Soil texture fractions and fractal dimension of particle size distribution as predictors of interrill erodibility

Authors : Mohammad Reza NEYSHABOURI, Abbas AHMADI, Hassan ROUHIPOUR, Hossein ASADI, Mehdi IRANNAJAD

Pages : 95-102

View : 12 | Download : 7

Publication Date : 2011-02-01

Article Type : Research Paper

Abstract :Choosing a particular textural fraction as an erodibility predictor is often confusing because various fractions of soil particles have been introduced as erodibility index by many researchers. Recently, advances in fractal theory have introduced a scaling parameter for characterizing soil fragments. The objectives of this study were insert ignore into journalissuearticles values(i); to test the applicability of fractal dimension of particle size distribution insert ignore into journalissuearticles values(PSD); for estimation of interrill erodibility and insert ignore into journalissuearticles values(ii); to study the relationship between interrill erodibility and soil texture components. Samples from 36 soil series with contrasting characters were collected from northwest Iran. The sand fractions were obtained by sieving, while silt and clay fractions were determined by hydrometer. Fractal dimension insert ignore into journalissuearticles values(DB); of PSD was estimated. A rainfall simulator with drainable tilting flume insert ignore into journalissuearticles values(1 × 0.5 m2); at a slope of 9% was used and interrill erodibility insert ignore into journalissuearticles values(Ki); was calculated for 20, 37, and 47 mm h-1 rainfall intensities. The results showed a positive correlation between Ki and clay content. The degree of dependence of Ki to soil texture fractions insert ignore into journalissuearticles values(sand, silt, and clay contents); was greatly affected by the rainfall intensity level. Using either texture fractions insert ignore into journalissuearticles values(sand, silt, very fine sand and sand); or DB did not affect the accuracy of the Ki- predicting models. As use of fractal dimension could follow the principles of uniqueness, fractal dimension of PSD may be applied as an alternative of texture fractions for prediction of interrill erodibility.
Keywords : Key words Erosion predictor, fractal dimension, interrill erodibility, soil texture