By Mbah, Chinasa Love Edith
The flash flood event of July to August 2010 in Ngwo submerged many buildings, farmlands, business premises and economic trees. Flash floods are common in Ngwo, Udi Local Government Area as any other parts of Nigeria. The regular re-occurrence of flood in the area has also been detrimental to the health of the residents of Ngwo. Therefore, the study aims at examining the effects of flooding on the communities of Ngwo. Data were collected through the use of Handheld Global Positioning System (GSP),Geographic Information System (GIS) and questionnaire. GPS coordinates of Ngwo was collected to determine the topography, the landuse landcover, hydrological map (to identify the areas most prone to flooding) and the slope and soil type. The extent of flood inundation was determined through the use of GIS, SRTM(Shuttle Radar Topography Mission) , Digital Elevation Model ( DEM), Illwis and GPS. Coordinates and other data acquired during the field works at Ngwo were used to identify areas most prone to flood, flood plain and the areas impacted most during flood disaster. Using Illwis data, the digital elevation model of Ngwo was generated in ArcGIS. Land use classes were derived from visual image interpretation of Google earth images using the Multi-Resolution Land Cover classification (MRLC) system and handheld GPS. A total of 400 questionnaires were administered to the respondents in the study area. The questionnaires were distributed using the systematic random technique at interval of five communities in each ten villages. Data collated through questionnaire was coded and analyzed with the aid of statistical package for social sciences (SPSS) version 20. Descriptive statistics which includes frequency, percentages, means and standard deviations were used to summarize the data and answer the research questions. Spearman rho correlation was used in testing the first hypothesis to determine if significant relationship exists between flood disaster occurrence and the effects. In the second hypothesis, ANOVA was used to determine the significant difference among the communities in Ngwo as regards the impacts of flood disaster. The third hypothesis was tested using factor analysis. P value less than 0.05 level of significance was considered. The level of effects were determined as it affects damage to farmland and economic tress (agricultural effects), damage to infrastructural facilities (roads, schools etc), Markets (economic activities), health (loss of lives and injured) and water sources. The areas with high effects were identified. The study reveals that topography, inadequate drainage system and heavy rainfall are major causes of flood disaster in Ngwo The study reveals that the major cause of flood in the study area was the non availability/insufficient drainage system or total absence of the drainage system as the case may be. Also, high rainfall and dumping of waste into the drainage have contributed to the regular occurrence of flood in the area.