Lena Sanders

Knowledge-based simulation of settlement systems

A knowledge-based approach for estimating and predicting the population growth of a town according to its relative position in a settlement system is presented. This approach allows the explicit representation of hypotheses regarding the urban development process. It makes it possible to systematically test the effect of each of these hypotheses on the results. It also makes the comparison and combination of existing models easier. As a result, the tool we have developed is a combination of elementary models. This tool simulates the spatial effects of urban growth at different scales, from the local integration of peri-urban communes into urban areas towards the transnational competition between large metropolitan areas.

Urban dynamics of some French cities

Abstract Empirical studies of the long-term evolution of the French urban network have showed some regularities which could be interpreted in the framework proposed by the Brussels school, based on the concepts of ‘dissipative structures’: evolution according to deterministic trajectories and bifurcations, fluctuations and auto-organization. This empirical research shows the interest of a dynamic spatial model such as the one presented in this paper. The model brings together many well-known empirical regularities and well established theoretical proposals such as logistic growth, economic base theory, distance decay functions, urban ecology and actors behaviour in an urban context. A first application of this model concerns the evolution of the French agglomeration of Rouen since 1954. The model will be applied to a few French cities in order to estimate the generality of the mechanisms of evolution which are included in the equations. The application shows that there are still some problems, both practical and theoretical, which must be solved before this kind of models will be truly operational. Its principal interest at the moment is theoretical and pedagogical.

Spatio-Temporal Approaches: Geographic Objects and Change Process

Description: Spatio–temporal Approaches presents a well–built set of concepts, methods and approaches, in order to represent and understand the evolution of social and environmental phenomena within the space. It is basedon examples in human geography and archeology (which will enable us to explore questions regarding various temporalities) and tackles social and environmental phenomena. Chapter 1 discusses how to apprehend change: objects, attributes, relations, processes. Chapter 2 introduces multiple points of view about modeling and the authors try to shed a new light on the different, but complementary approaches of geomaticians and thematicians. Chapter 3 is devoted to the construction of spatio–temporal indicators, to various measurements of the change, while highlighting the advantage of an approach crossing several points of view, in order to understand the phenomenon at hand. Chapter 4 presents different categories of simulation model in line with complexity sciences. These models rely notably on the concepts of emergence and self–organization and allow us to highlight the roles of interaction within change. Chapter 5 provides ideas on research concerning the various construction approaches of hybrid objects and model couplings.