Permaculture Reflections
Rainfall in arid regions occurs in large and infrequent events throughout the year. Because the desert environment is a brittle one and because there is so much rain at one time, tremendous erosion occurs. This leads to the creation of scarps and wadis.
Wadi is simply the Arabic word for a riverbed. In an arid region, it's water flow is likely to be ephemeral, particularly in headwaters (where permaculturists are most likely to be working). They are also places where a lot of erosion takes place. Looked at from another perspective, wadis are places where a lot of erosion can be stopped.
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