Test Research On Soil Resistance To Wind Erosion Effect In The Different Surface Coverage In Houshan Area Of Inner Mongolia

In view of the fragile ecological environment in the northern arid and semi-arid area,it has seriously restricted agricultural sustainable development as the wind erosion and desertification. We chose typical wind erosion and desertification area in Houshan of Inner Mongolia—Wuchuan county farmland and Marsh River Grassland as testing research objects, and made field in-situ test research with the portable wind erosion tunnel and relative testing equipment developed by Inner Mongolia Agricultural University.The main research contents and conclusions were listed as follows:1. The soil wind erosion multi-factor testing experiments for the conservation tillage farmland according to uniform design method to design testing scheme were completed, and the multi-factor wind erosion mathematical model by partial least square was established in this dissertation. The model analysis and grey correlated calculation showed that each factor has different effect on the net-wind and sediment-wind sediment transport rate. The central wind speed is the first, the vegetation coverage is the second and stubble height is the last one. For the retention rate, its order is opposite to the above order. All factor's interaction has same disciplinarian to the sediment transport rate and the retention rate's interaction. The interaction effect of the stubble height and vegetation coverage ranks the first. The interaction effect of the central wind speed and vegetation coverage ranks the second. The interaction of the central wind speed and stubble height ranks the third. As is shown from the analysis results, the testing scheme is reasonable and feasible, the conclusion is accurate and reliable by adopting the partial least square model and grey correlated theory to analyze the test date.2. The wind erosion modulus of the traditional tillage farmland is obviously higher than the conservation tillage farmland's and the wind erosion increased dramatically when the wind speed exceeded 11 m?s-1. The wind erosion modulus of the traditional tillage farmland varies slowly as the wind speed increased and the critical point of the wind erosion modulus is nonexistent. Moreover, the anti-erosion efficiency is increased with the increase of the central wind speed and vegetation coverage. In the wind speed of 18 m?s-1, under 70 percent coverage, the anti-wind erosion efficiency of the conservation tillage farmland can reach 90.8%.3. Increasing the gravel coverage can restrain soil erosion of the traditional tillage farmland efficiently and change the vertical distribution rule of the sediment transport quantity. The vertical distribution curve of sediment transport quantity gradually appeared"Trunk"feature with the increase of the gravel coverage. The bigger the gavel coverage and the higher the wind speed, the more obvious the"Trunk"features. Under the same coverage, the sediment transport quantity declined slightly with gravel's size increasing.4. The wind erosion object of the conservation tillage farmland basically reached equilibrium-stability state when it passed 5.5m in horizontal direction. The vertical distribution curve of the sediment transport quantity showed the"Trunk"effect which was similar to that of the Gebi surface wind-sand flow. The wind erosion object mainly moved in the near-surface height of 40 cm. It came up to about 90 percent of the wind erosion object's total quantity.5. The multi-factor testing experiments for the grassland erosion were completed according to orthogonal testing scheme, and the multi-factor wind erosion mathematical model by partial least square was established in this dissertation. Model analysis, grey correlated and extreme difference analysis have the same results. Each factor has different effect on sediment transport rate. Namely, the central wind speed locates the first, the vegetation coverage locates the second and the interaction locates the third. As is shown from the analysis results that the method is feasible for grey correlated theory used to analyze soil wind erosion of grassland surface, and the method is accurate and reliable by partial least square of grassland surface wind erosion model to analyze and evaluate the anti-wind erosion capacity.6. By applying grey modeling theory, the grey model for the surface erosion modulus of farmland and grassland with the wind speed changing was established respectively. The model predictive values were basically consistent with the measured values. Therefore, we can further use the model to predict the changing law of the wind erosion module of the farmland and grassland surface with the wind speed changing in the future.