Factors affecting erosion in a semi-arid watershed.

Abstract

This thesis is the summation of three separate erosion studies that were conducted in the Sycamore Creek watershed. The first, or initial, study is an application of the Musgrave erosion equation to the Sycamore Creek watershed. While the equation predicts erosion with a degree of reliability in the areas for which it was developed, it grossly over-predicts erosion when extrapolated to the semi—arid Southwest. This over- prediction is at least an order of magnitude too high. The second, or channel, study is an application of the Laursen equation to the ephemeral stream that transports the erosion material from the watershed. This study indicates that the Sycamore Creek channel can not transport the erosion material supposedly supplied to it in the initial study. The third, or rainfall simulator, study establishes that the erosion material that could possibly be supplied to the Sycamore Creek channel is at least an order of magnitude less than that predicted by the initial study. Thus it is concluded that an analysis of an ephemeral channel's sediment- carrying capacity, along with an analysis of erosion potential, as derived from a rainfall simulator study, will provide a realistic estimate of yearly erosion from a semi-arid watershed.