Inductive pattern-based land use/cover change models: A comparison of four software packages

International audienceLand use/cover change (LUCC), as an important factor in global change, is a topic that has recently received considerable attention in the prospective modeling domain. There are many approaches and software packages for modeling LUCC, many of them are empirical approaches based on past LUCC such as CLUES , DINAMICA EGO, CA_MARKOV and Land Change Modeler (both available in IDRISI). This study reviews the possibilities and the limits of these four modeling software packages. First, a revision of the methods and tools available for each model was performed, taking into account how the models carry out the different procedures involved in the modeling process: quantity of change estimate, change potential evaluation, spatial allocation of change, reproduction of temporal and spatial patterns, model evaluation and advanced modeling options. Additional considerations, such as flexibility and user friendliness were also taken into account. Then, the four models were applied to a virtual case study to illustrate the previous descriptions with a typical LUCC scenario that consists of four processes of change (conversion of forest to two different types of crops, crop abandonment and urban sprawl) that follow different spatial patterns and are conditioned by different drivers. The outputs were compared to assess the quantity of change estimates, the change potential and the simulated prospective maps. Finally, we discussed some basic criteria to define a " good " model

Advances in geomatic simulations for environmental dynamics

International audienceModelling environmental dynamics aids in the understanding and anticipation of future evolutions. Their prospective simulation supports decision-making for environmental management. This introductory chapter gives an overview about the context, objectives and opportunities (the challenges), followed by a summery of the methodological approaches commonly used in environmental modelling and simulation. Based on this general opening, the third part presents comprises chapters, which are case studies applying various models to a large array of themes: deforestation in tropical regions, fire risk, natural reforestation in European mountains, agriculture, biodiversity , urbanism, and land management. In this section, authors provide a comparison of these case studies based on several criteria such as objectives , scales, data, study areas, calibration and validation techniques, results and outcome

Límites y Aportaciones de los Sistemas de Información Geográfica para Trazar la Dinámica Espacio-Temporal del Paisaje en Áreas Montañosas Mediterráneas

International audienceDespués de un largo período de intensificación en la explotación de los recursos, los ámbitos montañosos mediterráneos se han visto afectados por una profunda reorganización socio-económica caracterizada por el éxodo rural y el retroceso de las actividades agro-pastorales tradicionales, procesos que han configurado un nuevo paisaje. Esta evolución se manifiesta en la distribución de los tipos de ocupación del suelo, indicadores de la dinámica paisajística. Trazar el pasado más reciente de la montaña mediterránea, cartografiando esta ocupación, plantea problemas ligados intrínsecamente a la naturaleza de la información geográfica y a su diversidad espacio-temporal. Estos obstáculos se manifiestan, por ejemplo, en la evolución no lineal de sistemas complejos y abiertos, en la limitada disponibilidad de datos sobre los estados de estos sistemas en el tiempo, en la heterogeneidad del tipo de información y, sobre todo, en la correspondencia aleatoria entre los estados conocidos y bien documentados, y aquellos momentos claves en la evolución de los distintos ámbitos geográficos. En consecuencia, la consideración del factor tiempo dentro de una dimensión espacial se nos muestra notablemente compleja dentro de los procesos de análisis de interpolación temporal en general y de la detección de ritmos en particular. Estas dificultades en la aproximación temporal de los fenómenos espaciales se verán plasmadas en el estudio de la ocupación del suelo de dos valles que tienen características geográficas comparables aunque presenten comportamientos específicos ligados especialmente al tipo y velocidad de la evolución y al modelo de reconversión económica. Estas diferencias, unidas a otras de índole metodológica, como es la naturaleza de los datos disponibles, han impulsado un planteamiento analítico en cierto modo propio a cada zona. El análisis comparativo de la dinámica de estos dos ámbitos se basa en el empleo de un Sistema de Información Geográfica, herramienta ya utilizada con éxito para los estudios evolutivos (Castro y García, 1993: Comas, 1992; Palacios Morera, 1994; Otero, 1993). Esta elección implica una serie de limitaciones ligadas a la consideración tan sólo de datos que presenten una distribución espacial y que además lo sean a escalas compatibles, y a la integración aproximativa del factor tiempo en los SIG disponibles. Las ventajas consisten en la posibilidad de cuantificar los fenómenos observados, de visualizarlos (en dos y tres dimensiones) y de poner en relación las dinámicas detectadas y los factores y variables del medio en el que se desarrollan. Teniendo en cuenta estos objetivos, y a pesar de haber empleado un SIG vectorial para la configuración de la base de datos y para algunas funciones concretas de análisis (Camacho y Menor, 1997; Camacho, 1998), ha parecido más conveniente la utilización de un SIG en formato ráster, en concreto el SIG Idrisi en su versión 2 para Windows, para la aproximación comparativa espacio-temporal

Benchmarking of LUCC modelling tools by various validation techniques and error analysis

International audienceModelling land use/land cover changes (LUCC) can provide useful information for decision making or for understanding complex social and ecological interactions. The intent of this paper is to provide insights that will help users choose appropriate LUCC models

Comparison of simulation models in terms of quantity and allocation of land change

International audienceOur article illustrates how to compare the outputs from models that simulate transitions among categories through time. We illustrate the concepts by comparing two land change models: Land Change Modeler and Cellular Automata Markov. We show how the modeling options influence the quantity and allocation of simulated transitions, and how to compare output maps from pairs of model runs with respect to a reference map of transitions during the validation interval. We recommend that the first step is to assess the quantity of each transition and to determine the cause of the variation in quantity among model runs. The second step is to assess the allocation of transitions and to determine the cause of the variation in allocation among model runs. The separation of quantity and allocation of the transitions is a helpful approach to communicate how models work and to describe pattern validation

Uncertainty challenge in geospatial analysis : an approximation form the land use cover change modelling perspective

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Una comparacion de programas de modelacion de cambios de cobertura/uso del suelo

International audienceLand use/cover changes (LUCC) are significant to a range of issues central to the study of global environmental change and have thus have received growing attention by decision makers and scientists. Over the last decades, a range of models of LUCC have been developed to meet land management needs, and to better understand, assess and project the future role of LUCC in the functioning of the earth system. This study intends to compare the possibilities and the limits of four modelling approaches: CLUE, DINAMICA EGO, CA_MARKOV and Land Change Modeler (both available in IDRISI). First, a review of methods and tools available for each model was done taking into account how the model carry out the different procedures involved in the modelling process (Estimation of the quantity of changes, finding of the relationship between the explanatory variables and the changes in order to assess the degree of change potential, change allocation, simulation of spatial patterns of changes, model evaluation). The four models were applied to simple case studies and model outputs were compared. Palavras-chave: Land use / land cover change, modelling, GIS