Etude des risques naturels liés aux interactions entre les mouvements de masse et le réseau hydrographique dans la région des lacs Kivu et Tanganyika

This PhD thesis is entitled ‘Etude des risques naturels liés aux interactions entre les mouvements de masse et le réseau hydrographique dans la région des Lacs Kivu et Tanganyika ’ (in English : ‘Analysis of natural hazards related to the interactions between mass movements and the hydrographic network in the Lake Kivu and Lake Tanganyika regions’). The study area belongs to the East African Rift Valley. It is also located in a typically tropical climatic environment. Thus, it is regularly affected by landslides and recurring floods. Flood and landslide issues are often analysed separately while there are many cases of disasters where those types of hazards interacted; this is particularly true for the target region. Therefore, this thesis is focused on the interactions between those two types of natural hazards in order to provide clues to better assess them together. More specifically, this work will provide an inventory of the hydrological and geological hazards, will investigate cases experienced in the region, will highlight the level of exposure to direct and / or indirect impacts of landslides and will finally produce a related assessment. A methodology coupling field observations and measurements as well as laboratory analyses was developed. Laboratory studies were supported by remote sensing and numerical models to study slope stability as well as the triggering and evolution of landslides. Hydraulic simulations involving dam failure scenarios were run to assess related effects on floods in the downstream area. Important decision-support tools in the environmental and land management, urban and hydroelectric plant planning have been developed. They consist of maps illustrating the relative territory and hydrographic network susceptibilities to floods and landslides. Moreover, the configuration of the interplay mechanisms between landslides and floods is designed and discussed. These results make a valuable contribution to the understanding of geological and hydrological hazards in the Lake Kivu and Lake Tanganyika regions. They are also an important asset for further studies in this field and can be used for other zones located in a similar natural hazard context.

Grantor dc:publisher

ULiège - Université de Liège

Year dc:date

2019

Author dc:creator

• Nibigira, Léonidas

• Vallée du Rift Est Africain
• Inondation
• Tanganyika
• Kivu
• Risque naturel
• Glissement de terrain
• Bujumbura
• Uvira
• Bukavu
• East African Rift Valley
• Natural hazard
• Susceptibility map
• Physical, chemical, mathematical & earth Sciences
• Earth sciences & physical geography
• Physique, chimie, mathématiques & sciences de la terre
• Sciences de la terre & géographie physique

Statement dc:rights

• open access
• info:eu-repo/semantics/openAccess

Licence

• http://purl.org/coar/access_right/c_abf2

Language dc:language

fr

Identifier

info:hdl:2268/235538

OAI identifier oai:identifier

oai:orbi.ulg.ac.be:2268/235538