or a soil sample under a given constraint, for the same flow, soil losses are increasing with increasing slope values (angles);

From this observation we can conclude that erosion is greater for the large slopes; this is in keeping with the formula of the universal soil loss equation. To read [5] - [10].

1) For a given slope, with the same water flow, soil losses change downwards to larger stress samples;

Figure 5. Mass flow chart (g) sorted at flow Q1 = 0.375 L/s.

Figure 6. Mass flow chart (g) sorted at flow Q1 = 0.5 L/s.

Figure 7. Mass series (g) for a sample compacted at C = 0.5 N/m2.

This second observation allows us to note that erosion decreases as soil particle cohesion increases. Read [11] [12] [13] [14].

2) For a given soil and slope constraint, soil losses are increasing towards the largest rainfall flows.

From this last observation we can say that erosion increases with the high intensities of rain. This is in agreement with the authors [15] [16] [17] [18] [19].

5. Conclusion

The realization of a device to study the dynamics of water erosion on soils in the city of Douala, was the subject developed throughout this study and contributed favorably to the collection of data from the Douala V Area having leads to satisfactory results. From these results, it appears that for a given stress soil sample, soil losses are increasing lying for the values of the increasing slopes; whereas for a given slope, soil losses tend to shift downwards to larger stress samples. Also, for a given soil and slope constraint, soil losses are increasing towards the greater rainfall intensities. There is still a way to assess the rate of influence of soil compression on soil loss; this would be possible with a larger database. We also want to see this device improved through the addition of a quantified pressure variation accessory, with automation of some controls making the device more convenient and reliable.

Cite this paper
Enyegue, T. , Fokwa, D. , Mbiakouo-Djomo, E. and Njeugna, E. (2019) A Simple Device to Evaluate the Influence Parameters of the Water Erosion of Bare Sandy-Clay Soils of the City of Douala. Engineering, 11, 819-827. doi: 10.4236/eng.2019.1112056.

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