Browsing by Author "Wijffels, Anja"

Now showing 1 - 5 of 5

Finding sites meeting compactness and on- and off-site suitability criteria in raster maps
(2010-02-16) Vanegas, Paul; Wijffels, Anja; Cattrysse, Dirk
This paper presents an evaluation of the Heuristic for Locating Cells (HLC) for identifying optimal sites in raster maps. The optimal sites are the result of a trade-off between the on-site suitability of individual cells, their spatial configuration, and their off-site impact at the watershed outlet. The evaluation is targeted to a case of reforestation in two sub-basins within the Tabacay catchment in the southern Andes of Ecuador. The case is set up to locate a predefined number of cells 1) forming a compact patch, 2) minimizing sediment reaching the watersheds outlet, and 3) maximizing cell-specific performance, i.c. carbon sequestration and monetary income as a result of reforestation with pine trees. The evaluation confirms that the heuristic is capable of identifying high quality compact patches of cells with maximal on-site performance while minimizing sediment delivery.
GI-technology: Adaptive generator of spatio-temporal decision support systems for land use planning
(2010) Wijffels, Anja; Van Orshoven, Jos; Muys, Bart; Cattrysse, Dirk
To deal with the complexity of land use allocation in a spatio-temporally variable context, a generic framework for automated support to multi-objective land use planning is proposed. The framework is rooted in the discipline of land evaluation which is considered a go-between between land resources survey and land use planning. It draws on own experiences and on lessons learnt from literature. It consists of five integrated and interoperable components. The core three ones, the spatio-temporal database, the engine for data query, transformation and analysis and the user interface are adopted from geographical information systems (GIS). A ‘knowledge and model base’ component adds capability for assessing land performance over time. Finally, a multicriteria decision analysis component allows for identifying optimal land units and optimal land use options. The framework’s applicability and the limitations of geographical information technology (GI-Technology) to generate spatio-temporal decision support systems (stDSS) are illustrated with two cases: one in data rich and one in data poor conditions.
El Paisaje Ecuatoriano. La legislación nacional en contraste con las políticas nacionales e internacionales de paisaje
(Universidad de Cuenca, 2015-06-01) Moscoso, Soledad; Wijffels, Anja; Astudillo, Sebastián; Cardoso, Fausto
The geographic location of Ecuador together with its wide altitude range as well as volcanic activity related to the Andean uplift, has granted it a privileged natural landscape characterized by its high biodiversity and exceptional view-sheds. Ecuador has three World Heritage Sites that are located along the glacial valleys and mountain chains of the Andean Mountain Range, where pronounced slopes and constantly changing land use makes them especially vulnerable to landscape alterations. Ecuadorian landscapes are exclusive testimonies of human interaction with the natural environment, giving way to cultural landscapes with prominent historic value. This paper pretends to make some recommendations to develop policies regarding the protection of Ecuadorian landscapes. The aim is to contribute to the debate by reflecting on the current national policies and regulations regarding Landscape and comparing them with the state of art in the region and the rest of the world.
Términos de referencia para la planificación del uso de la tierra en el ámbito forestal y agropecuario en la Cuenca del río Jubones
(2008) Hernández V., Rómulo; Wijffels, Anja
Upgrading geographic information systems to spatial decision support systems
(2011-04-17) Van Orshoven, Jos; Kint, Vincent; Wijffels, Anja; Estrella, René; Bencsik, Gergely; Vanegas, Pablo; Muys, Bart; Cattrysse, Dirk; Dondeyne, Stefaan
A GIS is capable of identifying a set of land units meeting positional, temporal, topological and multiple on-site attribute criteria. Based on the combination of its generic analytical functionalities, a GIS can also be used to rank the alternative land units and propose the best or worst ones in terms of the non-weighted or weighted criteria. More advanced multi-criteria decision methods are however not easily incorporated in the GIS-framework so that extension with dedicated tools is required to upgrade the GIS to a full blown sDSS. In this paper we illustrate this upgrading of GIS to sDSS and we argue that when also temporal alternatives are dealt with, the DSS can be termed spatio-temporal. Three statements are made: (i) the presented rationale is challenged by phenomena of spatial and spatio-temporal interaction, (ii) important research avenues are present in order to optimize topological and off-site decision attributes in the spatial and spatio-temporal decision problems and (iii) the forestry domain is very suitable for study and application of all the mentioned issues due to the explicit spatial and temporal nature of the management issues which must be addressed.