Implications of the Particle Size Characteristics of Nanka Sands Geological Formation on the Agulu/Nanka Gully Erosion Menace (Published)
Gully erosion is one of the major environmental menace defacing the physical environment of the southeastern Nigeria. The geology and soil characteristics of the area has been reported to be amongst the causes of gullying. This study therefore considered some of the physical properties of the Agulu/Nanka gully erosion sites and their implication to gully erosion in the area. Two samples were collected from Agulu and Nanka as sample 1 and 2 respectively. The particle size distribution analyses and plots shows that there is 0% gravel, 98.00% sand particles and 1.94% of silt in sample 1; while we have 0% gravel; 98.50% of sand particles and 1.50% of fine particles in the sample 2. For sample 1, the coefficient of uniformity is 5.6 thus well graded and poorly sorted. While the coefficient of curvature is 0.457 showing that it is moderately graded and sorted. Sample 2 has the coefficient of uniformity as 8 thus well graded and poorly sorted; with the coefficient of curvature as 0.6 showing a moderately graded and sorted sample. From the plots, both samples are predominantly sandy soil with low silt content. The study recommends improved farming techniques, cultural method of soil erosion control and enactment of laws against any activities which will promote erosion growth. Also bioremediation through continuous planting of trees and advanced methods of chemical remediation like grouting would be recommended to stabilize the area against the massive landsliding and continued gully expansion witnessed presently.
Keywords: geologic formation, grading., gully erosion, particle size analysis, sorting