AN APPLICATION OF REMOTE SENSING AND GIS TO FLOOD STUDY: THE CASE IN FUFORE LOCAL GOVERNMENT AREA OF ADAMAWA STATE

Abstract

The occurrence of flood events has brought a lot of miseries to man and his environment Fufore has continued to experience yearly loss of lives, properties and farmlands to flood events that are caused by heavy rains and discharge of water from Lagdo dam. This research studies flood in Fufore between 1971 and 1994. For this research, a pre-processed SPOT-XS sub scene of Fufore taken on 30th November 1994 was enhanced based on its spectral reflectance intensity (Digital number). It was classified into hills and uplands, water, and flood areas. A topographic map of 1971 was digitized using the manual raster grid method and a DEM of the area for 1971 was generated. The DEM was reclassed into uplands and hills, lowlands, and flood areas. The areas that are less than the flood threshold value of 166.5m above mean sea level are reclassed as the flood areas on the DEM. When the flood areas of 1994 and 1971 were compared, the results revealed that the floodable areas had tripled from an estimated is coverage of 16.28% in 1971 as against 50.40% in 1994. And also the NDVI index is high between 0.50-1 on the hills and uplands compared to very low index of less then 0.25 on the floodable areas, thus signifying sparse and dry vegetation in the floodable areas. These results show that floodable areas are on the increase, and unless government takes measures to mitigate it, Fufore will continue to be endangered to flood every year.