Abstract

Landslide hazards are regular phenomenon on many landscapes around the world. This is the case with the Limbe II Municipality. Their occurrences produce diverse effects on the environment and the socio-economic development. The aim of this study therefore was to assess the perception of local people on the prevalence of landslides in the Limbe Municipality.

The study used a survey design to collect and analyze the required data. Data collection was done using questionnaires, semi-structured interviews and from secondary sources like text books and scientific articles from the internet. Data analysis was done using descriptive and inferential statistical techniques.

Chi square was used to test the hypothesis. The result showed that landslides have significantly affected the environment in the Limbe II Municipality. Households have had different experiences on the prevalence of landslide hazards. From the field observation, it was seen that majority of the respondents (61.33%) have had no experience on the prevalence of landslide meanwhile those who have had an experience on the prevalence of landslide occupy a smaller proportion (38.67%).

The prevalence of Landslide has produced a number of significant impacts some of which include: human casualties (24.6%), destruction of buildings (27.4%), destruction of farmlands (16.8%), and destruction of biodiversity (13.8%) and water bodies (17.4%). Participants also proposed measures that could be implemented to reduce the adverse effects of landslide hazards.

The suggested measures include: developing policies and guidelines for landslide risk management (43.7%), initiating and promoting capacity building programs amongst others (56.35%). The study gave the following recommendations that the government should develop policies and guidelines for landslide risk Management that implement landslide mitigation strategies, proper polices, legislations and guidelines such issuing building codes on excavations, constructions and grading; and Land use regulations and the management of landslide-prone areas.

Also, the local councils should initiate and promote capacity-building programs that involve training of local people and local government leaders on landslide hazards and their mitigation, in this way creating awareness in society. Finally, the population should adopt feasible measures such as drainage-based water harvesting, promotion of afforestation and reduction of deforestation, reduction of stream and river incision and gully erosion, provision of retaining structures where necessary and planning control where appropriate.

CHAPTER ONE

GENERAL INTRODUCTION

1.1. Background to the Study

Many recent studies have been focused on the causes and effects of landslide across the world. Few researchers have taken in to account the perception people have about landslides. According to Mulugeta (2016), landslides are among the common geo-hazards that cause major economic, social and environmental problems in developing and developed according to Schuster (2007, landslides affect the following aspects of the environment in the Amazon Basin:(1)the topography of the Earth’s surface;(2)the character and quality of Rivers and streams;(3)the forest that cover much of the Earth’s surface; and (4)the habitats of natural wildlife that exist on the Earth’s surface including its rivers, lakes and oceans. Large amount of Earth’s surface and organic material enter streams as sediments as a result of these landslides and erosion activity, thus producing the probability of the water and quality of habitat for fish and wildlife (Banner and Moran, 2005).

The term “landslides, mass movements and slope failure” are used synonymously in this research. Mulugeta (2016), Schuster (2007) and Banner and Moran (2005) have indicated a relationship between rainfall and landslides. Both antecedents and critical intensity of rainfall are important factors in triggering landslides.

In Africa, especially in Sub-Saharan African countries, most of the reported rainfall-induced landslides have taken place during periods of prolonged and heavy rainfall, and have occurred at the end of the rainy season. According to Mulugeta (2016), the majority of mass movements in the various countries in the region such as Ethiopia, Kenya and Nigeria are believed to have occurred as a result of the slope profile.

Landslides are fairly successfully predictable hazards. If these hazards are predicted successfully in advance of their occurrence, economic losses associated with the hazards can be reduced significantly. Especially in recent years, advances have been made not only in the understanding of the mechanisms that trigger landslides but also in techniques for slope instability hazard assessment, prediction and mitigation.

In spite of such achievements, landslides continue to occur in both developed and developing countries with higher casualties in the nations but high economic loss in the industrialized world. Landslides activities are expected to continue in Sub-Saharan Africa for the following reasons:(a) continued deforestation of landslide-prone areas;(b) Increased urbanization and development in landslide-prone areas;and (c)Increased precipitation caused by changing climate.

