ABSTRACT
Taking on the problem of flooding and gully erosion necessitates a thorough understanding of the causes that cause them. This study aims to evaluate flood and gully erosion in Imo State in terms of magnitude and extent. Primary and secondary data were obtained for model flutter and gully erosion vulnerability. For the period 1985–2015, precipitation data were obtained from NIMET. For 1986, 2000, and 2015, respectively, Landsat TM, ETM+, and OLI were procured from the USGS website. The Harmonized World Soil Database has also acquired soil data. The Nigeria Geological Survey Agency acquired a scanned geology map for Imo State. Data from the USGS Website have been collected from SRTM DEM. The renegotiation trend between 1985 and 2015 showed their total and average annual pattern. In order to determine the years of flood between 1985 and 2015, the Standard Precipitation Index (SPI) was used. The flood risk assessment was carried out using the multicriteria analysis and fuzzy logic. To determine the soil erosion, the revised Universal Soil Loss Equation (RUSLE) has been used. Criteria, such as precipitation, runoff, pitch, drainage distance, drainage 74density, soil type, types and land use, geological formation. In accordance with its impact on the Imo State, the criteria were reclassified. Due to the foggy overlay, a flood risk map was created showing that 62.9% of Imo State is situated in a low-risk region, 17.2% in the medium-risk area and 19.9% in the low-risk zone. The low-risk areas include 214 towns and villages, a medium-risk area comprises 64 towns and villages and a high-risk area comprising 52 towns or towns. The amount of soil lost is 0–123,922 ha per tube per year. There are very low, low, moderate, high and very high-risk areas on the erosion risk map. 87.3% of the Imo State lies within the very low-risk zone, 8.1% in the low-risk area of the State of Imo, 4.3% in the middle risk area, 0.3% in the high-risk area, and 0.2% in the high-risk area. In northern Imo State, soil loss was more prevalent. In the southern parts, the effects were smaller because they were low. An effective soil erosion and flood management database has been created.
