To delineate flood risk zones in Abakaliki Local Government Area, a hydrological modelrn(modified rational model) was integrated into the GIS environment by the arithmetic overlayrnoperation method, using operators such as addition and division. The results show that therndelineated areas however experienced same rainfall intensity of 414.2 mm/hr yet the floodrnintensities of these areas differ. For instance, the very high flood risk zone covers about 22.8rnpercent of the study area while the low risk zone covers about 44.3 percent. And the potentialrnareas likely to experience periodic floods with a given input of rainfall are mostly below 40mrnelevation. This study analyzed time series land use/land cover imageries (1986-2016) and 30rnyears rainfall data to examine land use/ land cover changes and rainfall variability asrnunderlying causes for flood risk hazards on downstream community. The LULC change detectionrnshowed that out of the four identified land use classes (Forest, Agricultural lands, Bare lands,rnand Settlements), only settlements changed significantly (5% to 12%). The available rainfallrnrecord for 30-year period of 1986 to 2016 was analyzed to examine the trends of rainfall in thernstudy area and to provide evidence of climate change. Time series graph was constructed tornillustrate the changing trends within the months and years. Statistical analysis was performedrnand the result shows low monthly precipitation changes throughout the years under study. Whenrnthe standard deviation values are examined, it is observed that the standard deviation values ofrnmost months (March, April, May, June, July, August, September and October) are lower than thernmean values of these months indicating that the deviation from the normal distribution is notrnsignificant. Qualitative validation of the modeling results obtained through focus grouprndiscussions (FGDs) with local communities and experts shows that the flood modeling methodrnaccurately classified most communities deemed to be highly susceptible to flood hazard.