Didier Bazile

Agent-Based Modelling and Simulation Applied to Environmental Management

The purpose of this chapter is to summarize how agent-based modelling and simulation (ABMS) is being used in the area of environmental management. With the science of complex systems now being widely recognized as an appropriate one to tackle the main issues of ecological management, ABMS is emerging as one of the most promising approaches. To avoid any confusion and disbelief about the actual usefulness of ABMS, the objectives of the modelling process have to be unambiguously made explicit. It is still quite common to consider ABMS as mostly useful to deliver recommendations to a lone decision-maker, yet a variety of different purposes have progressively emerged, from gaining understanding through raising awareness, facilitating communication, promoting coordination or mitigating conflicts. Whatever the goal, the description of an agent-based model remains challenging. Some standard protocols have been recently proposed, but still a comprehensive description requires a lot of space, often too much for the maximum length of a paper authorized by a scientific journal. To account for the diversity and the swelling of ABMS in the field of ecological management, a review of recent publications based on a lightened descriptive framework is proposed. The objective of the descriptions is not to allow the replication of the models but rather to characterize the types of spatial representation, the properties of the agents and the features of the scenarios that have been explored and also to mention which simulation platforms were used to implement them (if any). This chapter concludes with a discussion of recurrent questions and stimulating challenges currently faced by ABMS for environmental management.

Simulating the impacts of climate variability and change on crop varietal diversity in Mali (West-Africa) using agent-based modeling approach

This paper presents a generic, agent-based model that simulates the dynamics of crop varietal diversity at the village level in Mali under different socio-economic, environmental and policy scenarios. The model is designed to integrate social, economic, environmental, and policy factors . A participatory approach with scientists, farmers and policy makers has been implemented to achieve this goal. This approach combines role playing games with agent-based modelling. A set of scenarios are elaborated to evaluate the possible impacts of policy interventions and climate change on agrobiodiversity dynamics. Simulations showed how farmers manage crop varietal diversity to cope with the local climate variability for their annual crop production. The portfolio of varieties increases under stable and good climate condition and decrease under less favourable and variable climate conditions. In addition, depending on the climate condition, farmers allocate preferentially land to varieties with higher yields.

Préservation de l’agrobiodiversité du sorgho in situ au Mali et au Burkina Faso par l’amélioration participative des cultivars locaux

Le sorgho (Sorghum bicolor (L) Moench) est la principale cereale cultivee au Burkina Faso et la deuxieme au Mali. Une diversite varietale importante est geree par les agriculteurs pour divers objectifs de production. Malgre le fort accroissement des besoins alimentaires prevus pour ces deux pays pour les vingt prochaines annees, les rendements en sorgho sont restes faibles et laugmentation de la production est essentiellement due a lextension des surfaces emblavees; de plus, le sorgho subit une erosion genetique. Lobjectif du projet est donc de concilier le maintien de la biodiversite du sorgho et laccroissement de la productivite. Le projet est constitue de sept etapes de travail qui impliquent des equipes pluridisciplinaires de recherche, des services de developpement et des organisations paysannes dune facon participative. Ces dernieres sont majoritaires dans les instances de decisions et dexecution. Le but du projet est de developper une large gamme de nouvelles varietes performantes et adaptees aux conditions climatiques locales et aux besoins et preferences des agriculteurs. Leur diffusion permettrait de preserver la biodiversite du sorgho. (Resume dauteur)