Problem 1

Engineering a Day.

OUR PROBLEM FOR TODAY.

Mr. Owen is about moving into his new home, but his excitement is disturbed by the old enemy of every construction ; water. He is fast losing his land to erosion and can't help it any longer. He seeks engineering advice from 'Engineering a Day'. An all discipline engineering consult online.

OUR ENGINEERING ADVICE.

This is a recent construction site. It is only unfortunate that the major components of construction are clearing and grading of land, and both activities disturb and expose the soil. They inevitably increase the area’s susceptibility to erosion. And this place being an urban area, it will be important that you implement some ECMs( Erosion Control Measures) to prevent any further top soil sediments being washed off, and to stop the clogging of drainage systems and future damage to neighbouring properties.

However, we cannot promise to end erosion completely but we can implement some erosion control measures to minimize the cause and effect of erosion on the soil surface.

I tell you what. I will recommend only two ECMs to you; considering the magnitude and the type of erosion here, and also the fact that it is an urban land.

One is vegetation cover.
Vegetation Cover is an efficient way of controlling erosion on urban lands and it is relatively inexpensive. It doesn’t require much, no expert knowledge and no machinery. It is basically planting Vegetation to provide a canopy cover over the soil surface against the direct impact of wind and water energies and a rooting system that holds soil particles together.
Since the water causing the erosion is not man-made but natural rain fall, it will be advisable to plant dense and short vegetation like grasses and shrubs to shield the soil from direct impact of the rain fall. If the cause of the erosion had been wind, then it only remains that we chose the other alternative; which will be dense and tall vegetation. That will be reductive agent against wind velocity hence its erosive effect.
Vegetation with fibrous root systems with fast establishment of roots and ground cover are highly recommended like the shrub.

And the second method will be mulching. It is also the science of covering the surface of the soil against the effects of rain and wind.
Mulching reduces soil temperature fluctuations and conserves water. The type of mulching will depend on the topographical nature of the land. If the sloop is steep, a heavy mulch will be suitable. You can buy geotextiles to cover your land or use normal leaves to cover it. In the former, it is relatively expensive but very aesthetic. While that in the later may be cheaper but may not be appealing aesthetically and decay very fast. Both require periodic replacement which might mean a whole lot of labour.

Other engineering suggestions are welcomed. And constructive criticisms are also welcomed.