Soil Erosion: Possible Solutions

In class on Monday we began the next faze of our project: actually trying to find a solution to soil erosion at the Poilao Dam. We've done a lot of research, so we decided to try and talk globally about all the techniques we've come up with so far.

Below see a picture of some of the techniques and some questions we generated during class:

The starred techniques are ones that we feel comfortable recommending for implementation. The question mark next to the rock riprap + joint planting option shows that we have a lot of questions regarding what to do with the toe of the slope. Depending on the angle of the slope (assumption from pictures: relatively gentle slope), we are thinking of putting a wall of rock and willow at the base of the slope. One reservation we have about this technique is that we have read that it harms the aquatic habitat. We want an effective way to fight soil erosion at the base of the incline, but also don't want to harm the surrounding environment. Another option is a snow fence, which is a wooden fence built in the water a bit beyond the toe of the slope that controls erosion.

As you can see, we still have a lot of questions to answer. Our next task is to work on identifying what kind of vegetation would be good to recommend for planting. Since willow is the best vegetation to use for many soil bioengineering techniques, we are hoping to find a species of willow, or a similarly fast-growing plant, that is native to Cape Verde. 

Stay tuned for our findings!