Research On The Influencing Factors Of Surface Soil Sheer Strength

soil wind erosion is one global environment problem. It is the main process of land deterioration and desertification in arid and semiarid zones in our country and influence badly resource exploitation and socioeconomic development persistent. Research on soil resistance to wind erosion is very few in our country, this is very adverse to soil erosion prevention and cure and soil erosion evaluation. Basing on the research result of predecessor, this paper studies elementary soil resistance to wind erosion on type zones of the farming-pasture ecotone in the North of Mount Yin of inner Mongolia. This area locate temperature continental semiarid zone. For the seasonal climatic change, at frozen soil thawing season is just the time of soil erosion happening intensely. This is because after freezethaw action, surface soil become very loose, it's cohesive strength and sheer strength reduce sharply, it's resistance to wind erosion decrease, it is very easy to be eroded with gale blowing. So there's a intimate connection between soil wind erosion happen intensely and surface soil cohesive strength and sheer strength reduce sharply. It is probable that soil cohesive strength and sheer strength reflect correctly resistance to wind erosion decrease. Because surface soil is very loose, the field measurement of it's cohesive strength and sheer strength is very difficult. With field and indoor data of cultivated land and common meadow ground soil, We makes a quantitative research on the relationship between ground surface soil sheer strength with ground surface soil temperature,soil moisture and hope forecasting surface soil cohesive strength and sheer strength .We gained flowing conclusions: (1) When soil moisture cuntent is invariant, the sheer strength of frozen soil and thawing soil appear linearity decrease as the increase of soil temperature. (2) When soil temperature is invariant, Sheer strength of thawing soil present a tendency of linear increase at first and afterwards parabola decrease as the increase of moisture content. Sheer strength of frozen soil present a shedding downward para-curve vary tendency as the increase of soil moisture content (3) The more granule content is, the higher ground surface soil sheer strength is.Fine particle content of common meadow surface soil greater than that of cultivated land. So when soil moisture cuntent and soil temperature is invariant, soil cohesives and Sheer strengths of cultivated land less than the soil cohesives and Sheer strengths of common meadow under the same pressure at right angle (4) The decrease of soil moisture content and increase of ground temperature at the sime time is the primary cause of forming loosen ground soil and decreasing soil sheer strength.this variation not only decreases soil resistance to wind erosion but also provides abundtant mass condition for soil erosion, yet is the sticking point that soil erosion fiercely happen every spring. The research on this problem is redounding to Research on soil resistance to wind erosion of other north arid and semiarid zones in our country and provides the theory basis for the further research on the resistance of local ground surface soil and the research on soil wind erosion dynamics. at the same time, this research have academic guidance significance...