| Volumes and Issues Contents of Issue 3 Special Issue |
www.nonlin-processes-geophys.net/15/457/2008/
© Author(s) 2008. This work is distributed
under the Creative Commons Attribution 3.0 License.
Assessing soil surface roughness decay during simulated rainfall by multifractal analysis
1Facultad de Ciencias, Universidade da Coruña, Spain
2Departamento de Edafología, E.T.S. Ingenieros Agrónomos, UPM, Ciudad Universitaria, Madrid, Spain
3Instituto de Física, Universidade Federal da Bahia, Brazil
4Dpto. de Matemática Aplicada, E.T.S. Ingenieros Agrónomos, UPM, Ciudad Universitaria, Madrid, Spain
Abstract. Understanding and describing the spatial characteristics of soil surface microrelief are required for modelling overland flow and erosion. We employed the multifractal approach to characterize topographical point elevation data sets acquired by high resolution laser scanning for assessing the effect of simulated rainfall on microrelief decay. Three soil surfaces with different initial states or composition and rather smooth were prepared on microplots and subjected to successive events of simulated rainfall. Soil roughness was measured on a 2×2 mm2 grid, initially, i.e. before rain, and after each simulated storm, yielding a total of thirteen data sets for three rainfall sequences. The vertical microrelief component as described by the statistical index random roughness (RR) exhibited minor changes under rainfall in two out of three study cases, which was due to the imposed wet initial state constraining aggregate breakdown. The effect of cumulative rainfall on microrelief decay was also assessed by multifractal analysis performed with the box-count algorithm. Generalized dimension, Dq, spectra allowed characterization of the spatial variation of soil surface microrelief measured at the microplot scale. These Dq spectra were also sensitive to temporal changes in soil surface microrelief, so that in all the three study rain sequences, the initial soil surface and the surfaces disturbed by successive storms displayed great differences in their degree of multifractality. Therefore, Multifractal parameters best discriminate between successive soil stages under a given rain sequence. Decline of RR and multifractal parameters showed little or no association.
Full Article (PDF, 407 KB)
Citation: Vidal Vázquez, E., García Moreno, R., Miranda, J. G. V., Díaz, M. C., Saá Requejo, A., Paz Ferreiro, J., and Tarquis, A. M.: Assessing soil surface roughness decay during simulated rainfall by multifractal analysis, Nonlin. Processes Geophys., 15, 457-468, 2008. Bibtex EndNote Reference Manager
