Target Oriented Procedure for Erosion Control in Nanka/Agulu Axis of Nigeria
Publication Date : 01/03/2017
This work addresses the gully erosion problems of the Nanka/Agulu area of Anambra State, Nigeria. Field reconnaissance and observation visits were made to five (5) major erosion sites in the study axis between the months of November, 2011 and February, 2015 to obtain a first hand and on-the-spot assessment of the degree of erosion menace in these areas, and to collect soil samples for laboratory analyses. The collected soil samples were subjected to visual inspection before classification tests. The investigation/field work was carried out and conducted in accordance with the guidelines given in the general specification (erosion control) vol.11 of the Federal Ministry of Works and Housing, and where necessary, the British Code of Practice for site investigation (C.P.2089). The representative soil samples were subjected to the Natural Moisture Content, Atterberg Limits, Mechanical Sieve Analysis, Compaction and Triaxial Compression tests to ascertain their nature, texture and erodibility. Data obtained from the sites and from these tests were inserted into mathematical formulations on the management of erosion problems. This enabled the quantification of the soils' erodibility, erosion estimation and the recommendations on the management of the erosion problems in the study axis. With data obtained at the sites, computations and designs of Revetments along the sides of the Gullies, design of Run-off/Flood Drainage Channels, and, design of Run-off/Flood and Sediment Retarding Structure (Sedimentation Weir) were carried out. Results revealed that proper Soil Conservation Designs, Flow Velocity Control, Reduction of Soil Segregation (Rainfall Erosivity), Soil Conservation Measures, proper Management of Human Activities. Application of Agro-forestry. Ground Cover Establishment, and, construction of necessary Erosion Control Structures at the proper locations in the study-axis will adequately help in checking the erosion problems.
No. of Downloads :