UNDERSTANDING THE MECHANISM OF SOIL EROSION FROM OUTDOOR MODEL STUDY

Abstract

A method for obtaining important data on eroded soils, using a one eight experimental slope model is presented. The scope of the investigation herein described encompassed three locations in the south- eastern parts of Nigeria, which are belts of severe erosion, namely Opi-Nsukka, Agulu and Udi, [Fig. 1.] Soil samples were collected from several representative sites for each of these locations and composited into volumes sufficient to be compacted volumes into the fixed-bed flume to a depth of 12cm. mean sediment sizes for the belt soils were, in that order, 0. 326mm, 0.43mm and 0.56mm respectively. The basis of the experiments was an outdoor flume test on the Opi sample throughout the rainy season of June to early October 1996. With an existing mathematical modeling, the results of Opi were extended to the Agulu and Udi situations. Finally by distorted scale laws, data for the natural slopes were synthesised to produce the hydrologic quantities; slope erosion and average infiltration rates for the soils.