Analysis Of Soil Surface Fissure Network Based On Multifractal Theory

In order to analyze the differences and similarities between cropless soil fissures and cropless soil fissures in farmland,the network model of soil fissures established based on hooke's law was validated.The digital image of farmland soil fissure was obtained by field soil fissure test.Using digital image processing technology and FORTRAN software tool,the obtained farmland soil crack image was binarized,and the crack image simulated by the soil crack model was binarized.The multifractal parameters of soil fissures and simulated fissures with and without crops are calculated,and the generalized fractal dimension Dq,multifractal singularity index a aand fractal spectral function f(?)of the three are compared and analyzed.The results show that:(1)the root system of crops has anchoring effect and certain water holding capacity,so that the moisture content of crops with cracks in the farmland soil decreases more slowly and the moisture content is higher than that of crops without cracks.(2)the multifractal spectral width of crop fractures increases with the development of fractures,and the analysis results of generalized fractal dimension are consistent with the results of multifractal spectral analysis.At the late stage of development,the D0 value of crop fissure is the largest and the range of fissure development is wider.There are crop fissures,and the D1 value in the late development stage is the largest,and the latter measurement of fissures is more sparse locally.The difference between D0 and D2 at the later stage of fracture development is the smallest,indicating that the distribution heterogeneity is better with fracture development.(3)Both crop fissures with and without crop fissures have good self-similarity and multifractal characteristics.The heterogeneity of crop fissure distribution is smaller.The fractal structure of no crop fissure is more complex,and the description of no crop fissure is more accurate than that of soil fissure with crop root system.(4)Simulated fractures have good multifractal characteristics and self-similarity.The irregularity of simulated fractures increases with the development of fractures.When the fracture is no longer obvious,the multifractal spectral width is no longer obvious.The D0 value in the later stage of simulated fracture development is the largest,and the range of simulated fracture development in the later stage is broader.At the same time,the measurement of fracture in the later stage is locally sparser.The difference between D0 and D2 at the later stage of simulated fracture development is the smallest,and the distribution heterogeneity is the better with fracture development.(5)The multifractal spectra of simulated fractures and farmland soil fractures are similar to each other.The multifractal spectral width of simulated fractures differs little from that of farmland fractures,and the multifractal spectral parameters of both are greater than zero.The fractal dimension of simulated fractures is similar to that of farmland soil fractures,and the fitting effect of generalized fractal dimension is good.There is little difference in the variation of the generalized fractal dimension images between them.Therefore,this model can well simulate the image similar to the pattern of farmland fissure network and provide an effective tool for studyi soil fissure.The multifractal parameters can be used as important indexes for comparing the heterogeneity of crop fissures with and without crop fissures,and also provide reference for further optimization of soil fissures model.