Discussion On Surface Soil Particle-Size Distribution Models In The North Of Mount Yin

Soil particle size distribution is the ratio of different size classes soil particle quality among total soil quality, usually it is expressed to the relationship of particle diameter and the corresponding soil particle cumulative mass percentage. In practical application, soil particle distribution curve is generally used to express soil particle size distribution, commonly it is too used to identify soil sorting and approximate judgement soil engineering properties. Due to soil particle size distribution strong affect other soil properties(ground surface shear strength ,soil hydraulic properties),at the present time, many methods have been presented to estimate directly some soil properties measured more difficultly(loose ground surface shear strength),but ,in the course of estimation, complete soil particle size distribution curve is essential. However conventional soil particle analysis result only included finite several data point, which extremely limits the accuracy and applicability of the indirect estimation methods. Conventional soil particle analysis experiment includs a large series of steps, and have a complex operating procedure, and the experiment occupy a long time of the experimenter. Experimental data processing process is very complicated, soil particle size distribution curve is drawing only based on several data point obtained in the experimental procsss. The curve hasn't completed interpolation function, only is the mechanical chain connection of adjacent experimental data point. If appropriate mathematical model can be found to express the soil particle size distribution, the new mathematical model not only have a high accuracy, but also can give the soil particle cumulative mass percentage in the whole diameter range. At the same time, mathematical model can be smart used in the practicle. Even we can judge soil Types based the parameters of the mathematical model. From what I have mentioned above, we can know that creating suitable mathematical model to express soil particle size distribution is very necessary. This paper base on about 87 ground surface particle size distribution data of three different types soil of the farming-pastroral ecotone in the North of the Mount Yin of inner Mongolia,at the meantime,using MATLAB software to obtain the parameters of mathematical model,finilly determine the mathematical model expression. Through comparing the simulating accuracy of five mathematical model that have been used to simulate soil particle size distribution, finding that Imog model and Ifred4P model have a good simulating accuracy, but, this two models have a whole shortcoming, when soil diameter is less than 1mm,simulating value is always greater than measured value about three percentage point. Yet, this diameter range (less than 1mm) has very a very important research purpose to the correspond research in the North of the Mount Yin. Three percentage point error sometime isn't can tolerant for some correspond research. So a new mathematical model is necessary to solve the problems existed above. The new model not only has a more perfect simulated accuracy than other five mathematical model, but also has enough simulated accuracy when diameter less than 1mm.Through a large pilot calculation, a new model is established that has a more high simulating accuracy not only in the whole diameter range but also in the diameter range of less than 1mm.the new model is named Imog2 model. In like manner, Ifred3P model was found having a good simulation to common grassland and closed grassland ground surface soil particle size distribution. This paper not only settled the three different types surface soil particle size distribution models, but also settle the base for overall analysising the influencing factor to wind erosion, and directing local recovery of ecology and agriculture and livestock production.