Flash flood hazard and coping strategies in urban areas: Case study in Mpazi catchment, Kigali Rwanda

Globally, floods are the most frequent natural disaster, which are becoming a common phenomenon in today`s cities. This is mostly prominent in the developing countries that are facing rapid growth. In particular, the Mpazi Catchment in Kigali/ Rwanda, which suffers from frequent flash flood events, due to the increasing impervious surfaces within the urban environment, which have come to affect a large proportion of the population. Therefore, this research focused on understanding the flood dynamics within this catchment area, as well as analysing people`s perception and the coping mechanisms implemented to mitigate the flash flood problem in the area.
In this case, the hydrological model OpenLISEM, was used by to simulate different rainfall runoff events, where the characteristics of the simulated floods, were then analysed based on the depths, duration and extent, as they were classified to be the most important by the community. It was found out that these flood events were brought about by other factors, such as the topographic nature of the catchment and the extensive and rapid growth, which led to the increase of the unplanned human settlements. The lack of appropriate maintenance of the channels, both by the residents and the authorities in charge
Through the multiple linear analysis, the gender, length of stay and experience with the floods showed to have an influence on the level of perception by the residents, in relation towards the floods.
As for the coping measures, the residents have come to implement various coping measures, which were categorized into three levels, the physical/structural, social and economic coping measures. In anticipation for future flash flood events, the local authorities plan to implement various structural and non-structural measures, which include the repair of the channels, additional culverts and improving the early warning systems.