What can we do to prevent a landslide?

I live near a small river. A couple of weeks ago, I was strolling along the banks and I noticed this on the other side of the river, a few hundred yards from our house. Today, I decided I would mosey on back to that spot, and this is what it looks like now. This is a picture of our deck and house. The past two summers, we have literally rappelled down that cliff and attempted to plant vegetation in order to sturdy the soil. However, nothing seems to want to grow there. There are a lot of rocks at the base of the cliff, which is good, but I still fear there is a risk or a slide. What can we do to prevent it?