Assessment of Flood Risks and Indigenous Knowledge Employed in Flood Management Along The River Gambia

Abstract

Flood risk management in The Gambia faces significant challenges due to the increasing impacts of climate-related disasters, requesting innovative approaches that integrate both Indigenous knowledge (IK) and scientific knowledge (SK). However, studies examining the IK in flood disaster risk management remain scarce, as the current study is oriented towards the contribution of IK to flood risk management in The Gambia. This research employed a mixed-methods design to assess flood risks and climate variation in The Gambia. Data collection included focus group discussions, interviews, and household surveys across 15 flood-prone communities in 7 regions. Thematic content analysis, geospatial tools, and statistical and qualitative software were used to analyze qualitative and quantitative data, resulting in a comprehensive flood risk map and insights into climate variation impacts. This finding reveals that communities along the River Gambia use IK to manage flood risks in the face of increasing hazards. Local people are highly aware of different flood types, distinguishing between beneficial annual flooding and damaging extreme events. Environmental degradation, poor drainage, and climate change were identified as key factors contributing to flooding. Indigenous early warning systems, based on ecological and meteorological signs, were discovered to be helpful to communities preparing for floods. The findings also reveal various coping strategies, such as adjusting homes, changing livelihoods, and managing livestock, which are employed before, during, and after floods. The geospatial analysis results categorize flood risk into five levels, with low-lying areas near river and urban zones facing the highest risks due to poor infrastructure. The very high risk covers 54.740 km² (2.632%); the high risk spans 1,791.300 km² (18.510%); the moderate risk 3,649.325 km² (37.710%); the low risk 3,471.748 km² (35.875%); and the very low risk 510.112 km² (5.271%). The results also highlighted the spatial extent of extreme flood events with buffer ranging from 75.5 to 172.5 meters emphasizing the need for urgent need to improve spatial planning. A survey of 422 households shows that while most have experienced flooding (98.6%), there needs to be more preparedness, with only 2.1% receiving flood warnings. Additionally, climate change-related disasters are a significant concern, with flooding increasing the risk of agricultural losses by 8 times. The findings underscore the importance of integrating IK into flood risk management to enhance community resilience in The Gambia and the sub-region.