Papers by Annelies De Meyer
Operations and supply chain management : an international journal, Jun 27, 2024
Transportation Research Procedia, Dec 31, 2022
Water of sufficient quantity and quality is indispensable for multiple purposes like domestic use... more Water of sufficient quantity and quality is indispensable for multiple purposes like domestic use, irrigated agriculture, hydropower generation and ecosystem functioning. However, in many regions of the world water availability is limited and even declining. Moreover, water availability is variable in space and time so that it does not match with the spatio-temporal use pattern of the water consumers. To overcome the temporal discrepancy between availability and consumption, reservoirs are constructed. Monitoring and predicting the water available in the reservoirs, the needs of the consumers and the losses throughout the water distribution system are necessary requirements to fairly allocate the available water for the different consumers. In this article, the water allocation problem is considered as a Network Flow Optimization Problem (NFOP) to be solved by a spatio-temporal optimization approach using Mixed Integer Linear Programming (MILP) techniques.Water of sufficient quantit...
Soil Science in a …, 2011
Land evaluation can be considered as the go-between between land resources survey and land use pl... more Land evaluation can be considered as the go-between between land resources survey and land use planning. In a first stage of a land evaluation project, georeferenced land resources data are interpreted in terms of land qualities, performance attributes or, for this study, ...
EDULEARN11 …, 2011
... A second group (22 students, 71% bachelor and 29% master), used the Free and Open Source Soft... more ... A second group (22 students, 71% bachelor and 29% master), used the Free and Open Source Softwares (FOSS) Quantum GIS (QGIS) and GRASS in a supervised self-study (SSS) approach. ... In this course, the FOSS PostgreSQL/PostGIS in combination with QGIS was used. ...
The depletion of fossil fuel reserves and the negative environmental impacts associated with thei... more The depletion of fossil fuel reserves and the negative environmental impacts associated with their use are the driving forces towards the biobased economy. In analogy to today's oil refineries, biorefineries can process renewable biological resources into a range of value-added bioproducts (e.g., bioplastics, paper, transport fuels, electricity, heat). However, the discontinuous (in time) and geographically fragmented (in space) availability of biomass and the relatively high maintenance and logistics costs still compromise the economic viability of biobased products for large scale production and commercialisation. Besides the economical side, also environmental sustainability, energy efficiency and social acceptance are important concerns for the development of a sustainable biobased sector. Poor planning can hurt the environment, damage the image of biobased products, and limit available resources. Comprehensive planning for the supply chain must start prior to or in combination with the expansion of the biobased sector. So, the role that biomass will play in the future will depend upon the extent to which the constraining factors inhibiting trade as well as a sustainable and efficient production of biobased products can be overcome. This dissertation presents the design of a generator (prototype) to create decision support systems to address strategic (e.g., design) and tactical (e.g., inventory and fleet management) decisions in all kinds of biomass-for-bioenergy supply chains with a view to optimise (a combination of) different objectives. This generator encompasses four modules: (1) a database module, (2) a query module, (3) the decision module and (4) a user interface. The database module holds a reference data model which can be used to specify all kinds of biomass-for-bioenergy supply chains. The roots of the reference data model in a generic cradle-to-gate analysis ensures that all kinds of biomass sources, all kinds of biomass destinations and all kinds of handling techniques can be classified into one of the 6 key object types of the data model: (1) biomass production, (2) harvest, (3) collection, (4) pre-treatment, (5) storage and (6) conversion. The database module is connected to the query module to organise and pre-process the initial spatial information and to visualise and post-process the optimisation results. The decision module encompasses the mixed integer linear programming models, OPTIMASS and t-OPTIMASS, to define the strategic and tactical decisions in the supply chain in order to meet the maximum energy output, the maximum profit and/or the minimum environmental impact. OPTIMASS takes into account the geographical fragmentation of biomass to define the optimal supply chain configuration considering one time period, the re-injection of by-products from the conversion process and the changes in biomass characteristics (e.g., moisture content, particle size) due to treatment operations. t-OPTIMASS, the spatio-temporal optimisation model, adds the consideration of temporal variations (e.g., seasonal, regrowth) in biomass availability and energy demand. t-OPTIMASS supports the use of biomass as a sustainable, renewable source by balancing the seasonal availability and regeneration of biomass and the required year-round constant supply of biomass at the conversion facilities. The development of the user interface and the automation of the linkages between the modules are not part of this dissertation. The generator has been implemented to create specific decision support systems for three case studies: (1) the biomass supply chain based on low input high diversity (LIHD) biomass systems in the province of Limburg (Belgium), (2) the municipal wastewater sludge processing chain in Flanders and (3) the Jatropha-to-electricity chain in Mali. The specific DSSs are used to address strategic questions (i.e. new dryer?) as well as tactical questions (i.e. allocation?). The specific DSSs are used to investigate the effect of changes in biomass availability, energy demand, etc. on the supply chain configuration. In general, the results highlight that the requirements imposed to the biomass mixture at the conversion facilities are the main drivers in the decision process. So, OPTIMASS and t-OPTIMASS define the harvesting moment and introduce treatment operations to make sure that biomass is delivered with characteristics that fit best these requirements. In addition, the analyses indicate that storage facilities are indispensable to deal with the temporal availability of biomass, the conflicting temporal (energy) demand and the required constant feeding of the conversion facilities. Additionally, the biomass is preferably grown in the areas where it is also consumed to ensure long term sustainability and to guarantee biomass supply. Directly, nearby biomass availability reduces the transport costs to the conversion facility. Indirectly, the proximity of biomass leads to the reduction of the…
A written permission of the promotor is also required to use the methods, products, schematics an... more A written permission of the promotor is also required to use the methods, products, schematics and programs described in this work for industrial or commercial use, and for submitting this publication in scientific contests. i Doing my master thesis has proven to be a fantastic journey. When an end is coming, I would like to take this opportunity to express my profound gratitude and deep regards to my promoter prof. dr. ir. Jos Van Orshoven for giving me the chance to do this research, and his valuable guidance, advice and encouragement throughout the course of this master thesis. Also, I would like to express my deep sense of gratitude to drs. ir. Annelies De Meyer (supervisor) for her professional guidance, good follow-up, and patience throughout the research. Besides, I want to thank all professors who taught me courses in my master period, because some ideas of my thesis are inspired by their courses. Of course, I need to thank the Faculty of Science in KULeuven for giving me an admission for this master programme two years ago. Friends and parents are important to my life. Thus, I thank them for their company, support and encouragement. Finally, thank for all people who smiled to me. Thanks.
