Flood Inundation Hazard Modelling of the River Kaduna Using Remote Sensing and Geographic Information Systems

The hazard of and damage caused by flooding cannot be overemphasized in terms of loss of life, property, displacement of people and di sruption of Socio-economic activities as well as the loss of valuable agricultural land due to the attendant inundation of flood plains from floods. Urban flooding is gradually becoming a serious ecological problem in N igeria. Several areas along the coast of the Atlantic ocean and a long major river valleys are affected by floods every year. To g ain better understanding of the flood problem especially for planning purposes, flood risk maps are often required. A c ombination of recent data on flood plains such as land use/cover, river/flood stage, and digital elevation models are used to predict future flood stages and likely impacts. In addition, extreme val ue st atistical m odels s uch as the Gumbel's, distribution are used to determine flood frequencies and different return periods of flood hazards of certain m agnitudes. R emote sensing and GIS and results of an alysis of f lood stage data using Gumbel's Extreme distribution model an d a combination of Digital elevation model an d land use/land cover d ata were used to estimate t he ext ent of flood inundations in dif ferent flood return periods in K aduna Metropolis. Areas und er h igh risk d ue to flooding were a lso determined. The study reve aled that most of the areas lying cl ose t o the R iver Kaduna's flood plain are under severe t hreat to flooding i n dif ferent flood return periods.