Terraces in arid stream valleys a probability model

A model which generates stream terraces in extreme arid environments is developed on the basis of the random occurrence of superfloods in time and in space. The probability of occurrence of the number of terraces in a given desert valley at any point in time is evaluated in relation to varying rates of terrace obliteration. It is shown on theoretical grounds that, if the number of superfloods necessary for obliteration (NSFNFO) is one, the probability for having no terrace is one third, and for having one terrace is two thirds. These findings agree well with computer-generated frequencies.Some geomorphic implications of the analysis are discussed, and the potential for future research based on the approach employed is evaluated.