Evaluation de la connectivité des zones humides temporaires au nord-ouest du Sénégal. Approche par simulation multi-agents
Mahefa Mamy Rakotoarisoa, Madina Ba, Awa Fall Niang, Aude Nuscia Taïbi. Evaluation de la connectivité des zones humides temporaires au nord-ouest du Sénégal. Approche par simulation multi-agents. Spatial Analysis and GEOmatics (SAGEO) La Science de l'Information Géographique dans tous ses états, Université d’Avignon, May 2025, avignon, France. ⟨hal-05416995⟩
Wetlands (ZH), essential for biodiversity and ecosystem services (such as flood regulation, carbon storage, and water supply), are severely threatened by urbanization, agriculture, and climate change. Small temporary wetlands (ZHT), although particularly important in dry regions for their hydrological, ecological, and socio-economic roles, suffer from a lack of recognition. Additionally, their connectivity is disrupted by the implementation of infrastructure developments. This study, conducted in northwestern Senegal, explores these issues by combining spatial analysis, spatial simulation, and hydrological modeling. Using cartographic data, satellite images, and high-resolution digital terrain models (DTMs) derived from 3D drone imagery, a multi-agent simulator was developed to analyze hydrological connectivity. Two distinct models were designed: (i) a model to study the connectivity of ponds to watercourses (Stream-Pond Connectivity Indicator) used in the floodplain area of the waalo and (ii) a model to study the interconnectivity of ponds in non-floodplain areas, applied to ZHT of various sizes from the jeeri to the Ferlo (Pond-Pond Interconnectivity Indicator). First results in the waalo allow the extraction and spatialization of a connectivity indicator for the six main ponds in this area over the period from 1998 to 2020, and the reconstruction of potential water flow paths. The results reveal that high-resolution modeling provides valuable insights into hydrological flows and connectivity between wetlands, opening up new perspectives for their preservation and sustainable management.