Entropy-based equation to assess hillslope sediment production

Abstract

A new equation to assess hillslope sediment production, based on physical and probabilistic approaches, is presented. The equation, which allows the computation of the delivery ratio for every event, considers the physical variables of travel distance, stream power, settling velocity and gross erosion. The probability density function that arises from the new formulation is solved using the principle of maximum entropy. Based on data from five watersheds in both tropical and temperate zones, the new delivery parameter K, is calibrated and associated with vegetation cover and conservation practice. The proposed equation is rationally based in relation to parameter Kv. The entropy-based equation was applied to assess sediment yield in two other experimental watersheds, showing good predictability for the set (mean absolute error of 20.8%). No systematic error was found in the analysed data. The entropy-based equation showed good predictability for long-term sets of data and for high-erosivity events, but did not perform well for the low-erosivity ones. Copyright © 2007 John Wiley & Sons, Ltd.