I need advice on dealing with a steep hillside, post-mudslide. After a downpour of 9 inches in 4 hours, two 70+ ft. high trees, assorted tree ferns and shrubs, along with a good portion of a hillside on my property, slid down into a small pond below. We are planting bamboo and vetiver grass to try to hold the hillside and perhaps we will add a gabion or two at the base when the dry season arrives in February. My first question relates to the bamboo - I have an unlimited supply of Bambusa vulgaris Vittata however it grows very tall, very fast - a clump I planted 3 years ago is about 40 feet tall and the old stands of it on my property are over 60 ft. tall. Unfortunately, bamboo of this height will block a considerable portion of my view of a large lake nearby.
My questions are :
1. Is there another bamboo that grows 20 ft. tall or less that would have the same huge, deep root network to help stabilize the hillside?
2. Is some sort of geotextile necessary or helpful?
3. Do the tall trees contribute to the instability in heavy rain and wind? The trees that came down with the hillside were Cecropia obtusifolia which are very fast growing here and which do not seem to have a deep root system. I am concerned that if I plant more trees, they too will act like sails and take to the air as the Cecropias did.
Any advice would be much appreciated - I live in Costa Rica and mudslides seem to be an accepted part of life here in the rainy season but it is quite alarming when it is one's own hill that slides.
