FLOOD VULNERABILITY ASSESSEMENT USING FIELD OBSERVATION AND GEOSPATIAL TECHNIQUES; A CASE STUDY OF MAKURDI, BENUE STATE, NIGERIA

Abstract

Flooding is a global phenomenon and one of the most damaging and destructive natural hazards. It has become an annual occurrence in many States, towns and villages in Nigeria. In Makurdi, it occurs along the River Benue because of many factors interplaying together. Worst still, a greater proportion of the populace have little or no knowledge about the risk of living in flood prone zone. Therefore, are not aware of their vulnerability to such hazard. In order to bridge this gap and also, for flood prevention, flood mitigation, flood risk assessment and flood risk management reasons, there is the need for flood vulnerability assessment, so as to generate flood hazard map for the area. Flood vulnerability assessment was therefore, carried out using an integrated field observation and geo-spatial techniques. The research found that, flooding events are mainly caused by multiple factors interplaying together to increases the vulnerability of the study area to flood hazard. These factors were validated by field observation. The factors are , heavy rainfall, raising level of population in the study area, poverty, lack of education and sensitization on the danger of living along flood plains, growth in urbanization, improper disposal of refuse dumps which inturn clogs the drainage channel, inadequate drainage systems and lack of maintenance of existing ones, building of houses along flood plains, sedimentation of the river channel and excessive rainfall and lack of political will on the government to providing basic housing infrastructure. Thus, the research has demonstrated that integrating rainfall data, fieldwork, image interpretation and GIS are very important in flood vulnerability mapping and characterization.