rainfall in the Sahel will considerably reduce local incomes, in particular if combined with increases in rainfall variability. Adaptation to these climate change projections is possible if reductions in rainfall are followed by destocking to reach efficient grazing levels. However, while such a strategy is optimal from the perspective of society, the stocking rate is determined by individual pastoralists that face few incentives to destoc
A spatially explicit and quantitative vulnerability assessment of ecosystem service change in Europe
Environmental change alters ecosystem functioning and may put the provision of services to human at risk. This paper presents a spatially explicit and quantitative assessment of the corresponding vulnerability for Europe, using a new framework designed to answer multidisciplinary policy relevant questions about the vulnerability of the human-environment system to global change. Scenarios were constructed for a range of possible changes in socio-economic trends, land uses and climate. These scenarios were used as inputs in a range of ecosystem models in order to assess the response of ecosystem function as well as the changes in the services they provide. The framework was used to relate the impacts of changing ecosystem service provision for four sectors in relation to each other, and to combine them with a simple, but generic index for societal adaptive capacity. By allowing analysis of different sectors, regions and development pathways, the vulnerability assessment provides a basis for discussion between stakeholders and policymakers about sustainable management of EuropeÂżs natural resource
Possible Changes in Natural Vegetation Patterns due to Global Warming
The distribution of global vegetation patterns is strongly related to climate patterns. Local differences in soil characteristics and water availability, which are in turn also partly determined by climate, force the global vegetation patterns to become even more pronounced and the local patterns more diverse. The predicted global climate change, due to the increased levels of greenhouse gases, will thus have large impacts on broad-scale vegetation patterns. The Holdridge life zone classification is based on biotemperature (a heat sum), annual mean precipitation and a potential evapotranspiration ratio; it was used in the current paper to create an objective global vegetation (life zone) map. The map was created by interpolation of a large data base of weather stations to a grid of land cells with a resolution of 0.5". The climate scenario for future climate under double CO2 concentrations is based on results of the U.K. Meteorological Office general circulation model. Large changes in vegetation patterns are observed between the life zone classifications of present and future climate. The polar regions decrease most in their extent, and all boundaries between the different latitudinal regions move toward their poles. Most sensitive to climatic warming are the borders between the latitudinal regions. Changes are most clearly observable at the southern and northern edges of the boreal forest region. Limitations of the Holdridge classification to study impacts of climate change are discussed and improved approaches are proposed
Learning Hybrid Process Models From Events: Process Discovery Without Faking Confidence
Process discovery techniques return process models that are either formal
(precisely describing the possible behaviors) or informal (merely a "picture"
not allowing for any form of formal reasoning). Formal models are able to
classify traces (i.e., sequences of events) as fitting or non-fitting. Most
process mining approaches described in the literature produce such models. This
is in stark contrast with the over 25 available commercial process mining tools
that only discover informal process models that remain deliberately vague on
the precise set of possible traces. There are two main reasons why vendors
resort to such models: scalability and simplicity. In this paper, we propose to
combine the best of both worlds: discovering hybrid process models that have
formal and informal elements. As a proof of concept we present a discovery
technique based on hybrid Petri nets. These models allow for formal reasoning,
but also reveal information that cannot be captured in mainstream formal
models. A novel discovery algorithm returning hybrid Petri nets has been
implemented in ProM and has been applied to several real-life event logs. The
results clearly demonstrate the advantages of remaining "vague" when there is
not enough "evidence" in the data or standard modeling constructs do not "fit".
Moreover, the approach is scalable enough to be incorporated in
industrial-strength process mining tools.Comment: 25 pages, 12 figure
The IIASA Database for Mean Monthly Values of Temperature, Precipitation, and Cloudiness on a Global Terrestrial Grid
A database for current climate for a global terrestrial grid has been created using weather records from many different sources. Average monthly temperature, precipitation, and cloudiness values are included in the data set. The weather records were mostly constrained to include at least five observational years from the period 1931-1960. In order to achieve reliable data coverage in regions with especially sparse data, this constraint was not always strictly adhered to. The selected weather records were interpolated onto a grid with a resolution of 0.5 degrees longitude and latitude using a triangulation network followed by smooth surface fitting. Temperature values were corrected to mean sea level; using an estimated moist adiabatic lapse rate and a global topography data set. This technique has enhanced the quantity of the data set, especially for temperature in data-sparse mountainous areas. Precipitation was not corrected, due to more complex relationships between precipitation and altitude. The cloudiness data set, defined as the number of recorded bright sunshine hours as a percent of its potential number, is based on fewer stations and often derived from estimated rather than computed data. Although the major annual cloud dynamics are shown, the regional reliability of the data is low. The final data base can be improved by including more weather records and by using local correction methods, especially for precipitation. The final data set is considered appropriate for use in agricultural, geographical, biogeographical and ecological studies
Expression of Interest ICES/KIS-3 : Thema 4: Hoogwaardig Ruimtegebruik Speerpunt 6
Hoofddoel van dit speerpunt is om zowel de Nederlandse overheid als het bedrijfsleven uit te rusten met een operationele kennisinfrastructuur die toegesneden is op de relatie tussen (antropogene en natuurlijke) klimaatverandering en meervoudig ruimtegebrui
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