Water, 2019
The allocation of water flowing through a river-with-reservoirs system to optimally meet spatiall... more The allocation of water flowing through a river-with-reservoirs system to optimally meet spatially distributed and temporally variable demands can be conceived as a network flow optimization (NFO) problem and addressed by linear programming (LP). In this paper, we present an extension of the strategic NFO-LP model of our previous model to a mixed integer linear programming (MILP) model to simultaneously optimize the allocation of water and the location of one or more new reservoirs; the objective function to minimize only includes two components (floods and water demand), whereas the extended LP-model described in this paper, establishes boundaries for each node (reservoir and river segments) and can be considered closer to the reality. In the MILP model, each node is called a “candidate reservoir” and corresponds to a binary variable (zero or one) within the model with a predefined capacity. The applicability of the MILP model is illustrated for the Machángara river basin in the Ec...
International …, 2012
Based on a literature review, we conceived the architecture of a spatial (& temporal) decision su... more Based on a literature review, we conceived the architecture of a spatial (& temporal) decision support system (s (t) DSS) that addresses the optimisation of the biomass-to-bioenergy supply chain logistics. In this DSS, three integrated modules will be at stake:(i) ...
Renewable and Sustainable Energy Reviews, 2014
Biomass supply chain optimisation is essential to overcome barriers and uncertainties that may in... more Biomass supply chain optimisation is essential to overcome barriers and uncertainties that may inhibit the development of a sustainable and competitive bioenergy market. The number of research papers presenting optimisation models in the field of bioenergy systems rises exponentially. This paper gives an overview of the optimisation methods and models focussing on decisions regarding the design and management of the upstream segment of the biomass-for-bioenergy supply chain. After a general description of the supply chain and the decisions coming along with the design and management, all selected publications are classified and discussed according to (1) the mathematical optimisation methodology used, (2) the decision level and decision variables addressed and (3) the objective to be optimised. This classification allows users to identify existing optimisation methods or models that satisfy specific requirements. Moreover, the factual description of the presented optimisation methods and models points to opportunities for development of an integrated, holistic approach to optimise decisions in the field of biomass supply chain design and management. Such approach must be based on the consideration of the interrelationships and interdependence between all operations in the entire biomass-for-bioenergy supply chain.
Land Use Policy, 2013
ABSTRACT In a context where several sectors of society compete for space, land use types must be ... more ABSTRACT In a context where several sectors of society compete for space, land use types must be carefully designed and spatially allocated to guarantee a sufficient level of relevant ecosystem services (ES) in a territory of interest. In this respect, contemporary land use planning involves multiple, often conflicting objectives and criteria. Consequently, major benefits can be expected from spatial decision support systems (sDSS) designed to deal with complex spatial allocation problems. This paper presents the generic conceptual framework 'OSMOSE' and its free and open source software implementation, for the generation of specific sDSSs for spatial land use planning. The specific sDSSs generated with OSMOSE are meant to (i) identify land units which meet multiple predefined ES-attribute values for a specific land use type (LUT) and (ii) rank land units for a given LUT according to these multiple ES-attributes. A complementary purpose is to (i) identify and (ii) rank LUTs for a given land unit. Whereas 'identification' is done by means of a threshold query, 'ranking' is based on the Iterative Ideal Point Thresholding (IIPT) method. The proposed framework is extremely flexible as it can accommodate differentially weighted, continuous and/or ordinal attributes with, for the latter, equal or unequal number of classes, alternative land unit definitions and land use types. Moreover, assessments cannot only be made using ES-levels for the land unit/LUT combinations but also in terms of changes in ES-levels after a particular change of LUT. The OSMOSE framework is illustrated by means of the specific sDSS BoLa which is generated to support land use planning in the region of Flanders (Belgium) with focus on soil protection. Four cases are presented in which the decision support varies between the available approaches (threshold - selection, threshold - ranking, IIPT - selection, IIPT - ranking).
CATENA, 2011
... Permissions & Reprints. Soil erosion rates in tropical villages: A case study from Lake V... more ... Permissions & Reprints. Soil erosion rates in tropical villages: A case study from Lake Victoria Basin, Uganda. A ... b National Agricultural Research Organisation, Kawanda Agricultural Research Institute, Kampala, Uganda. Received ...
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Papers by Annelies De Meyer