According to Mulugeta (2016), variable topographical, geographical, hydrological(surface and underground water)and land use conditions mean that many Sub-Saharan African countries especially in Western, Eastern, Central and Southern Africa are frequently being affected by rainfall-triggered landslides.

Evaluation of the relationship between landslides and various factors have revealed that most rainfall-triggered landslides have similar characteristics: mass movements prevail in areas with certain bedrock types, slope gradients, slope shapes, vegetation cover, gully erosion and modifications due to road excavations.

In Cameroon, landslides remain the major geo-hazard and not only cause loss of life but also bring about major economic loss. A case in point here is the Limbe landslide that of the year 2001 where close to 21 lives dead were recorded, and the Lebialem landslide of 20th August 2003 where over 20 persons were registered dead(2004). Biotic destruction by landslide is also common; Nationwide stripping of forest cover by mass movement has been noted in parts of the country such as Limbe, Bamenda Highlands (Sapga Hills, Bamenda falt station, Wainamah), Bagante in the West Region, Manfe-Bamenda Highway amongst others.

Removal of vegetation cover impacts wildlife habitats. The ecological role that landslides play is often overlooked. Landslides contribute to aquatic and terrestrial biodiversity. Debris flow and other mass movements play an important role in supplying sediments and coarse Woody debris to mountain pool/riffle habitat in streams (Moran,2005).

As a disturbance agent, Landslides endanger a mosaic of several stages, soils and sites(from ponds to dry ridges)to forested landscapes. Since 1988,at least five people are killed in Cameroon every year by landslide hazards with a huge effect on infrastructure and the economy in general (Lambi and Cornelius,2004).

Some reported landslide casualties in Cameroon since 1988 include: Bakombo(Melong) landslide in June 1988, Oyomabang (Yaounde) landslide in August 1990,Pinyin(Santa) landslide in September 1992,Bafaka Belue(Ndian) landslide in September 1995,Sho-Belo landslide in September 1997,Guoata(Dschang) landslide in September 1997, Baingoh Belo landslide in July 1998,Anjin Belo landslide in September 1998,Ron(Nwa) landslide in September 2001),Limbe landslide in June 2001,Wabare landslide in July 2003,Bamenda Up station landslide in September 2009 and the Ngwashe (Bafoussam) landslide in August 2019).

1.2. Statement of the Problem

Landslide hazards present a number of significant social and environmental impacts in Fako division, especially and particularly in Limbe subdivision. Landslides have resulted in the loss of lives in the Limbe subdivision, especially the slide that occurred in 2001 where close to 21 human casualties were recorded.

Landslides have also led to the destruction of roads, displacement of population and destruction of property amongst others in this landslide in Limbe is triggered by the influence of slope modification due to human activities such as increased urbanization, road construction, continuous deforestation and increased precipitation caused by changing climatic conditions.

This area falls within the Cameroon Volcanic Line (CVL) that are oriented in a Southwest-Northeast direction, stretching from Sao Tome and Principe in the Gulf of Guinea through Mount Cameroon to Adamawa Plateau.

Many studies have been conducted on the causes and effects and possible solutions to landslide in Limbe but has failed to take in to account the perception of local people on the effects of the hazard. Despite the present knowledge on this hazard, people still settle o hazard prone zones. This is a result of their thought about land acquisition and their ability.

1.3. Research Questions

1.3.1. Main Question

The main question is what are the Local perception on the prevalence of landslides in the Limbe Municipality?

1.3.2. Specific Questions

1. How have landslides occurred in the Limbe Municipality?
2. What are the location perceptions of landslides prevalence in the Limbe Municipality?
3. What are the causes of landslide hazards in the Limbe Municipality?
4. What are the best strategies to be put in place to reduce the prevalence of landslides?

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