ABSTRACT

Flash floods are a recurring problem in many parts of Cameroon during the rainy season, causing loss of lives and property damage. Buea, located in the South-West Region, is particularly vulnerable due to its steep terrain and high annual rainfall. This study aimed to identify and analyze the primary factors exacerbating flash flooding in Buea.

A mixed-methods approach was employed, incorporating field observations, interviews with local residents, and analysis of rainfall and elevation data from 2016-2023. Precipitation levels during the months of July through October were found to strongly correlate with flood events. Rainfall intensity exceeded 150mm in many locations during major floods in 2015 and 2018. Topographic factors such as narrow river channels and insufficient drainage infrastructure were also shown to impede rapid water runoff.

Interviews revealed unsustainable agricultural and construction practices have contributed to deforestation and loss of protective vegetation along riverbanks. As the population expands, more homes and buildings are located in high-risk flood zones. Limited education around hazards and preparedness has left communities unready to respond effectively.

The findings of this research have implications for designing improved flood forecasting and early warning systems. Adaptation strategies such as reforestation, upgrading drainage, and restricting development in floodplains could help build community resilience if implemented appropriately. Overall, the study sheds light on the complex interplay of climatic, environmental and socioeconomic forces influencing flood risk in Buea.

CHAPTER ONE: INTRODUCTION

1.1 Background to the study

Flash floods are a recurring problem affecting many parts of Cameroon during the annual rainy season from June to October. Extreme precipitation events can overwhelm drainage systems, transforming small streams into raging torrents capable of causing destructive inundations. The mountainous regions of the country are especially at risk due to steep terrain and high concentrations of rainfall.

Located in the South-West Region near the Nigerian border, Buea experiences intense seasonal downpours each year. The municipality holds the record for highest average annual rainfall in Cameroon, with over 7,000mm precipitated annually (Cameroon Meteorological Service, 2020). Its hilly topography features numerous narrow river valleys prone to rapid runoff during heavy storms. Several neighborhoods are constructed on steep slopes with limited flood mitigation structures in place.

Major floods have battered Buea with increasing frequency and severity in recent years. In 2015, over 150mm of rain fell in a 24-hour period, overwhelming drainage ways and submerging large sections of the city (Red Cross Cameroon, 2015). Dozens of homes were destroyed and two lives were lost. A similarly catastrophic event impacted Buea again in late 2018. Preliminary disaster assessments indicated human activities like deforestation may be exacerbating floods by reducing watershed infiltration capacity (OCHA, 2019).

As climate change effects intensify extreme weather worldwide, more erratic and intense precipitation is projected for Cameroon in coming decades (IPCC, 2014). A growing population is also increasing development pressure on vulnerable land in Buea. With lives and livelihoods at stake, understanding the complex drivers of floods has become an urgent priority to strengthen community resilience and adaptation. However, little empirically-driven research on causes has been undertaken to date in this region.

This qualitative study aims to address that gap by investigating contributing factors holistically through field observations, interviews and geospatial analysis methods over Buea’s 2018 rainy season. Findings will inform improvements to flood forecasting, emergency preparedness planning and sustainable development policies.

1.2 Problem statement

Flash floods represent a significant and rising threat to communities in Buea, Cameroon. As the effects of climate change intensify extreme weather events worldwide, more erratic and intense precipitation is projected for Cameroon in coming decades. At the same time, rapid urbanization is increasing the portion of the local population exposed to flood risks through development in vulnerable areas. These coupled pressures amplify the need to enhance resilience against flash flooding through improved mitigation, preparedness, and adaptation strategies informed by empirical research.

While flash floods recur on an annual basis in Buea, damaging a number of homes and businesses each rainy season, their underlying environmental, social, and climatic causes have not been sufficiently investigated. Previous disaster response efforts have been primarily reactive in nature due to a lack of understanding of the holistic drivers of inundation. Without a robust evidence base, long-term risk reduction plans remain limited in scope and efficacy. Critical geospatial data on factors such as rainfall patterns, terrain influences on runoff, hydrological infrastructure deficiencies, and the impacts of land use/cover changes on watershed permeability are not currently being leveraged to their full potential to combat flooding.

Community stakeholder engagement and education has also been inhibited by an absence of clear communication around forecasting and early warning. This knowledge gap has led to inadequate preparedness for flooding emergencies among at-risk populations. Going forward, addressing these issues through targeted empirical research will be pivotal to building flood resilience in Buea as climate volatility increases. Therefore, a mixed-methods study approach that investigates both physical/climatic and human drivers of floods through observation, geospatial analysis and participatory methods is warranted.