Simulation Soil Erosion During the Period of Thawing Based on Optimal Regression Subsets
Soil erosion mainly occurs during the period of thawing in spring because of high soil moisture and incomplete thaw.The effects of soil depth of thawing,soil moisture content and rainfall intensity on soil erosion amount were studied during the period of thawing in spring with methods of outdoor freezing,indoor thawing and simulated rainfall.The levels of soil moisture content were set as 20％,30％ and 40％,the levels of rainfall intensity were 0.8,1.0,1.2mm·min-1,and the depths of initial soil thawing were 5,10,15mm,respectively.Orthogonal experiment was carried out with 3 levels for 3 factors,meanwhile highly significant nonlinear regression equations of soil erosion amount and the time producing runoff were established respectively with optimal regression subsets,and both of the regression equations were very significant.The results showed that in the regression equations of soil erosion,the initial thawing depth and its square,the square of initial soil moisture content,as well as the interaction between any two factors among them were highly significant except soil moisture content.The regression equations of time producing runoff,the initial soil moisture content was highly significant,while the depth of thawing and its square,rainfall intensity,the square of soil moisture content,as well as the interaction between the depth of thawing,soil moisture content and rainfall intensity were significant.The findings would provide a theoretical foundation for the revelation of soil erosion mechanism during the period of thawing in spring,as well as the prediction of soil erosion amount at the same period.The method of optimal regression subsets can be applied to the soil erosion research.
orthogonal experimentamount of erosionrunoff timeoptimal regression subsetsnonlinear regression equation
国家科技期刊平台
NSTL
万方数据
维普
